Hurricane Forecast

Verification of hurricane predictions

Hi all, and its been a while since I have posted, but I will help you catch up to speed on what’s occurring in the tropics and how my summer & hurricane forecasts are panning out in comparison to some of the model guidance & other factors offering support for it.


First of all, remember my hurricane outlook, with this picture from my last post on April 21st, with ideas from this that were derived from my post back in March, ahead of all the other forecasts shown below, thus I can say I was the first to put my hurricane season ideas out there.

My hurricane season forecast

Hurricane Forecast


Looks a lot like the forecast from Joe Bastardi and weatherbell that was released several days later



Here’s a few other forecasts just for entertainment purposes.


Hurricane forecast from an Accuweather forum



Matthew’s hurricane season forecast

2013-hurricane-forecast’s hurricane forecast


Occupyweather’s landfall risk forecast



Weatherworks east coast hurricane risk forecast compared to climatology (a forecast I strongly agree with here)



Now, here is the UKMet office hurricane model forecast for the month of July



The CFSv2 forecast for the same exact time period showing a very similar solution



Now look at my analog years that I complied back on March 24th with 1960, 1969, 1979, 2004, and 2010, pretty close eh?



Interesting in how these model solutions appear somewhat similar to the 500 millibar pattern in the 1938 Long Island Express, a year that was mentioned in my last post with some similarities in the summer outlook and of course late season snows over the midwest, particularly Chicago in the month of April. Notice in the picture below, like in the model forecasts, the notable ridge over southern Canada, a reoccurring theme that seems to be present during significant hurricane landfalls as the ridge helps to “block” the forward progression of tropical cyclones in the SW Atlantic, forcing them into the US coast

500 mb 1938 long Island Express September 19-22 1938



Of course my solution is nowhere near as bad as what the climate models are predicting, a ridge sitting in the position being predicted by the CFS & the UKMET is a signature for hurricane landfalls on the US coast because that region of high pressure located directly to the north of the east coast, southwest Atlantic and Gulf of Mexico helps to focus lower than normal pressures and convergence over this area, which helps to fuel tropical cyclone development. Also consider that as tropical cyclones exit from the tropical easterlies and enter the mid-latitude westerlies they have a tendency to recurve northwest, north, and eventually northeast, however when you have a ridge of high pressure to the north or to the northeast of a storm’s position, this “blocks” (a good reason why these areas of high pressure are also referred to as “blocks” not just high pressure, they are generally interchangeable terms.) the natural progression of these storms into the mid-latitudes and eventually towards the poles, where hurricanes have a tendency to move towards as they are essentially created to balance the difference in temperatures from the tropics to the poles (they’re also referred to as “earth’s air conditioning systems”), thus they have a prolonged movement in the tropical easterlies, which means if you have a storm in the SW Atlantic, as opposed to just going out to sea, the storm will have a tendency to come towards the coast.


Look at the highest hurricane landfalling years since 1948 on the US coast, and look how close this pattern being predicted by the climate models is to the highest hurricane landfalling years on record, not good news for the US.


Also remember the western Pacific typhoon connection, the same pattern over the western Pacific (ridging directly north of the deep tropics focusing lower pressures, convergence and forcing storms closer to land), where there is anomalously large amount of typhoons over the west Pacific hitting the east coast of Asia, specifically Japan and Korea, this teleconnects to increased hurricanes especially on the US east coast.


You can also see the models are also finally beginning to pick up on the increased tropical activity in the Atlantic, indicated by the shades of blue (lower than normal pressures) near the southeastern US coast in the CFSv2 MJJ pressure forecast, a signature that there is increased tropical activity in this area, offering yet more support for hurricane landfalls.



The global water temperature anomalies reveal that at this time, 2004 is very similar to what’s being observed now, with an Atlantic Tripole Signature, (warmer than normal in the tropics, cool in the mid-latitudes, warm again towards the Arctic) typical in warm AMOs, and also the warmer than normal waters over the Indian Ocean (reason why the MJO will be diving so deep into octants 2 & 3, as this area is warmest relative to normal over the global tropics, and thus promotes rising motion, in which the upward MJO is a measure of) Cooler than normal water situated west of the South American coast is also very interesting to note as well as generally warm conditions over the Southern Hemisphere offer further a further similarity with this year and 2004.

May 1, 2004



May 1 this year



The following 2004 hurricane season, which is one of my top 5 analogs for this year featured a barrage of hurricane landfalls on the US coast, particularly in Florida and the Gulf of Mexico.



This video below brings back some personal memories as it was Hurricane Charley in 2004 that I can recall one of my first experiences with the weather (really grabbed my interest from that point on), although it wouldn’t be at least for me, until hurricane Bill in 2009 that I would finally begin to strive to become a weather forecaster.

However, the major difference between this year and 2004 is the cold PDO signal over the north Pacific, indicated by the anomalously warm water north of Hawaii, with a tongue of colder than normal water down the west coast of North America, indicated in the right side of the picture below labeled as the “Negative Phase” of the PDO, which was in place from the 1950s to the late 1970s.



Now, look at just how similar the tracks of the storms in the 2004 & 2005 seasons are to the last time the PDO began to turn cold (although not completely warm), and the Atlantic was in the height of its warm phase, the 1940s.


2000s major hurricane landfalls (all in 2004 & 2005), notice the congregation of storms near Florida & the Gulf of Mexico.

2000s Major Hurricanes US coast


Interestingly, a similar landfall pattern seems to present itself in the 1940s

1940s Major Hurricanes US coast


However, look what happened after the 1940s, once the PDO turned cold, the tracks of major hurricane landfalls shifted to the east coast, as a major trough buckling began to force itself towards eastern North America.

1950s Major Hurricanes US coast


Thus, with such a shift in storm tracks towards the east coast from the Gulf of Mexico and Florida where they have been for the past decade is certainly very concerning for the east coast, especially as although Irene & Sandy have been significant storms in their own respect, the major hurricane drought continues for the US east coast and the US coast in general, as each passing day sets a new record for longest streak in US history since somewhat viable hurricane tracking began around the Civil War.



This shift in storm tracks is becoming evident, however, the US should consider itself lucky the past several years, as many storms have avoided the US coast due to a persistent trough feature near the US east coast.


However, you should take note of the relative region of abnormally higher than normal pressures near the Davis Straits, and although there is a considerable block in this region, which would suggest using the knowledge that regions of high pressure help to block the natural progression of tropical cyclones into the mid-latitude westerlies, that this type of pattern would help to yield a large amount of landfalls, however, this was not the case, except for Irene & Sandy.

2011 hurricane season



2012 hurricane season



Hurricanes Irene & Sandy from last year and 2011 at their peak intensities, almost scary how closely both storms resemble one another.

Hurricane Irene (2011)



Hurricane Sandy (2012)



Now, why would a pattern with blocking directly to the north of the deep tropics over Greenland & the Davis Straits be a hinderance to major hurricane landfalls on the US coast? The answer seems to lie within the blocking itself, as although the block of high pressure does help to block some storms, at least ones in the mid-latitudes, there is an issue with blocking the progression of storms in the tropics. It would seem that the block of high pressure is too far to the north of the deep tropics, and thus the subsequent region of low pressure forcing underneath the block of high pressure, instead of being near the SW Atlantic or southern US coast, is much farther to the north towards the Great Lakes & northeastern US. Considering that storms in the tropics have a stronger tendency to go from the tropics to the poles as they increase intensity, as they are naturally created to act as earth’s air conditioning systems, helping to regulate the temperature gradient between the poles & the tropics, a ridge over the arctic towards Greenland & north of Atlantic Canada helping to force a trough higher up in the mid-latitudes would actually have the opposite effect compared to a similar ridge north of the tropics, like what is observed in major hurricane landfalling seasons. What makes the difference in this case is the fact that a ridge farther to the north towards the arctic like what was observed in the past few years is so far to the north that as tropical systems begin to close in on the US coast, this ridge is far enough to the north to allow a trough in the mid-latitudes to have the ability to force storms out to sea as it is just far enough to the north to allow the effects of the mid-latitude westerlies under the “Ferrel Cell” to kick storms out to sea.

Compare this pattern to high hurricane landfalling years, and the difference is not essentially in whether or not a region of anomalous blocking is to the north of the tropics, rather it is a matter of where the block is in relation to the tropics that makes all of the difference in whether the US is relatively spared from tropical cyclones or hit very hard in a particular season.


500 mb pattern greatest hurricane landfalling years since 1947.


Despite the fact that this pattern with the blocking well into the arctic for most of the year, still resulted in the landfalls of hurricanes Sandy & Irene, and upon looking at those storms, it’s interesting to note in how the block of high pressure that was present near the Canadian arctic & Greenland moves significantly farther to the south, resulting in these storms making landfall on the US coast.

Hurricane Sandy 500 mb pattern

500 millibar pattern Hurricane Sandy


Hurricane Irene 500 mb pattern, interestingly enough has very little in the way of blocking to the north of the storm, other than some high pressure (indicated by the shades of yellow & orange) displaced slightly to the south towards southern Greenland & near Atlantic Canada, merely it would appear that hurricane Irene timed the trough just right to allow it to come towards the east coast.



Another aspect about the pattern that seems to grab my attention is the distribution of the water temperatures over the north Pacific in association with the cold PDO. Compare this year’s water temperatures to the past several years and one can easily see there is a notable difference in the placement of the warmer than normal waters north of Hawaii, associated with the cold PDO.

This year









What really seems to grab my attention in this instance is the fact that compared to the last few years, the PDO, although still considerably cold, the signature of warmer than normal waters naturally found north of Hawaii is located much farther west. What this would imply for is that when you have the cold PDO, the natural trough that is near or just offshore the western US is forced to move westward in response to the westward displacement of the of the water associated with the cold PDO, this in turn, forces a reaction in the pattern downstream over the US & North America, in that the ridge forced over the Great Plains from the western US trough & deep la nina is now forced to migrate farther east as the trough off the west coast moves east, this also means the eastern US trough that has been helping to protect the US coast the last few years will be non-existent, and instead will likely be replaced by ridging, which would imply  for a pattern more supportive of high latitude blocking that favors US hurricane landfalls.


This picture below helps to illustrate this concept


Looking at some of the forecasts for this upcoming summer and using the conditions at hand, once can get an idea as to where exactly the pattern will be going this summer over the arctic, perhaps giving an indication as to where precisely the blocking will be north of the tropics. First of all, consider the fact that the Nov-Apr period has been the snowiest on record in the northern hemisphere since accurate record keeping began in the 1960s.

All time top 25 Northern hemisphere snowfall rankings for the Nov-Apr period, notice how this year is first place, and also look at how 4 out of of my top 5 hurricane analog years of 1960, 1969, 1979, 2004, and 2010 are among the years listed below as being very snowy in the Nov-Apr time period. You can also see there are a few other interesting years to note including 1985 (#3) (holds the record for most hurricane landfalls on the US coast in a single hurricane season, 2003, 1996 that has been mentioned several times in many of my previous posts as being somewhat reminiscent of the current pattern, (a year that later featured hurricanes Bertha & Fran), 2004, & 2005 towards the bottom of the list.



Consider the fact that snow, in comparison to an environment with a lack of snow reflects 85-90% of incoming solar radiation, thus cooling the atmosphere, and in the fall & winter, even into the spring to some extent, colder air, taking up less space with the same amount of air molecules (making it denser than warm air), helps to force a contraction of the layer of atmosphere in the lower troposphere, which gives an opportunity for the upper troposphere and the stratosphere to expand, which is characteristic of warmer air that is more freely to move about, and such a condition helps to lead to stratospheric warming events, which are known to be associated with abnormally cool spells of air originating from the arctic, which under the right conditions, can be forced into North America and the US. In the summer, the conditions in place are different as the wavelengths of energy are much stronger, and force the natural jet stream to become much weaker and retreat in the summertime, forcing the natural weather patterns as well to shift northward in response to this. Thus, with a stronger than normal snowpack going into the summer, the effects are the opposite compared to the winter as the polar jet stream is much weaker and confined to the pole, which means that only regions of the arctic in the summer have significant snow cover. Thus, when snowpack in the spring is above normal in the northern hemisphere, (like what is being observed this year), this means only regions of the arctic experience the effects of increased snowfall, and due to the strong temperature gradient near the southern extent of the snowpack, this forces a bundling of cold air in the arctic, thus, cyclonic energy is induced, which is indicative of lower than normal pressures. Thus, when you have lower than normal pressures in the arctic compared to normal against the mid-latitudes, this helps to tighten the pressure gradient between the mid-latitudes and the arctic, thus inducing a +NAO.

Here is the correlation of summer NAO to 500 mb heights over the Atlantic, and to no surprise, if you have lower than normal pressures towards the Greenland & Canadian Arctic, this helps to strengthen the Azores-Bermuda high, which is the main steering mechanism for tropical cyclones in the Atlantic, thus with a stronger than normal Azores-Bermuda high thanks to a +NAO in the summer, this naturally forces storms farther west, closer to the US coast, and with this region of high pressure in the mid-latitudes, this also helps to promote lower than normal pressures towards the tropical Atlantic, helping to enhance hurricane activity (in a general sense).




North America summer temperature composite of the top 20 northern hemisphere snowpack years (excluding this year due to the fact that data has yet to be attained) for the Nov-Apr period reveals this increased snowpack in the spring having lingering effects into the summer pattern over the northern hemisphere, with colder than normal temperatures (shown in blues and purples) noted in the Canadian & Greenland Arctic.


At 500 millibars, the pattern reveals that due to the abnormally high spring snowpack, the resulting pattern in the summer during the hurricane season features a gyre of low pressure centered near the Hudson Bay and north-central Canada, with a resulting ridge towards Atlantic Canada, extending its influence into the northeastern US.


Look at just how close this is to my hurricane analog package 500 mb pattern released way back in March, with features like the “Hudson Bay Gyre” and the block of high pressure near Atlantic Canada notable features.


It makes sense for a large region of low pressure to situate itself over the Hudson Bay given the conditions at hand, especially in considering the above normal snowpack over the northern hemisphere, which was still above normal even into spring, somewhat different than the past several years.


April northern hemisphere snowfall anomaly



Those following summers with higher than normal snowpack in the northern hemisphere looked like this, (a lot like my summer forecast back in April), with below normal temperatures over the southeastern US, warmer than normal towards the northeast & New England, and warmer from the Rockies and points westward, with the plains, although possibly warm because of the cold PDO, it’s not as bad as last year.



The precipitation in those summers (blue above normal, purple well above normal, yellows and oranges below normal precipitation) seems to reflect some of the main ideas in my summer precipitation forecast that I released back in April, with wetter than normal towards the southeast, potentially drier towards the plains (although not as bad as the last few years), with hints towards drier than normal conditions and at least comparatively drier conditions to the surrounding environment in areas of the northeast and from the Rockies and areas westward.


Of course, if conditions are wetter than normal in the southeast, this is an indication of a few things. First of all, those of you living in the southeast, you often experience drought, however, in the summer comes the threat of tropical cyclones, and during those summers that you experience tropical cyclones, there are usually significant flooding problems. Yet, over a 10 year period for instance, 2 or 3 summers may have tropical cyclones, while all the others have none, well, the “normal” over this period of 10 years favoring or not favoring a tropical cyclone, favors a pattern without a tropical cyclone as 7 or 8 years (hypothetically speaking) do not have a tropical cyclone. Yet, in those 7 or 8 years without a tropical cyclone, drought is observed, but why? Well, “average” in of itself is just an average between two extremes drought and flooding rain, and when you have just a few tropical cyclones over a decade or so, the rainfall produced by those storms is so significant that it drives up the average several inches against the years, thus these tropical cyclones jack up the precipitation average well above the point where it would be in a “normal” pattern, thus in the southeastern US, it’s usually a feast or famine scenario when it comes to precipitation over the summer, rather than being in between. Thus, when I see in the analog patterns given the conditions at hand and other forecasts hinting at wetter than normal conditions over the southeast, there’s plenty of reason to be concerned.

Let’s take for example some years that featured an influx of tropical cyclones over the southeast US and look at those summer patterns.

1960 (one of my hurricane analogs)

Summer precipitation anomaly, overall near to slightly above normal in the southeast, note the above normal anomalies up the east coast, thus you can probably associate these precipitation anomalies with Hurricane Donna.


1960 hurricane season



1964 precipitation anomaly, notably wet towards Georgia, South Carolina, and north Florida.


To no surprise, those areas that were wetter than normal in the southeast were the same regions that experienced major tropical activity.

1964 hurricane season, note the congregation of storms in areas where it was wettest.



1979, another one of my hurricane season analogs, look at its precipitation anomaly, wetter than normal over the southeast


1979 storm tracks



1985 precipitation anomaly, once again showing, although not nearly as conclusive as the other years shown, wetter than normal conditions over the southeast, with regions of focus towards the immediate east coast and the northern Gulf coast.


The 1985 hurricane season, showing a collection of tropical cyclones towards the Gulf Coast and Hurricane Gloria up the US east coast, thus I think you can see a reoccurring theme here, where it is wettest over the US coast, (especially the southeast) is where tropical cyclones tend to be, and this essentially is common sense given that tropical systems are notorious for dumping large amounts of rainfall over areas affected by the storm.



Considering the cold AMO, a blend of the 1989 & 1991 summers gives you this precipitation wise over the US, notably wetter than normal over the southern US.


Those following hurricane seasons, to no one’s surprise were active on the US coast with hurricanes Hugo and Bob on the east coast.

Hurricane Hugo (1989)



Hurricane Bob (1991)



Also, let’s not forget the sunspot cycle to US hurricane landfall connection that I made in of my earlier posts, as it should come to no surprise, despite the cold AMO that these major storms struck when they did, at the peak of the solar cycle.

The picture below showing solar cycle 22, with the corresponding numbers at the bottom of the image indicating the date (yr then month from bottom to top), showing the solar cycle, a “double-peak” with one peak in 1989, the other in 1991, both years which featured a major tropical system on the US coast. (despite the cold AMO which usually does not favor US hurricane landfalls)



1995 summer precipitation anomalies, although near normal mostly everywhere due in part to the warm AMO flip, a few hints at slightly above normal precipitation over the southeast are shown with some regions of blue showing up.


1995 hurricane season



1996 summer precipitation anomalies, two distinct regions of heavy precipitation noted, one band towards the Carolinas & Mid-Atlantic, the other towards the western Gulf of Mexico & southern Plains


1996 hurricane season, with notable storms like Bertha & Fran hitting the Carolinas, although in this instance, the wetter than normal conditions over the western Gulf and the southern plains are not associated with tropical activity.



2002 summer precip, notice the shift farther to the south towards the Gulf of Mexico, with drier conditions towards the Carolinas


2002 hurricane season showing how the congregation of storms towards the Gulf of Mexico help to lead to the anomalously wetter than normal conditions over that area.



2004, a hurricane season analog, showing a large region of considerably wetter than normal conditions, the core of wet towards Florida, exactly where the barrage of hurricnes struck, and the wet conditions were not just over the southeast, but extending well northward into much of the eastern US.


To no surprise, with wetter than normal conditions in the summer, the culprit, a large number of tropical cyclones.



2008 summer precipitation, although not wet everywhere, it is wet towards the western Gulf areas that were affected by Ike & Gustav and its not quite as dry towards the Carolinas where tropical storm Hanna hit, but in between towards South Carolina, Georgia, and much of Tennessee, its drier than normal.


The 2008 hurricane season tracks help to reflect the summer precipitation pattern over the south



The composite of all of these active hurricane years on the US coast strongly supports the idea that increased tropical cyclone activity leads to above normal precipitation over the south.


Look at how close this is to my analog hurricane years of 1960, 1969, 1979, 2004, and 2010


Those summers with higher tropical activity that led to above normal precipitation overwhelmingly had cooler than normal summers, especially over the southern US.



In this type of pattern in the summer it will usually be colder than normal, (unlike the past several years), due to the fact that the increased amounts of water with its heat content being one of the highest of any substances known to man, helps to regulate temperatures in the surrounding environment, thus in the summer, as the sun angle becomes anomalously high and more radiation is received to earth’s surface, the water having a higher heat capacity has the ability to absorb similar amounts of energy without changing temperatures drastically, thus, significant heat waves are reduced dramatically under such a pattern (which in this case includes the southeastern US), and this is exactly why I have the southeastern US colder than normal this summer.

As mentioned earlier in this post, this increased snowpack in the summer has the opposite effect as opposed to the summer, in that it helps to enhance the natural temperature gradient between the mid-latitudes and the polar regions, and considering that colder air, due to the limited movement of the air particles in comparison to warmer air induces a sinking motion in the atmosphere, thus enhancing regions of high pressure. Also, knowing that air naturally flows from regions of higher to lower pressure, much like the biological process of osmosis, this time involving the movement of air particles from a higher to a lower concentration, this means air will naturally spiral inwards (due to Coriolis Effect) towards the region of low pressure directly to the south of the region of higher snowpack, this usually is an indication for low pressure just south of the Arctic, exactly where my hurricane analog package and the high northern hemisphere snowfall years have been putting an area of low pressure.


Now, when you look at the CFSv2 forecast for the summer, you can see it is beginning to pick up on a region of colder than normal temperatures (in blue), (implying for below normal pressures as well, which means a +NAO) over Greenland and the Canadian Arctic.



Another depiction of this cold over Greenland & northern Canada, this time from a global perspective.



Already since April, due to the abnormally high snowpack in the northern hemisphere, temperatures and pressures have fallen to below normal levels over the arctic, potentially offering as a precursor to what the summer may hold.

500 mb heights for over the last month, and you can see how the cold over northern Canada & Greenland correlates to the increased snowpack, and you can also begin to see the pattern seems to be revealing itself for what the summer may hold with a ridge over the north Pacific, (classic under cold PDOs) a trough over the central US (a good reason why I am forecasting a much wetter & cooler summer than last year there) and a ridge beginning to balloon over Atlantic Canada and in the northeastern US, which of course are also features evident in my hurricane analog forecast that was issued way back in March (even ahead of weatherbell).compday.


North American temperature anomalies over the last month



Of course, a +NAO usually results in more sea ice as cold air is bundled up over the arctic, helping to slow the rate of melting, leading to generally more arctic sea ice (although there are always exceptions from time to time), thus when I see sea ice forecasts from the CFSv2 indicating the next minimum to be between 5-6 million square kilometers, closer to the mid 2000s average, (much higher than last year’s minimum that fell below 4 million square kilometers.), this is giving me an indication that the NAO will be weighted towards its positive state this summer, which of course, given the information above, spells big trouble in accordance to US hurricane landfalls.

CFSv2 summer minimum sea ice extent forecast



JAXA sea ice & 1980s, 1990s, and 2000s, mean sea ice.



Upon looking at arctic sea ice and comparing it to oceanic heat content temperature anomalies for the top 700 meters of the ocean surface, I discover something that furthers my thinking that looking and focusing on the ocean rather than the atmosphere is a much better way to go when trying to look at arctic sea ice.

Let’s just remember, the energy budget of the oceans in comparison to the atmosphere is at a magnitude of 1100x, in favor of the oceans.

Heat Capacity of air & Ocean


One should not be too terribly surprised with the recent arctic sea ice declines as the AMO  entered its warm phase in 1995, and has been on an overall upward trend in oceanic heat content over the north Atlantic since that time, although it has appeared to have peaked in 2007, and the AMO may be on its way towards its cold phase.


Of course, the AMO beginning to head towards its cold phase has major implications on the overall pattern in the next several years, many implications which I have mentioned in my previous post from April 21st, one of the most significant being the major shift in hurricane tracks from the east coast to the Gulf of Mexico as the pattern at 500 millibars shifts in a general west-southwestard motion in response to the cooling Atlantic. With the colder than normal Atlantic and Pacific under a cold PDO, cold AMO pattern like what was observed in the 1960s & 70s, this argues for more activity towards the Gulf of Mexico because with both oceans being colder than normal in the deep tropics, this helps to enforce higher than normal pressures, and is a contributing factor to colder than normal temperatures at the 400 millibar level in the tropics, which is not favorable for tropical activity. The reason is due to the fact that tropical systems rely on the release of latent heat energy, which involves condensation, or the process of water vapor turning into liquid water, an exothermic reaction, which releases heat in order to compensate for the change in the overall movement of air molecules that is slowed under this process. The release of heat allows for further evaporation from the ocean surface, thus the process of latent heat energy release is enhanced, and along with the Coriolis Effect as well as the differences in the coefficient between the ocean surface and the higher levels of the atmosphere, helps to force air to spiral inward around a common center, forcing surface pressures to fall and more latent heat to be released in the process.

Speaking of 400 millibar temperatures, look at what has been observed thus far, clearly a favorable pattern for tropical cyclones with cold in the mid-latitudes, enhancing higher than normal pressures there, which help to focus convergence over the tropics underneath the already warmer than normal temperatures at 400 millibars.

Observed 400 millibar temperatures Jan-Apr 2013


Look at just how close this is to my analog hurricane season package of 1960, 1969, 1979, 2004, and 2010 for the exact same time period.


Certainly is not last year when it was colder than normal at 400 millibars in the deep tropics, a very good reason why despite the active African Wave train, there was a lack of activity in the deep tropics.

Last year’s 400 millibar temps


2012 hurricane season



Also remember that as temperature increases, the amount of energy difference between each degree increment is also greater, thus a larger energy exchange is observed in the tropics as opposed to regions of the poles, and combine this with the fact that the oceans have 1100x the energy capacity of the atmosphere, this effect of greater energy differential in the tropics is only enhanced by the oceans, this has effects on the 1950s-1960s observed pattern change between states of the AMO and its relation to the cold PDO, a relationship that is already beginning to show itself once again.

Hurricane Tracking Chart



Going back to the difference between the 1950s and the 1960s in terms of the pattern of storm tracks in the Atlantic, (which is an indication of where our current pattern will be headed as the AMO begins to cool over the next several years) clearly shows that there is a major shift in the zone of focused low pressures from the African Coast and the deep tropical Atlantic towards the Caribbean. Such a shift in the focusing of tropical energy has major implications on where storms are likely to go as evidence strongly supports in a general sense that storms in the Caribbean are more likely to impact the Gulf of Mexico and the classic “Cape Verde” storms more likely to strike the east coast.

This picture below helps to illustrate this concept, described above where storms in the Caribbean are more likely to affect the Gulf of Mexico (indicated by positive values and contours), whereas storms near the African coast and the eastern Atlantic, the east coast (indicated by negative values & contours).

FL vs E Coast Hurricane neutral yrs


More reason to be concerned about this year for the east coast is that the predictions for neutral ENSO based on the fact that another year of la nina will be difficult to come by given the multiple years of la nina already observed, and an el nino given the cold PDO signature in the North Pacific helping to force cooler waters into the equatorial Pacific, reducing the chances for el nino. When you compare east coast & Florida hurricane tracks from la nina years (like what’s been observed the last several years) and compare them to neutral ENSO years like what’s being forecasted, the one notable difference is the fact that the storms in a neutral ENSO pattern tend to come farther inland as opposed to la nina years. This is exactly why I am concerned about this hurricane season, in the fact that it being a neutral ENSO year and with the pattern of warm AMO, cold PDO like what was observed in the 1950s & 1890s, means that whatever storm systems attempt to hit the US east coast this year, unlike the last several years with Sandy, Irene, and Earl in 2010, will more than likely affect areas much farther inland as opposed to primarily coastal areas, thus, putting not just the coast, but much of the eastern US under the threat of significant tropical cyclones this season.


La nina east coast hurricane tracks

E Coast Hurricane Map La nina yrs


Neutral ENSO US east coast hurricane tracks

E Coast Hurricane map Neutral yrs


La nina Florida hurricane tracks

FL Hurricane Map La nina yrs


Neutral ENSO Florida hurricane tracks

FL Hurricane Map Neutral yrs


You can see the shift westward evident in overall storm tracks not just for individual seasons, but between the 1950s & 60s, as the PDO, although still cold, has a much better opportunity to result in el ninos, because during the 1950s, with the Atlantic Ocean warmer in relation to the Pacific, this forces that ocean to remain its cold state, (la ninas), however, when the Atlantic cools down, this helps to “even the playing field” between the two oceans, inducing more neutral & warm ENSO years, which as was shown in the comparison of the two pictures above showing major storm tracks between la nina & ENSO neutral years, in which, ENSO neutral conditions usually result in storms moving farther west, which is exactly what happened in the 1960s after the east coast barrage in the 1950s.

1950s US Major hurricane hits

1950s Major Hurricanes US coast


1960s US Major hurricane hits

1960s Major Hurricanes US coast


Also, another consequence of a cool AMO is the drought in the plains diminishes, while the winters in the US generally get much colder & snowier.

1950s winters


1960s winters

NESIS snowstorms by decade

You can even see some resemblance beginning to show up in the European winter pattern, very comparable to the early 1960s, before the flip to cold AMO


Europe winter temperatures last 5 winters


Europe winter temperatures winters 1960-1963


Look at this from a previous post, showing the relationship between the AMO & sunspot cycles, with lower sunspot cycles over the last several years beginning to coincide with an cooling (but still quite warm) AMO like what was observed in the early 1960s before the AMO crashed into its cold phase in 1965.

sunspot cycles since 1880



Oceanic heat content top 700 meters of the north Atlantic since the beginning of the reliable satellite record, revealing the substantial increase in ocean temperatures from 1995-2007, coinciding with a major fallout in arctic sea ice.

NODC NorthAtlanticOceanicHeatContent0-700mSince1979 With37monthRunningAverage



Northern hemisphere sea ice since 1979, notably dropped from 1995-2007, but since the time when the top 700 meters of ocean in the north Atlantic peaked in temperature, arctic sea ice has declined not quite at the rate observed in the early 2000s under a warming AMO, and a relatively warm (but cooling) PDO.



A map of arctic sea ice at the current time reveals the oceanic relationship to the cycles of AMO & PDO, with of course the Pacific side of the arctic towards Alaska, under a relatively cooler oceanic cycle of a -PDO, is observing near to above normal sea ice. However, since the fact that a much larger region of the arctic is open to the north Atlantic, this means the AMO has a greater effect on sea ice, especially towards the North American & European sides of the arctic, where the greatest region of sea ice loss compared to normal is currently being observed, as it would make sense given the AMO is in its warm mode.



I don’t usually like to focus on computer models, as it is not what I believe makes a great forecaster, rather looking at the conditions at hand and then making a forecast, using the models only as a guide or a tool to help give minor forecast adjustments here or there. That being said, I have begun to fall in love with the CFSv2, as it has proven to be unusually accurate of late in “sniffing-out” patterns before most other climate models. Take for example last December when everyone was concerned that this winter would be just like last year, and many thought I was completely nuts for claiming that winter would make a comeback later in the month, and not only that, but in my post on December 3rd I made a very bold and specific prediction on my white Christmas ideas for one to occur in areas east of the Rockies and south of the I-40 corridor. Here’s a quote from that post “Given all of this information, I’m going to go out on a limb and say that a majority of the US experiences a white christmas this year, (average is 33%), with someone east of the Rockies,(excluding the appalachians of NC & TN) and along and south of the I-40 corridor seeing a white christmas.”


This idea was heavily supported by the CFSv2, which seemed to pick up on this very early, despite some thinking that this winter was already over before it even started (lol).



Also, back in early January, after the brief period of cold in the US in late December, the CFSv2 for the Jan-Mar period, was predicting colder than normal conditions over the US, with the core of the cold towards the plains and southern Canada, and this certainly was a huge forecast win for the model. Meanwhile, other climate models like the ECMWF and the UKMET had absolutely no idea this was coming.



Actual temperatures, for the same time period, not bad eh?



Or even the late season cold, which lingered well into spring, the CFSv2 was “sniffing it out” well in advance, here is its forecast all the way back in December for the Feb-Apr period for North American temperatures.



Actual temperatures in North America for the same time period



In fact, look at the newly released NCDC temperature map, coldest April on record in the state of North Dakota, with it being top 5 and top 10 coldest throughout much of the midwest.



Meanwhile, other climate models like the ECMWF and the UKMET did not see this cold coming at all, and their forecasts busted big time in areas like Europe, and it would seem to me that models like the ECMWF and the UKMET have a significant amount of difficulty picking up on upcoming cold, while the CFSv2 appears to do fine. The issue may not be the climate model itself, but the parameters built into the model, like if it was to assume that constantly rising CO2 would equate to warming, and it is not occurring, then there’s a huge problem there, and the ECMWF does seem to be struggling immensely with the upcoming hurricane season, although that may be a combination of this and the oncoming neutral ENSO.

The ECMWF’s forecast for MSLP or atmospheric pressures, with shades of blue indicative of lower than normal pressures (rising motion), which is favorable for tropical cyclones, while areas of red are indicative of higher than normal pressures, which of course is not favorable for tropical cyclones.


Meanwhile, the CFSv2, although not very conclusive overall in indicating a very active hurricane season, there is some evidence
The CFSv2 giving some hints at a very active landfalling season on the US coast, with rains towards the southeastern US, that not only offer further support for my ideas that the summer will be cooler than normal there, but this is something that was referenced to years like 1960, 1964, 1979, 1985, 1989, 1991, 1996, 2002, 2004, and 2008


Now look at the forecasted ACE index of the CFS, in its latest 20 runs, and take note of the bright colors showing up in a band extending from the west coast of Africa to near the US east coast, this is indicative of the model keying on on this area as a region for abnormally high tropical activity. Also, when you have higher than normal tropical activity over a particular region, the release of latent heat and increased thunderstorm activity from the tropical cyclones would mean that the overall surface pressures, in a general sense should be lower than normal in this area as well. However, this forecast should be taken with some grain of salt as the CFSv2 forecast is based off of the GFS a few years ago, (which even to some extent today) has a very definitive poleward bias for storms, meaning that it has a tendency to force storms too quickly into the mid-latitude westerlies, thus its storm track predictions were often too far north & east, and if this is taken into account, this would give us the impression that the actual main storm track should be farther to the south & west of where the CFSv2 currently has it.


Compare this to the 500 millibar heights in my hurricane season analog package of 1969, 1979, 2004, 1960, and 2010 released all the way back in March (even before weatherbell), and look at just how closely (almost scary) in how this resembles the CFSv2 forecast above, as it seems some of the models are finally beginning to catch onto my ideas.


Others seem to be finally catching onto my summer temperature & precipitation forecast, shown below, which was released back on April 21st, looks very close to the forecast released later by Accuweather.

Accuweather summer precip forecast



My summer precipitation forecast from April 21

Summer precip forecast


Accuweather summer temperature forecast



My summer temperature forecast from April 21st

Summer temp forecast


Also, with an active US hurricane landfalling season, as was shown in my previous post, those years tend to be followed by cold starts to the following winter, particularly December. Here is the composite of the most active US landfalling hurricane seasons and the resulting temperatures in those following Decembers, which indicated by the shades of blue, is colder than normal over the eastern US.


This temperature composite image above based off of the active hurricane landfalling seasons being followed by colder than normal Decembers in the eastern US, and warmer towards the west was the premise for my forecast for the “start” of next winter, not the winter in its entirety.

start of winter


The CFSv2, which has proven itself of late in being a reliable climate model is sniffing out this cold start to next winter, as I’ve been talking about for quite some time now, with a cold signature developing over North America, seems as if the start to next winter may finish off where this winter left off.



About Eric

Hello, my name is Eric and I have had a strong passion for weather ever since I was very little, and over the last few years I've begun to research and really understand what drives the weather and have began to try my hand at forecasting. I personally love to track winter storms and hurricanes because of all of the uncertainty involved and the major implications that follow with the forecast. I am a very big snow lover and winter is my favorite time of the year, plus it's also hockey season for me (Go Hurricanes!). I really enjoy everyone's forecast and insight, and I enjoy answering questions anyone has about weather or weather related topics.

34 comments on “Verification of hurricane predictions

  1. Very Nice post, Eric! I enjoy reading your posts so much, especially when I see my own outlooks in them 😉
    Just a quick question…why did you name my outlook “Occupyweather’s” outlook instead of “US Weather Plus’s” outlook? Otherwise, great job, and don’t forget to check my 3rd summer forecast on my site and my youtube channel.

  2. @ Mark
    Thank you, and yeah I don’t know why, but for some reason when I saw your picture, it came up as “Occupyweather”, very strange, but I will check out your summer forecast when I get the chance. As you can probably tell, I really did try to make this post a lot shorter than the last few, and I honestly could have easily doubled the size of this post, but chose not to and will wait a little later to post some of that other information, especially regarding some tropical trouble that will be brewing towards the end of May and beginning of June thanks to the MJO moving towards the Atlantic and eastern Pacific. Tropical Storm Alvin in the eastern Pacific is evidence of this eastward propagation that is already taking place with the MJO.

  3. Thank you for this, Eric. Very good backing up your facts for your forecast. I could see you also as of now are predicting a cold and snowy winter for the east just like me.

  4. checking in and saying hi eric , tom m here and i truly appreciate youre dedication and intelligence in weather knowledge and i hope someday you can get a website similar to weatherbell old furum and you do daily post and eliminate loons with pay service for im there, latest is jacattack got a warning, you are beyond extreme intelligent and it goes beyond weather, it goes to solar and telleconnections and mjo and volcanoes but extreme computer intelligence as well , i can sit here and say i think plains be hot this summer but i respect every ounce of weather knowledge u print out ;;; down road , im there , old weather bell forum , pay , good , night and god bless ,and 3 scandalls ,, bye bye mr ob

  5. So, I was looking in the Farmer’s Almanac a few times over the last 2 months. They prediect somewhere in June 4th to June 7th there will maybe be our first 2013 Tropical Storm developing in the Gulf of Mexico. Do you think we’ll have any tropical activities happening during or around that time?

  6. @all bloggers
    I don’t know if any of you have seen this, but this guy, Levi Cowan, is honestly one of the best when it comes to tropical forecasting, and you really have to check out his forecasts & videos, so much to learn from him. Also, it is thanks to him in one of his responses to one of my comments where I talked about sunspot cycles & hurricane landfalls, and he essentially tried to discredit that, it is the reason why I went back and actually looked at all of the data since 1880 for US hurricane landfalls and compared them to the solar cycle and was able to find a very interesting correlation, and then I went back and compared this to the highest hurricane landfalling years since 1947, and that’s how I came up with the “common denominator” per say that all of these deadly patterns usually featured a +NAO, somewhat contrary to popular thinking that -NAOs are producers of significant hurricane landfalls. It was from here that I watched his video and saw that CFSv2 forecast for colder than normal temperatures over the Canadian and Greenland Arctic this summer and put together with earlier forecasts I saw in regards to sea ice, which was projected to be slightly higher than the last few years, closer to the mid 2000s average, that I was able to get the idea for a +NAO this summer, and that’s because +NAOs naturally like to bundle cold air over the arctic, thus sea ice is usually kept in check and cold air is held over the arctic, making those areas towards Greenland & northern Canada cooler, which is exactly what is being observed in much of the climate modeling. This idea for +NAO this summer is even further supported by the higher than normal snowpack over the northern hemisphere in the month of April, and of course also in my hurricane analog 500mb package that was released all the way back in March (in that extremely large post), even ahead of weatherbell (which claims they were first). Thus, with a +NAO, this tends to strengthen the high to the south over southern Canada and Atlantic Canada, and with the cold PDO, this helps to induce a trough of low pressures near the western US, a -PNA, which is also supported by recent increases in solar activity, that I have shown in the past has an inverse correlation to the PNA, so it would make sense to see a trough there. With a trough near the west coast, this will help to pump the heights to the east over southern Canada and Atlantic Canada, and when you have a strong area of high pressure blocking there, as you have probably seen many times, this is closely associated with high numbers of hurricane landfalls, and with the pattern of cold PDO & warm AMO like what was seen in the 1950s and & 1890s, when the east coast got hit with a barrage of major hurricanes, you can probably see why I’m worried this year about the east coast, to not just get hit once, but perhaps multiple times.
    Here’s the link to the site with Levi Cowan, you have got to check out his videos, and all of the very cool model graphics he’s made, I will probably use some of these tools over the coming hurricane season.

  7. Hey Eric! Long time no talk:-) ..hope everything’s been good with you. I’ve been really busy at work but was looking forward to ur summer hurricane blog…I see you didn’t disappoint! As always very informative and excellent in ur displays! Learned so much from you last winter and made me eat my words more than once with the winter forecast! Its all good..I see ur predicting a active and possibly bad hurricane season for us here on the eastcoast. This is one time I hope ur wrong! Eastcoast was beat up pretty good last year…lost of damage n fatalities.. hope it doesn’t come to pass. But knowing ur rep so far…doesn’t look good us. Stay good and we’ll talk later…peace..

  8. @All bloggers

    I found this site courtesy of the University of Illinois, and it is full of absolutely great information and below, in case you don’t understand some of the processes I mentioned above in my post and previous ones or need to “touch up” on some other areas, here are the links to some very important atmospheric processes, and even me who does know a lot about the weather have learned a few things in reading some of these posts.
    Just in case, I know these pages may be hard to follow at times, I posted all the links to all of the pages just for all of you.

    Here’s the main page, “Meteorology Guide:Online Guide”

    Here’s the main page to “Light and Optics”

    “Reflection of Light”

    “Scattering of Light”

    “Refraction of Light”

    “Refraction of Light 2”

    “Diffraction of Light”


    “Halos (22 degrees)”

    “Halos (46 degrees)”


    “Sun Pillars”


    “Blue Skies and Blue Haze”

    “Crepuscular Rays”

    “Silver Lining & Cloud Iridescence”

    “Air Masses and Fronts”

    “Air Masses”

    “Maritime Tropical Air masses”

    “Interpreting Surface Observation Symbols”

    “Observed Weather Symbols”

    “Observed Dew Point Temperature”

    “Observed Cloud Cover”

    “Observed Sea Level Pressure”

    “Observed Winds”

    “Surface Contours”




    “Wind Direction and Isobars”


    “Radar Meteorology”

    “Sending & Receiving Signals”

    “Scattering of a Radar Pulse”

    “WSR-88D Radar Imagery”

    “Hail Reflectivities”

    “Interpreting Doppler Radar Velocities”

    “Locating A Target”

    “Scanning Modes”

    “Radial Velocity”

    “Phase Shift”


    “Locating Tornadoes”

    “Interpreting Radar Velocities”

    “Hurricanes on Radar”

    “Short-term Forecasting”

    “Flash Floods”

    “Snow Storms”

    “Interpreting Radar Velocities 2”

    “GOES Satellites”

    “Polar Orbiting Satellites” (interestingly, it was thanks to these satellites that many of the computer models, especially the ECMWF, were able to hint at Hurricane Sandy coming farther to the west, and without these satellites, we may not have known the storm was going to hit the US, and would have more than likely seen solutions similar to that of the GFS, which was well out to sea with that storm into a “bowling-ball” low pressure system.)

    There are so many other things to explore on this website as well, with many other helpful slides to help any weather enthusiast (including myself) to become better at predicting, interpreting, and understanding the weather.

    This site also does “Case Studies” on certain historical events, and it is very interesting to look at as well, with Hurricane Andrew
    Veterans Day Snow 1996
    1993 Superstorm

  9. @midatlanticweather
    Oh you’re predicting a colder than normal winter too, if so can you post a link to your website or perhaps offer some of your thoughts on this, because it is usually the bloggers like you that help to ignite ideas in my head that helps me come up with ideas for upcoming posts. Anyway, thanks for commenting, greatly appreciated.

  10. @tom m
    Thanks as always, and that is very odd how weatherbell seems to be doing this to some of the best bloggers there, yet loons are left alone, but oh well. I do read your comments on the main forum and do find some of them interesting, and please keep those coming, because as I told midatlanticweather, many of the things I’ve learned over the years and new concepts I have applied to my forecasts and posts have come from blogger comments and concerns.

  11. @ Bradley Folsom and other bloggers interested in the potential tropical threat going towards the end of may-beginning of June
    That is actually a very good question, and although I am not aware of precisely how the farmer’s almanac comes up with their predictions (I know its some sort of “magic Formula” and if I know it has something to do with the 30 day sunspot cycles among other things, of course, this is also something you often see in many of my posts, and I rely heavily on the 30 day sunspot cycles to predict the PNA, which is a quadirpole pattern. (4 areas that are mainly affected, or 4 “poles” with pressures affected over the North Pacific, Northwestern North America, and the Southeastern US, with some effects on pressure pattern also observed over the Canadian Arctic and the equatorial Pacific)).

    I have been well aware for at least the last week or so that some sort of tropical disturbance should form in the Atlantic as the MJO, (which is essentially a 30-60 day westwardly-propagating wave of energy in the global tropics that helps to determine the amount of upward motion in the tropics, which is vital to thunderstorm activity that are the basis and building blocks for tropical cyclones.) should move its upward pulse towards the Atlantic, meaning that upward motion and thunderstorms will be favored in our part of the globe. In this case, what you will notice in the links to the models below is the MJO going into different “Octants”, from where it currently is over Octant 5, which is “Maritime Continent”, which is the area in between the Indian Ocean and the Western Pacific, and this area of “Maritime Continent” includes areas of southeastern Asia and Indonesia. For the MJO to be in the Atlantic, or favoring upward motion in the Atlantic, the MJO needs to get into Octants 8-2, (even 3 is favorable) with octant 8 centered over the eastern Pacific and Octant 1 directly over the Atlantic & Africa while Octants 2 & 3 deal with the Indian Ocean and the Indian Monsoonal Circulation, and of course during the heart of hurricane season, the MJO being over this area would have large effects on the hurricane activity in the Atlantic. Reason is of course, the origins of about 90% of all significant tropical cyclones in the Atlantic can have its origins drawn from African Waves that originate in the Ethiopian highlands over eastern Africa when air coming off the Indian Ocean from the Indian Monsoonal Circulation is forced to rise to the topography of this area, thus enforcing a phenomena that is known as “Orographic Lifting” where the natural topography and local geography of a certain area forces the air to rise, and in doing so, the air forced upwards into higher levels of the troposphere naturally cools, and as the air cools, carrying the same amount of moisture, the air will reach a point where moisture must be released, and this helps to form precipitation on the windward side of the mountains. However, unlike a typical pattern where the air descending down the other side of the mountain, dries out, this is not the case with Africa, as the natural difference in pressures and temperatures between the Sahara and the African Congo, help to induce wind shear, which helps to ignite the African easterly jet. This African easterly jet along with the natural northward movement of the ITCZ (InterTropical Convergence Zone) that is created by southeasterly trade winds from the south and northeasterly trade winds from the north that are created under the “Hadley Cell” and the Coriolis effect help to from these African easterly waves, and upon emerging in the Atlantic, these systems can then feed off of the warm tropical waters and convert their atmospheric processes to one that relies primarily on the release of latent heat energy (a process that is derived from condensation of water vapor to its liquid state, and in a reduction in the freedom of movement in the water molecules from the gaseous to liquid state energy is released in the form of heat to compensate for this reduced movement.) and from here can become tropical cyclones. So, when the peak of the hurricane season begins to approach, it will be very important to watch the position and strength of the MJO, because if it is strongly entrenched over the Atlantic, or over Africa, then, we will have to pay very close attention to any tropical activity, because under such a set-up with an upward MJO pulse in the middle of hurricane season, this spells major trouble in terms of tropical activity.

    Here’s the link to the MJO from NCEP
    Here’s the link to MJO from a multitude of models, from GFS, to UKMET to the ECMWF, among so many others to give you a better idea of where the MJO will be, and the reason I look at other models for the MJo, like the ECMWF for MJO, rather than the GFS is because the physical parameters that the GFS model is based on have a large amount of difficulty in handling tropical energy, and it is usually way too progressive (too fast with moving the MJO across the global tropics), and the ECMWF, although very good at handlingthe MJO, is known for being too slow in the “Maritime Continent” octants of the MJO, thus may be too slow with its progression, thus a compromise between the GFS & ECMWF is the most viable solution regarding the MJO at this point. Under these conditions, we should look for the MJO to move towards the Atlantic towards the end of May (generally from the 25th or so and later, and potentially stick around well into June, as the tropical Atlantic, in relation to other regions of the tropics, is warmest compared to normal, and knowing that the MJO is essentially an oscillation that measures vertical upward motion in the tropics, having the warmest waters in the Atlantic means that with the warmer water around, this induces upward motion because warm air surrounding the warm water will naturally have a tendency to rise in the presence of the warm water below, thus there is reason to believe that the warmer than normal waters over the deep tropical Atlantic will have influence on helping to promote the upward phase of the MJ), which induces tropical activity.

    Also, another factor that has to be taken into account is the PNA in relation to the sunspot cycles, which I mentioned above and have made note of in many of posts, in that it is important to understand the inverse correlation between the two with the 30 day sunspot cycles being the driver in pushing the PNA around in its respective states. Looking at the 30 day sunspot cycles at the current time, it is very important to note how they are extremely high, over 200 sunspots, which means that with rising cycles, the PNA should in essence go towards its negative state, which means a trough should form over the western US, and conditions will likely get much more stormy and active there over the coming days.
    30 day sunspot cycle

    PNA (notice recently how it has fallen negative in response to the 30 day sunspot cycles increasing, helping you to show the inverse correlation between the PNA & 30 day sunspot cycles)

    With a trough over the western US, this has implications in the long range pattern over the US, as a large region of low pressure there will help to pump atmospheric pressures and heights downstream of the pattern over the US, and considering the fact that since we are deep into May, and the solar wavelengths are very strong, the jet stream is naturally much weaker this time of the year, and the wavelengths of the jet stream between one trough and the the next ridge are much shorter in distance, meaning that with a major trough in the western US now as opposed to the winter time where a ridge would be promoted in the eastern US, this pattern will now force a ridge over the central US and into Canada. Knowing that when you have a ridge over central Canada this helps to promote tropical activity by air spreading out in all directions from the high pressure center helping to force convergence to the south, thus rising air, means conditions naturally become much more favorable for tropical cyclone formation. Another thing that I take note of is a trough will try to enforce itself over the eastern US, however, at this time of the year, because of the shortening jet stream wavelengths, such a trough can get cut-off from the main jet stream flow, and energy can get left behind in the form off a stalled frontal boundary, and these types of set-ups with stalled fronts into the Gulf are very notorious for resulting in tropical cyclones. Combine this with the upward pulse of the MJO that I talked about earlier in this comment, this means there is going to be a lot of upward motion over the Gulf of Mexico, Caribbean, and the Eastern Pacific, so regardless whether or not a tropical system forms, the pattern is going to get very stormy & wet over the southern US, Florida, and the Caribbean as May begins to come to a close and June begins. Also, with this set-up, we are likely to see the Columbian Monsoonal low become very active and as the MJO progresses from the eastern Pacific to the Atlantic, what may actually occur is we may see a storm system over the eastern Pacific take a very odd track coming from the southwest and hitting central America and then with whatever remnants and tropical energy are left over getting absorbed into the monsoonal low and the western Caribbean. Also, with the stalled frontal boundary, there is certainly reason to believe that we may see a “fujiwhara” between whatever disturbances form in this pattern with the upper level disturbance from the stalled front and the energy from the monsoon low merging and moving towards each other in a counter-clockwise motion around a common center. This kind of scenario means that whatever system gets going due to its monsoonal nature (like the storms that form in the western Pacific), will be very large in nature, and with a favorable environment generally in place, there will be concern that if conditions are right, this storm could potentially be large and powerful. However, trying to determine intensity and precise locations that will impacted is a pointless because of how far away we are from this event occurring.

    However, I will give you a few recent examples of this type of scenario to give you a general idea of what is going to unfold over the next few weeks.

    Arthur (2008)
    500 millibar pattern
    Notice the trough over the western US (-PNA) enforcing a ridge to form over southern Canada and the central US with a trough over the eastern US that does appear to get “stuck” underneath building pressures to its north, implying that a stalled front is in place and knowing that the MJO had its upward pulse over the Atlantic about this time and Arthur, although a short-lived tropical cyclone, was monsoonal in nature, which is exactly what I am thinking may occur in the upcoming potential system as we get towards late May and early June.

    Image of Arthur showing its monsoonal nature

    Track of Arthur

    Arlene (2005)
    Notice the similarity in the 500 millibar pattern (link below) to Arthur, cut-off low over the northwestern US, indicating a -PNA, ridge up the spine of the Rockies and central US into southern Canada with some sort of trough in the eastern US.
    Track of Arlene

    Alex (2010)
    Notice in this storm, the pattern is slightly different, although some sort of -PNA is noted with pressures slightly lower than the surrounding environment with a ridge over the southeastern US and a ridge over the Pacific, and of course the low pressure gyre (indicated by the shades of blue & purple) does seem to imply for some residual troughiness over the eastern US, like what was observed in Arthur & Arlene. of Alex

    It is also interesting to note how devastating 2005 & 2008 were in terms of tropical cyclone landfalls on the US with rememberable storms like Katrina, Rita, and Wilma in 2005, Fay, Gustav, Hanna, & Ike in 2008, and although 2010 was not particularly dangerous for the US, it needs to be considered that 2010 was a la nina year and Hurricane Earl, a category 4 hurricane almost hit the east coast, and once you consider the evidence I presented in this post above where I talked about how compared to la nina years, neutral ENSO years tend to see tropical systems coming farther west, there is further to be worried about this year along with information I’ve presented over the last few months in my other posts. In general, it is interesting to note the Farmer’s Almanac picking up on a potential tropical disturbance in the Gulf of Mexico during June, and the idea that the threat level for a tropical system during this time will increase given the conditions at hand, although it is too far out to determine where any potential system may go or impact, but regardless the pattern over the southern US, the Caribbean, and the Gulf of Mexico will get much more unsettled and flooding will be a concern.

  12. @ AutoFill Rob
    Hey, good to see you again, and yeah I honestly feel the same way you do, i really hope I’m wrong about this upcoming hurricane season, but given what I’ve observed over the last several months regarding the conditions at hand, things do not look good at all, and knowing that we are in a pattern similar to the 1890s & 1950s when a barrage of major hurricanes struck the US east coast, I’m definitely worried by the fact that we have yet to see any major hurricanes hit the east cast (although Irene & Sandy were significant, may not stack up to what this pattern may be capable of), and that something much stronger may be lurking for this year.

  13. @ Eric…that’s bad news for real! Even though I’m interested in hurricanes and there development the damage they do is crazy…and what you said about the mjo and the ridges sounds sooo similar to winter storms and how the mjo is responsible for the changes in weather and the pattern DURING the summer months also( sorry wasn’t aware of that)…continue to learn from u n the guys on here.. thanks!

  14. It’s almost June and it might snow in the northeast mountains wow that incredible and they are saying about global warming? I don’t think so lol

  15. Eric…Nice write up once again! And please just keep those canes away during the 3rd wk of Aug. as I will be at the beach…LOL

  16. @ Autofill Rob
    Yeah, of course the MJO has a large effect on the weather pattern year-round, however, during the period of time from mid-February to mid April, the NAO takes over as the dominant force in the pattern because of the rapidly changing jet stream wavelengths, which is caused by the changing axial tilt of earth and increased solar wavelengths. Now, why would the NAO have such a large effect with decreasing jet wavelengths? Well, if you really think about it the jet stream itself has the same number of wavelengths, including troughs and ridges in the spring and fall as it does in the winter, however, as the jet stream retreats towards the poles the radial distance across the northern hemisphere of the jet stream decreases, meaning that the same amount of troughs and ridges are enforced in a smaller amount of space, thus the distance between each one naturally would be smaller, however, some areas of the northern hemisphere respond much faster to changes in a retreating jet than others, for reasons like lack of snowpack, presence of a subtropical high, typically found near the “Horse Latitudes” (the region around 30 degrees north of south of the equator, where the Hadley Cell found over the tropics due to the fact that the maximum sun angle is found here, which induces warmer air that has a tendency to rise, and once this air hits the tropopause (the boundary between the troposphere & stratosphere), which is naturally higher in the tropics than at the poles, the air cools and over time it spreads out naturally in an anticyclonic motion in the upper troposphere, eventually cooling enough to sink back down towards the surface, and this sinking motion is usually found near the “Horse Latitudes” where the subtropical high pressure is found, and it is because of this interaction between the Hadley Cell and the subtropical high that many of the world’s deserts are found near 30- degrees north or south latitude. This high pressure though does not sit directly over the Horse Latitudes over the entire year, it migrates north and south in response to the changing jet stream, which varies in strength due to the variable solar wavelength, with it moving farther north in the summer and moving southward in the winter, at least for the northern hemisphere. This notable movement northward in the Azores-Bermuda high can be easily observed over the progression of the hurricane season, and will be interesting to watch over the next few months.

    As far as the MJO, if you really think about it, and this is something I have said many times that the difference in the amount of energy per degree increment in warmer temperatures is greater than that in cold temperatures, and also considering the fact that this effect is amplified by the oceans, which have 1100x the energy capacity of the atmosphere, thus when you put these two conditions together, warm tropical oceans, you get oscillations such as the ENSO index, MEI, equatorial kelvin waves, and the MJO that help to measure changes in the warm tropical oceans. The MJO, though and a 30-60 day tropical oscillation, specifically measures upward motion in the tropics over a relatively short time period in 8 octants, and looking at a much shorter time scale for measuring these very important tropical oscillations is important for predicting overall tropical activity on the scale of several days to a few weeks, and this will be something I will use in this upcoming hurricane season to try and predict active and inactive periods of activity.

  17. @ Derickeugeneree
    Yeah, I know, but I am not like the AGWers who scream just about every time an extreme weather event occurs and use it as evidence of AGW, however, this is interesting because the only way you can get snow this time of the year is with an unusually large amount of cold air supply, and this is strongly supported by the northern hemisphere snowpack, which broke a record for the Nov-Apr period for having the most snow since record keeping began in the mid 1960s, and since snow reflects 85-90% of solar radiation, naturally cooling the air, it would make sense that having more snow around would increase the amount of cold air available and make events like these more likely.

  18. @Reid
    Thank you, and yes I will be looking into trying to nail down some more specific time frames for tropical systems based on the MJO, and my analog years and I’ll make a new post sometime down the road analyzing my findings.

  19. Well Eric and others, it sure is nice to be back…have been busy with school and NJ ASK (standardized testing sux). I spent a while catching up…it doesn’t look good or me this year: oh nature, spare me and my poor state this year. Could New Jersey be wrecked again this year? It seems as though weather is getting wilder as the years go by. I am not fully convinced on global warming, but it does suggest that both extremes (hot/cold, wet/dry) would all be acheived, and they all have been or are being achieved. It is honestly scary. Any thoughts?

  20. @Mike D
    Hey, it’s good to see you again, and yeah I’ve had a lot of testing lately myself and that’s why my blogs and comment responses have been a little slower than usual. As far as the extremes go, no this has nothing to do with AGW, because weather itself is just a product of nature trying to balance out the natural imbalances created by the difference in heating as the earth’s axial tilt changes, the difference in the ratio of water to land in the northern and southern hemisphere, which means there is a larger absorption of heat in the southern hemisphere compared to the northern hemisphere because of the fact that water has 1100x the energy capacity of the atmosphere. Also, with increased water compared to land, temperatures in the southern hemisphere are much more stable than that of the northern hemisphere due to water vapor having one of the highest heat capacities known to man. Also, the lack of significant geographic features in the southern hemisphere is actually another reason why Antarctica is colder than the arctic, because of how the geographic features affect the stratosphere, and the Brewer-Dobson circulation (a factor I will talk about a little bit more in upcoming posts, and is something I am currently reading up on in some scientific papers.), because when air rushes over the mountains in the troposphere it is relatively compressed, however, once the air descends down the other side of the mountains (like the Himalayas or the North American Rockies) some of the air continues outward at the elevation it had to attain to go over the mountain, while other air particles go down the mountain towards the surface. What this does is air in the tropospheric column spreads out, and this spreading out of air leaves a relative gap on the “Leeward” side of the mountains which when you have air spreading out in all directions, that is indicative of warming, thus this warm air rises up into the upper troposphere eventually past the tropopause and into the lower stratosphere, where in this case, the stratosphere’s distribution of temperature being colder near the lower levels while warmer higher up means that much of this energy associated with the rising warm air created is forced to deposit its energy into the lower levels of the stratosphere, (this propagating wave of energy in the vertical vector is referred to as a Rossby Wave). However, in doing so, there is a belt of strong winds in the stratosphere known as the QBO, which has relation to the Brewer-Dobson Circulation and the stratospheric polar vortex. With a deposit of energy into the stratosphere, courtesy of the air flow being severely altered around the mountains, this slows down the natural winds in the stratosphere, even forcing them to reverse direction, and when airflow is slowed down going into the polar vortex (the polar vortex is created by the polar “night jet” which is formed when the reduction in sun angle, and complete darkness leads to a significant reduction in energy near the pole that grows stronger as the hemispheric winter wears on, and it is this difference in energy and temperature that creates wind, which is greatest along the line where day turns into night, and this wind that is created all the way up into the stratosphere helps to create the polar vortex, which is a vital part of the winter pattern), this weakens it to a point where splitting occurs into multiple vortices (known as ‘daughter cells’), displacement southward into the mid-latitudes, that usually results in unusually powerful arctic outbreaks or complete collapse which unleashes historically cold air into the mid-latitudes, and it is the destruction of the polar vortex that we call stratospheric warming events. In general, because of the lack of fairly significant geographical features in the southern hemisphere, this leads to a decreased risk in stratospheric warming there and means also that the polar vortex over antarctica is more organized, which also in turn leads to a much stronger supply of cold air in that region as well. Other imbalances created like precession or the variability in earth’s orbit created by the gravitational pull of the other surrounding planetary bodies in the solar system and variability in solar activity all leads to weather, and certain extremes. Given the fact that we are in a period of a cold PDO, warm AMO (both significant oceanic oscillations that have large effects in climate and with their cycles generally lasting 20-35 years or so), it is this clash between the warm Atlantic and the cooling Pacific that helps to spark these weather extremes, because with a cooling Pacific this leads to an increased supply over cold air over northwestern North America, while the warm AMO in place keeps a large influx of warm air into southeastern North America, acting as a resistor to changes occurring in the Pacific, and considering that under the “Ferrell Cell” of energy between the Hadley Cell and polar cell, weather moves west to east thanks to a deflection of energy by the Coriolis effect, and the continent that stands in between these two opposing oceans is North America, and it would make sense as to why extreme weather would be occurring here. Also, a lot of the extreme weather being observed today isn’t without precedent as we were in a similar pattern of warm AMO, cold PDO in the 1950s and 1890s that featured major east coast hurricanes, midwest drought, long winters, and of course an increase in tornadoes was also observed, all conditions we are seeing now.

  21. As always, your responses are full of information Eric.
    And I am unlucky (even though I dont believe in luck).
    Welcome Tropical Strom Andrea. Staff here at Weather Advance is incredible, in comparison to the comical face of Ridiculous!!! It’s only June and I’m getting a tropical storm…guess I won’t be having championship baseball on Saturday. Anyway, I wanted to hank you for all your time and effort to please commenters. Thanks Eric!

  22. @ Mike D
    Thank you so much, and it is because of commenters like you that I continue to grow as an aspiring meteorologist and I want to thank you and all of the other bloggers here for giving me feedback and asking any questions and concerns you have, I can’t stress enough how important you guys are, and even what may seem like the dumbest question, can actually seem extremely brilliant and lead me to discover and learn new things about the weather. Right now, I have printed off and saved a plethora of scientific papers, my posts, and other readings, as well as looking at other blogs, so this summer, I will push myself very hard to get even smarter and gain much more knowledge on the weather. If you have any questions or concerns, or even if you want some of the links to the scientific papers I’m reading so maybe you can see some of the research for yourself feel free to ask. I hope I can get a new post up soon, probably will make it shorter and to the point, but we all know how that turns out, lol.

  23. @ Mike D
    Ok, sure here are some of the things I’ll be reading through this summer
    These are a few of the scientific papers I’ll be looking at and other things. This is to just get you started, I’ll go try and find more, but I think these are definitely well worth the read, and if you can understand them, wow you’ll come out of them a much smarter individual and much more understanding of the weather, not just winter storms for example.

    Meteorology 101 american weather blogs

    Forecasting the March 12-14 1993 Superstorm (I think a lot of the winter weather gurus should definitely read up on this one)

    Forecasting strategies “world of weather”

    Oh yeah, don’t you remember the correlations and relationships I made to the solar cycles and US hurricane landfalls in an earlier post? Well, I’ve actually gone back and looked and there are several scientific papers that have supported my idea that the extremities of the solar cycle seem to correlate well with higher US hurricane landfalls. (link)

    Here are the links to the 2004 & 1969 hurricane seasons accounts & detailed analysis, well worth a read, and you may see some things in these papers happen once again this hurricane season, given the reliability of my top 5 hurricane season analogs.
    2004 hurricane season

    1969 hurricane season

    Here’s a new one I just found, and will print it out and read this over the summer, this one talks about hurricane processes like concentric eye walls, secondary wind maximum, and the evolution of the hurricane vortex itself, these are the kind of things I read about to get a better understanding of certain concepts and I put those concepts into my new posts. (link)

  24. I found this college-level book about meteorology, and it had quite a bit of information that I didn’t know about. I would recommend getting it.

    Name: Essentials of Meteorology An Invitation to the Atmosphere

    Author: C. Donald Ahrens

    Other notes: It is the fifth edition. Although some of it is very basic, much of it includes quite intricate aspects not covered by other books, articles, etc.

  25. @ Mike D
    Here’s some more, as a matter of fact, if you go onto google search and go to “even more” and search for scholarly papers, you will find an absolute gold mine of information, virtually endless scientific papers to expand your knowledge, what I have below is “just the tip of the iceberg” per say.
    “700 year sedimentary record of intense hurricane landfalls in southern New England”
    “On the Madden-Julian Oscillation & Atlantic Hurricane Relationship”

    A new one I just ran across, wow, a goldmine of information about tropical cyclones in here, “Global View of the Origin of Tropical Disturbances and Storms” (link)

    “Prediction Models for Annual US hurricane counts”

    “The Sun Defines the Climate”

    Brewer-Dobson Circulation and the Stratosphere, each separate link with its own information, all courtesy of Colorado State University, the same one that produces the famous hurricane season forecasts.

    “Using QBO to predict the number of hurricanes hitting the US”

    The Quasi-Biennial zonal wind Oscillation (QBO)

    “Atlantic Hurricane Frequency Part 1: El Nino and 30 mb Quasi-Biennial Oscillation Influences”

    “Connection between the Solar Cycle and QBO: The Missing Link”

    “The Effects of Space Weather on Hurricane Activity”

    Hope you enjoy these papers and links over the summer, going to make for great reading, especially on days where the weather is slow or perhaps you may be bored. I’m probably going to try and read through many of these papers multiple times so I not only understand them, but are able to interpret them and apply some of those same concepts to weather patterns and forecasts.

  26. @ Mike D
    Thanks for the heads-up, I’ll definitely look into that book,I did find a little tidbit of information from that book online, doesn’t seem too hard to understand like some of those scientific papers, so thanks a lot, I will definitely try and get that book. I hope you enjoy the links I posted, because there is A LOT of information in them, and I suggest either bookmarking those papers or maybe printing them out, (of course if you dont want to use up a bunch of paper printing may not be the option for you)

  27. Honestly, I am a recycler and paper-saver, but reading too much online can cause eye damage so…health is more important than some recycled pages. 🙂

  28. @ Mike D
    Yeah, I agree with you, and that’s probably a very good reason why my eyesight has gone very bad in the last few years as I stare at my computer screen virtually all day, lol, I should probably try to limit that. Speaking of which I have A LOT of paper I’ve printed out over the last 4 years of gathering weather information, with just within the last few weeks, I’ve printed out probably about 15 scientific papers. I’ve put everything into a binder, and just to give you an idea of how much information I have, I use 4 separate 1.5-2 inch binders full of paper just about weather, and a lot of that information I’m going to have to read this summer. This is probably one of the few times in my life I’ve actually looked forward to reading, lol.

  29. @ Mike D
    Lol, I’m with you on that, whenever I have the opportunity, I will try to do some reading. I also keep some of Joe Bastardi’s information that he posts on twitter, like for example, I printed out a post he did in forbes magazine, really cool, as it helps to give some general highlights on the pattern and give some historical precedence. Thank you anyways for the college textbook suggestion, I’m going to try and get it sometime in the future, as I’ll probably need it anyway when I study meteorology in college.

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