Feb 07 2013

Southern New England and parts of the northeast to get absolutely crushed by a crippling snowstorm Friday. Another system to follow towards Valentine’s Day as pattern becomes even more favorable

Hi all, sorry I have not posted in a while, but I do want to make this post much shorter than usual because of such a major storm we have at hand with major implications for the northeastern US. As I said all the way back in December, this worst of winter had yet to come, and based off of the northern hemisphere snowfall anomaly and the effects of the major stratospheric warming event still at hand, the worst of winter had yet to come and would be from late Jan-Feb. Many people had very doubts about this however, when one looks at what is actually happening, you can certainly see that the worst of winter is certainly upon us. Just look back at what we were dealing with in mid January with much of the US basking in well above normal temperatures and major snowmelt occurring nationwide.

Temperatures for the period roughly from the beginning of the 2nd week of January to about the 20th looked like this, with warm across the east, but very cold conditions across the intermountain west and into the southwestern US.

Here are the temperatures for January 6-19 of this past January, clearly can see conditions were indeed warmer than normal over the eastern US, although the same could not be said for the western US.

Now, many people thought at this point winter was over and spring was just around the corner, but did they even acknowledge that the great winter of 2009-10 also featured a formidable warm-up during the heart of winter, but most of that was soon forgotten by “snowmaggedon” that soon followed. Interestingly, you also notice that the warm-up in 2009-10 was much more widespread over the US, rather than what was observed this year with the warm-up being mainly confined to the east and central US while areas from the Rockies and points westward shivered.

Here are the temperatures for January 14-January 25th 2010, you can clearly see there was a very significant period of warmth in the heart of that great winter of 2009-10, of course many people seem to forget this because of what soon followed.

Now, many people tried to say this was like last year, but as I explained in my last post, this winter has turned out be to nothing like last year, a simple temperature and snowfall comparison shows reality.

Temperatures for the first half of last winter looked like this, blowtorch warm over much of the US, only exception being towards the southwestern US, especially near west Texas, where they received a rare white Christmas even into El Paso, TX.

The temperature anomalies for last winter from the beginning of December through mid-January, and you can see significantly warmer as a whole over the US, especially over the plains, but thanks to the a rare white Christmas for the southwestern US, notice how it is actually cooler than normal over SW texas and New Mexico because of this.

The temperature anomalies for last winter from the beginning of December through mid-January, you can see significantly warmer as a whole over the US, especially over the plains, but thanks to the a rare white Christmas for the southwestern US, notice how it is actually cooler than normal over SW texas and New Mexico because of this.

This year through mid January for roughly the same time period shows it is overall much cooler for the US

Here is the temperature anomaly for this winter through mid January, you can see as a whole, much cooler over the US, especially for the Plains and there’s more pronounced cooling over the western US as well.

However, it could have been much worse than last year, take the winter of 2006-07 for example with even more overwhelmingly warm conditions over the US, especially for the eastern US, now this is what a “blowtorch” really looks like.

Here are the temperature anomalies for 2006-07 through mid-January and you can see that the first half of winter in that year was actually even warmer than what was experienced in the 1st half of last winter.

Even in the winter of 2006-07, conditions dramatically turned around in one of the greatest late winter comebacks ever, and this can be partially attributed to the warmer than normal waters that were present at that time over the deep tropical Atlantic, helping to enforce a an upward phase of the MJO, thus a cooler and stormier pattern, despite the overwhelming warmth the first half of winter.

Here is what the temperatures looked like over the US in February 2007 as a result of the tropical Atlantic being warmer than normal. Clearly, the eastern and central US were much colder than normal, which is consistent with the upward MJO towards the Atlantic.

Look at the Atlantic Ocean water temperatures during the winter of 2006-07 as we headed into February, notice how the tropical Atlantic relative to other tropical regions was comparatively warmer.

Here are the February 2007 temperature anomalies and you can see the tropical Atlantic is quite warm, and this should favor upward MJO motion over the Atlantic, which would mean colder & snowier conditions for the eastern US.

Also, look at what happened in 2009-10 in February, big time winter comeback with “snowmageddon” on this date back in 2010.

Here is the temperature anomaly map for late January through the end of February during the winter of 2009-10, and you can see after the warm period earlier in the heart of winter the cold came back and stuck around to the end of winter.

Temperature anomaly map for late January through the end of February during the winter of 2009-10, and you can see after the warm period earlier in the heart of winter the cold came back and stuck around to the end of winter.

After the warm-up in the heart of the winter of 2009-10, within a few weeks what followed was one of the greatest winter storms ever to strike some areas of the mid-atlantic, with major snows through much of the northeast as well.

NASA’s aqua satellite capturing this historic storm that hit February 6th-7th 2010 dumping astounding amounts of snow over the mid-atlantic and northeast.

Snowfall accumulation map from NOAA for Feb 6-7 2010 during “snowmaggedon”, and you can see areas hardest hit include Washington DC, Baltimore, Philadelphia, Fredrick, and into the mountains of northern Virginia and West Virginia, generally along and just south of I-70 was where the worst of the snow fell.

Look, at what happened a few days later on February 9-10, another major winter storm into some of the exact same areas of the mid-atlantic and northeast only hit a few days earlier with crippling snowfall, although the precise axis of snowfall very slightly to the north towards areas of southern PA and in towards Philadelphia.

Here is the snowfall accumulation map from NESIS showing yet another crippling snowstorm that followed after Feb 6-7 storm, creating extreme travel problems and leading to many areas having to dig out of several feet of snow.

As if that was not enough, yet another very powerful winter storm struck the northeast before February was over, this time for areas farther north, with lake effect snow very prevalent off of Lake Ontario and Erie, with a 30 inch + bulls eye near the Catskills of NY and very close to Albany.

The NESIS snowfall accumulation map for February 23-28 shows that yet another crippling snowstorm struck the northeast in February 2010, this time for areas further north.

The winter of 2009-10 as a whole ended up colder than normal, especially for areas further south with a very active subtropical jet stream in place, typical in el ninos, and the month of February certainly contributed very significantly to the colder and stormier than normal conditions for much of the US, especially for the eastern US.

The winter of 2009-10 overall ended up being much colder than normal for much of the US, especially for the southern US as there was a very active and enhanced subtropical jet in place, classic in el nino winters, helping to keep conditions cold & stormy for much of the winter.

Now, many people will remember this winter to be very cold and snowy, although I showed that like this year there was a period of mild conditions in the heart of winter, but what does February 2010 have in common with February 2007? Just look at the tropical Atlantic water temperatures, and you can see yet again, it is the warm waters present over the deep tropical Atlantic that are big reason as to why February was so cold and snowy because the warmer than normal waters over the deep tropical Atlantic force the surrounding air above to warm, thus inducing the air to rise. With rising motion being favored, this influences the upward phase of the MJO into the Atlantic, which is known to make the pattern cold and stormy over much of the US, especially towards octant 2 and 3.

Here are the ocean temperature anomaly map for February 2010 and you can see once again, the tropical Atlantic is warm, so if that’s the case then the pattern should be colder and snowier than normal over the eastern US.

Now, look at this year and compare to February 2007 and 2010, and you can see why I have been pushing since December for the worst of winter to be from late Jan-Feb, look at how warm the waters are over the deep tropical Atlantic. Knowing what happened in February of 2007 and 2010, one can certainly come to the conclusion that this month may not be too much different.

Here are the latest global water temperature anomalies, and you can clearly see like in February 2007 and 2010, the waters over the deep tropical Atlantic are warmer than normal, not only that, but they are also by far the warmest from normal compared to any other area of the global tropics, which is a good reason why the upward phase of the MJO should really deepen into the Atlantic.

A good reason why warmer than normal waters over the tropical Atlantic have led to colder than normal Februarys in both 2007 and 2010 has been the MJO, and you can see when it is in the favorable Octants from generally 8-3, conditions are colder & stormier than normal over the US, especially the eastern US.

Here is the MJO temp composite for December through February, and notice how now that we have been in octants 8 and 1 of the MJO, not only has the pattern turned colder, but much stormier as well as the upward MJO activates the subtropical jet stream.

You might be wondering at this point, why do I talk about Octant 3 of the MJO being favorable, when it is warmer than normal from December through February, but look at what happens as we progress deep into the winter and start to approach spring how the MJO in Octant 3 becomes much colder than normal, with the temperature composite below from February through April showing this change in the effects of the MJO. You can also see just how dramatic this change is from December through February, the most favorable octants are 8 and 1, but this changes to 2 & 3 as get towards February and beyond, which is very interesting to say the least.

Here is the MJO temperature composite for Feb through April and you can see how octant 3 especially changes from being generally warmer than normal to cooler than normal.

Now, another factor that will be helping out this situation for cold is the AO and NAO, both of which are going negative, which is fairly significant because both oscillations have maximum effect when they’re both working in tandem, and there’s a couple of reasons as to why they are going negative.

The NAO forecasts, not surprisingly, have began to forecast a -NAO in the longer ranges.

The AO, also forecasted to go negative by the models as they begin to respond to the conditions at hand.

Of course one of the main culprits as to why the AO and NAO are going negative is because of the SOI (Southern Oscillation Index, a measure of the pressure differential between Tahiti, French Polynesia and Darwin, Australia), with values since the start of February as follows: Feb 1: -26.08, Feb 2: -47.31, Feb 3:-43.04, Feb 4:-32.95, Feb 5: – 31.85, Feb 6: -28.53. More SOI data is available here at the website, which updates once a day on the SOI http://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/30daysoivalues/

Of course, the reason the SOI went negative has a lot to do with the MJO, and you could see this -SOI burst coming several weeks ago. It makes sense given that as the MJO sat over the western Pacific, not only did it produce ample amounts of thunderstorm, where these thunderstorms (as I’ve described in previous posts) create natural turbulence, which goes against the natural east to west flow of weather and winds over the tropics which is created naturally be the Coriolis Effect. Also what the upward MJO did was as these thunderstorms sat over the same region over an extended period of time (evidenced by the MJO stalling slightly in Octant 7) they cool down the surrounding air and water, and their turbulence also stirs up the surface waters, which cools them. As the waters and the surrounding air cools due to the increased and prolonged period of thunderstorm activity, the cooler air and water does not have the ability to lift as strongly as the previously warmer water. Thus over time, the waters cool, and since cooler air is naturally denser than warmer air due to the air molecules within colder air not moving as freely about in cool air, allowing them to stay more compact, which allows for air molecules to be packed in the same amount of space, which gives the air more “weight” thus pressures rise. As pressures rise in these areas over the western Pacific due to the moderated air and water from the increased thunderstorm activity and the MJO moving eastward, air pressures continue to rise, which begins to force regions of high pressure to form over this region. Since in areas of high pressure, air spreads out and goes outward in all directions, and since we are talking about the western Pacific, the only direction at which air can flow is eastward, thus the natural east to west air flow over the tropical Pacific becomes disturbed where air now flows from west to east. This air flowing against the natural east-west air flow and movement of weather over the tropics also disturbs the natural incline of water from east to west over the Pacific, which forces water in the eastern Pacific to rise in response to the sudden slowing of the natural east-west windflow. This creates a displacement of water, which can only be compensated for by large scale waves because of the vast size of the Pacific, and it is these waves which are called Kelvin Waves. Also, with lower pressures moving away from the western Pacific and moving towards the eastern Pacific, this causes the pressures towards Darwin, Australia in the western Pacific to rise, however, the pressures towards French Polynesia in the south-central Pacific begin to fall, thus with pressures higher towards Darwin, Australia as opposed to Tahiti in French Polynesia, the SOI goes negative, which is exactly what we have witnessed since the start of February as the MJO moved eastward across the Pacific.

Here is and MJO forecast from January 21st, where you can see my point as to why it makes sense that this sudden SOI burst occurred.

The ECMWF MJO forecast from over a week ago showing this MJO heading towards the extremely favorable octants 2 and 3 in the long range, which makes sense given how warm the waters are in the deep tropical Atlantic to promote upward motion to support an upward MJO phase, and this supports the potential for a “Fun February” like what was observed in 2007 and 2010.

An old ECMWF MJO forecast showing the MJO going towards octants 2 and 3 later in February.

Now of course, when you have a -SOI, this helps to activate the subtropical jet stream, and when you activate the southern branch of the jet stream, this gives a better opportunity for phasing of other branches in the jet stream and allows for systems in the northern branch to dig deeper and strengthen fairly significantly, which is what we are beginning to see now, especially with this first major winter storm in the northeast. What the -SOI along with the upward MJO pulse does over the Atlantic is as the upward MJO pulse moves over the tropical Atlantic, it forces rising motion, causing thunderstorms to form over the tropics and atmospheric pressures to lower over the tropical Atlantic. As pressures lower in the tropics, this allows for the subtropical jet to strengthen and more troughiness to take over in the Atlantic. This also means that with the Azores High that is normally present northwest of Africa, this troughiness and low pressure influenced by the upward MJO forces the region of high pressure to weaken or even be replaced by an area of lower than normal pressure. This area of lower pressure here in the Azores also effects the area of low pressure normally present near Iceland & Greenland, and with lower pressures towards the Azores, this forces atmospheric pressures to rise towards Greenland, and when you have higher than normal pressures near Greenland “blocking” this means the NAO goes towards its negative state, which is exactly what we are seeing now as the models begin to respond to this.

This picture helps you to better understand how lower pressures are influencing the Azores High to weaken, thus allowing for blocking to begin to develop towards Greenland.

Here is a composite of some of the deeper negative NAOs since 1950 and in this picture represented by the shades of blue and purple are lower pressures (as you can see towards the Atlantic, and in our case being induced by the upward MJO). With below normal pressures in the Azores, this forces pressures to rise towards Greenland, indicated by the deeper shades of yellow and red, thus -NAO, which favors big east coast storms is formed.

The GFS ensembles for several days now have been locked onto this idea of a -NAO developing as February progresses, thanks to the upward MJO, (especially as it heads towards octants 2 and 3 for maximum effect), and this along with the -SOI promoting low pressures towards the east Pacific, indicated by the troughiness (in blue) extending all the way back to Hawaii helps to promote deep mid-latitude troughs over the eastern and central US to go along with the active subtropical jet in place.

The GFS ensembles for several days now have been indicating a classic winter weather pattern for the central and eastern US. You can see in this picture how the MJO influencing upward motion and troughiness towards the Atlantic forces pressures to rise directly towards the north near Greenland, which causes upstream changes in the pattern forcing troughiness in the eastern US, which is then further aided and deepened by the active subtropical jet stream in place with troughiness extending all the way back to Hawaii.

To make matters even better, we have the stratospheric warming event still ongoing below 50 millibars in the stratosphere, and although the temperatures in these levels of the atmosphere are cooling, they still remain high, with 70 millibar temperatures still near record levels. This continued warming at this level means air is expanding due to the warmer than normal temperatures, in doing so, this forces the lower layers of the atmosphere, like the troposphere to contract, thus being indicative of ongoing cooling and this forces pressures to rise in response, thus the AO has a tendency to go negative as well along with the NAO going negative due to the MJO forcing troughiness and pressures to lower near the Azores.

Here are the current 500 millibar temperatures, starting to cool finally, but still still quite warm, you can also see the red line, being this year how it surpassed the top black line, meaning we broke a record for all-time warmest since the beginning of the satellite era in 1970, for a period of time in this level of the stratosphere.

Here are the current 50 millibar temperatures (shown by the end of the red line), and you can see the top black line, which is record territory, just how warm the stratosphere got in this warming event, and you can see we are still above normal (the dotted green line), but are quickly plunging towards colder conditions.

The 70 millibar temperatures show that it is still much warmer and near record warm conditions in the lower levels of the stratosphere as this warming event propagates its way to the surface. You can also see like in the 50 millibar chart above, the stratosphere in this level also broke a record for being warmest for a period of time during this warming event.

The 70 millibar temperatures in the lower level of the stratosphere for this year helping to reveal the significance of this most recent stratospheric warming event.

Also, let’s not forget about the 30 day sunspot cycle and its relation to the pattern and the PNA, and it is amazing to see, like what was observed in late December, how when we have a lull in sunspot activity that suddenly the pattern over the eastern US responds with periods of cold & snow, and it seems like we are seeing another one of those yet again as the sun oddly goes dormant near the peak of solar cycle 24. Also, the “Postdam Ap” when it is lower than normal, which is what we are seeing at this point in time, it pushes for more high latitude and arctic blocking, which along with the MJO and the stratospheric warming event, makes a whole lot of sense as to why the AO & NAO are going negative.

The 30 day sunspot cycle also having influence on the pattern, with its inverse relationship to the PNA, and now with it low again like what was seen in late December, it really is no wonder why this pattern is becoming so favorable for cold and snow.

Taking all of this information into account, including the stratospheric warming event still ongoing in the lower stratosphere, the MJO and SOI support allowing for a stronger southern branch of the jet stream and helping to force the NAO & AO negative as a trough over the Atlantic where the upward MJO pulse is, subsequently forces pressure rises towards Greenland, thus it shouldn’t be a surprise to anyone as to why the NAO is going negative, despite what some of the models were saying only several days ago. With all of this information at hand considered along with the parallels with the warmer than normal water over the deep tropical Atlantic like what was observed in 2007 & 2010, not to mention the northern hemisphere snowfall anomaly for October which suggested a pattern like this would occur, it is no wonder this pattern has turned colder with the worst of winter currently upon us. The CFSv2 sub monthly ensembles seem to really like this pattern, and shows that even the southern US may get involved before this is all set and done.

Here are the CFSv2 sub monthly snowfall forecasts through mid-late February showing that the worst of winter is upon us and that there is a considerable amount of cold and snow left to go before spring arrives.

Now that we know the conditions at hand let’s apply this to the models and see how these factors among many others are specifically influencing the pattern at hand. I am going to use the ECMWF for this model and pattern analysis as it has been by far the best performing model historically but also was the first model to catch this major snowstorm near the east coast, but will also show other models.

The current set-up reveals the last of the series of clippers departing off of the east coast of the US as it rotates around the very persistent gyre of low pressure visible just east of the Hudson Bay. Behind this clipper some cooler air is filtering in (also plays a part in this next storm’s development), with the real area of interest everyone in the northeast and New England has their attention on currently over the northern Rockies with the trough axis currently centered near Nevada, this will be the system in the northern branch of the jet that helps to lead to this large snowstorm near the east coast. Another notable feature is the region of troughiness visible over SW Texas in association with the active subtropical jet stream being influenced by the sudden -SOI burst and the upward MJO, both of which are helping to keep this disturbance energized. Also the next trough of low pressure about to come onshore over the Pacific northwest will play a large role in the system that comes out and produces snowfall over the northern plains and the Valentine’s Day system that could effect areas farther to the south and east of this current storm that will hit areas of New England and the northeast.

Here is the initialization of the ECMWF model and you can see the players at hand with the gyre of low pressure over eastern Canada a ridge towards southern Canada with the next trough sitting over the northern Rockies and another one to follow about to come onto the Pacific northwest coast. You can also see with the active southern branch of the jet in place a system near the southern plains as a result, which will be a big key as to why this trough of low pressures becomes very strong as it bombs out near the east coast.

By 24 hours the clipper system that was off of the east coast of the US has moved towards Atlantic Canada and is moving away along with the gyre of low pressure just east of the Hudson Bay which is beginning to retreat northward. The main feature everyone will be watching is the trough that is currently over Nevada and the northern Rockies ejecting eastward out into the northern Plains here with the trough of low pressure near the west coast, which is digging southward into response to a building ridge over the Gulf of Alaska that is strengthening due in part to the subtropical jet stream underneath over the eastern Pacific forcing pressure rises to the north in this area, and of course the 30 day sunspot cycle which also favors a +PNA signature, which calls for a stronger ridge near northwestern North America. Also noticeable is the feature that was over Texas now moving eastward across the southern US, with this disturbance being noted on the ECMWF to be near Mississippi and Alabama, and this disturbance is producing heavy rains and some thunderstorms over this area, which is allowing to attain plenty of Gulf of Mexico moisture on its trek east-northeastward. Also what should be noted is the next trough barely visible in the top left corner of the screen near the Bearing Sea, and also with that trough over the northern plains that will help to produce the snow in the northeast, there is a shortwave disturbance just to its northwest over extreme northern Alberta and Saskatchewan (and Alberta Clipper) which is helping to add some energy into the trough from the northern branch of the jet stream.

Here is the 24 hour of the ECMWF showing the players in the pattern described in the description above coming into play.

At 48 hours, the main feature being the trough that was over the northern plains continues to move eastward along the mid-latitude westerlies towards the Great Lakes, and along with it is still somewhat of a shortwave disturbance that was over northern Alberta and Saskatchewan at hour 24 helping to add a little energy into this system, which is one good reason why the trough looks more pronounced at this time. However, a piece of that shortwave disturbance split off and is now centered over Nunavut and has got caught up into the gyre of low pressure now centered just north of the Labrador and Quebec Canadian provinces. Also, the shortwave disturbance that was over Texas at the initialization has shifted eastward and is now located off of the North Carolina coast and is beginning to form a nice surface low off of the coast. Also, another disturbance has entered the subtropical jet and is now visible over the southern plains and near the Arklatex region as the main feature being the trough of low pressure over the Great Lakes is moving at a faster speed than at its trough base, thus energy is getting left behind, giving the trough somewhat of a positive tilt, but this is dramatically changing as the trough over the Great Lakes begins to interact with the disturbance forming off of the Carolina coast. Also, the trough of low pressure that was off of the Pacific northwest coast at the beginning of the model run continues to dig southward along the west coast of the US in response to the strengthening ridge over the Gulf of Alaska which is indicative of a +PNA, and this ridge is likely being influenced by the lower 30 day sunspot cycle and the upward MJO pulse underneath forcing substantial pressure rises and causing dramatic changes in the pattern downstream.

Here is the ECMWF at 48 hours showing the pattern coming together for this major winter storm over the northeast.

At 72 hours, the moment of truth has arrived as the system rapidly intensifies near the east coast. The trough that was over the Great Lakes has merged with the disturbance that was over the southern US, helping to create a much stronger storm that is going through rapid intensification due to the unusually favorable environment at hand. When you look at what is occurring here, you can see how the conditions at hand like the MJO and the 30 day sunspot cycle are having specific effects on the pattern at hand. As the MJO and sudden -SOI burst forces troughiness over the east Pacific and pressure rises over the west Pacific, atmospheric heights are pumped directly to the north of it over the Gulf of Alaska, and to add to this, the 30 day sunspot cycle having an inverse relationship to the PNA means with the sunspot cycles remaining low and getting even lower, this forces the PNA to go towards its positive state. The PNA in its positive state means a region of high pressure is favored near northwestern North America and even in and around the Gulf of Alaska. A building ridge of high pressure here forces the next trough directly in front of it towards the west coast to dig deeper in response, thus pumping the heights out in front of it, and it is these stronger heights building in behind the trough of low pressure near the east coast which help to force air to rush into the system. Air rushing into the system at the surface is very crucial for this storm’s intensification, because in this instance we do not have at this particular time, a -NAO with higher than normal pressures near Greenland to feed these systems near the east coast, thus there must be another mechanism at which they can have air rush into them, and this occurs as the atmospheric heights rise behind the trough of low pressure. Also, another factor that has influence on this storm is the fact that cold air is being left behind in the wake of this most recent clipper system which has exited the east coast. This cold air is a big part to helping to force rapid cyclogenesis of mid-latitude cyclones, especially over water where the ocean has 1000x the energy capacity of air, thus more available fuel for any region of low pressure to rapidly intensify, and as the cold air gets left in the wake of the clipper system, the cold air forces the air near the surface to sink, however, in relation to the significantly warmer water below, large amounts of instability are created, yet no significant thunderstorms can form because of the high pressures being left in the wake of the trough helping to put a “cap” on any activity, however, as the next trough comes along, this begins to force pressures to lower, thus the “cap” breaks, sometimes violently and thunderstorms form, and as their processes continue over a period of time, this forces the surrounding air pressure to lower as latent heat is released. As more latent heat is released, the area of low pressure draws in more air at the surface, at least in our case with the ridge of high pressure sitting to the west of this system, this helps to feed the low pressure and allow for further intensification. Also helping to intensify this storm is the orientation of the storm system in the southern branch in accordance to the system in the northern branch that will be moving through the Great Lakes, and because the southern system is out ahead of the disturbance in the northern branch, this forces that disturbance to play catch up and lean towards the southern system, thus giving it a negative tilt, (orientated from SE to NW from trough base to the top of the trough), which is characteristic of strong troughs of low pressure.

Here is a picture giving you a better idea of how this process works where in this picture we start with the exiting trough leaving behind cooler air, creating instability, and higher pressures aloft helping to severely limit thunderstorm activity.

Now as the next trough comes through, the lower pressures aloft help to break this cap, thus thunderstorm activity increases dramatically and helps to intensify any region of low pressure near or just off of the coast.

Now, a similar storm that has been mentioned by professional meteorologists like Joe Bastardi at weatherbell who definitely deserves credit in pointing out this similarity (suggest getting a subscription to the premium site) is the “Lindsay Storm” of 1969, which came into and struck the northeast on almost the exact same date as this next storm is coming into the northeast with a very similar set-up and pattern going into the formation of the storm. This storm in 1969 which effected the exact same areas of the northeast under the gun with this next upcoming storm formed in a very similar manner as low pressure off of the Carolina coast met up with a disturbance in the northern branch which helped to form a storm off of the east coast. Now, this storm (as Joe Bastardi has said) did not have a considerable amount of blocking at the time to feed air at the surface into the storm, thus another mechanism triggered air to suddenly rush into the storm, and when you look at this picture below, you can clearly see the higher pressures indicated in shades of green, yellow, and orange buliding in the wake of the storm in response to the strong trough of low pressure near the west coast of the US. This ridge of high pressure allowed for air to rush into the intensifying storm off of the east coast, and although the trough off of the west coast of the US is a little farther to the west than the trough in our situation, it performs the same job as our current trough. Also notable is an active subtropical jet stream at this time indicative of the lower than normal pressures (in blue and purple) underneath the ridge over the US and just off of the Baja Peninsula and into Mexico, which tells me that the active southern branch of the jet stream helped to play a big part in this storm as well, not just the ridge in the central US being pumped by the trough off of the west coast.

Here is a pressure map from the Lindsay Storm of 1969, and here you can see the overall pattern is somewhat similar to what we are currently seeing.

Here’s another look at this storm using sea level pressure.

Here is the sea level pressure pattern for the storm that struck the northeastern US on Feb 8-10 1969, and you can see it looks somewhat familiar to the current set-up, although there are some differences in the placement of the trough off of the west coast of the US.

Here is a snowfall accumulation map of the “Lindsay Storm” which caught many off guard in the NYC area who were only expecting little to no snow at all, to turn around and be having to measure the snow in yardsticks.

Here is the NESIS snowfall accumulation map of the “Lindsay Storm” in 1969 which shares some similarities to this current system as Joe Bastardi has been saying for several days.

The ECMWF’s depiction of this storm, as explained above seems to make the most sense to me as it appears to be correctly handling the pattern at hand, and not only that, but it was also the first model to pick up on this storm so definitely deserves a lot of attention in this case.

Here is the ECMWF at 72 hours showing our system near the east coast, and the next system that will have impact on the east coast waiting towards the western US.

According to the latest ECMWF snowfall this is what it looks like in the northeast with it breaking down like this for some of the big cities on the I-95 corridor, not my forecast, just what this particular model is saying

Boston: 18-25 inches

Hartford: 18-24 inches

Providence: 18-24 inches

New York City: 10-14 inches

Philadelphia: 3-5 inches

Baltimore: 1-2 inches

Washington DC: flurries, perhaps a light coating in some areas

Here is the ECMWF showing a major snowfall of 1-2 feet possible over southern New England with some locally higher amounts.

Here is the GFS’s depiction of the storm, as you can see it is a little bit flatter with the trough than the ECMWF (which can be anticipated), plus the model has had to correct towards the ECMWF solution, thus may get more aggressive with the snowfall totals later in time

The GFS model at 72 hours showing this storm over the northeast, although not as strong as the ECMWF and this can be attributed partially due to the model’s natural progressive bias

The GFS’s thinking on snowfall totals in the big cities of the northeast

Boston: 10-15 inches

Hartford: 7-10 inches

Providence: 8-12 inches

New York City: 5-8 inches

Philadelphia: 2-4 inches

Baltimore: flurries, light coating up to 1 inch

Washington DC: flurries, perhaps a dusting or half an inch in spots

Here is the GFS snowfall accumulation with this storm

The CMC model’s depiction of snowfall, although I do not agree at all with this model, and think it has some serious adjusting to do, but even still, a good snowfall for southern New England

The CMC model’s depiction of this storm

Here is the snowfall from the CMC, and I do not agree at all with this model, think it will be forced to adjust as we get closer to this storm

Boston: 7-12 inches

Hartford: 4-7 inches

Providence: 5-8 inches

New York City: 1-3 inches

Philadelphia: none

Baltimore: none

Washington DC; none

CMC model’s 72 hour snowfall

The NAM’s depiction of this storm

Here is the NAM’s snowfall, although I do think it is too far north and will be required to adjust southward towards the ECMWF and GFS as time progresses.

Boston: 15-20 inches

Hartford: 1-3 inches

Providence: 3-6 inches

New York City: flurries, accumulations under 1 inch

Philadelphia: none

Baltimore: none

Washington DC: none

Taking all of this information into account, and considering the conditions at hand and the solutions being provided by the models, here’s where I currently stand as far as snowfall goes for the big cities Boston 16-20 inches (2 feet or more in some areas) Hartford and Providence: 14-18 inches (some areas may approach 2 feet) New York City, very tough call at this point and likely to change, but going to go with 4-8 inches for now, Philadelphia at least some flurries, think a light accumulation of 1-3 inches certainly a possbility. Washington DC and Baltimore may end up with nothing but some flurries and a light accumulation of 1 inch of snow can not be ruled out, especially for areas farther to the north and east.

As we get beyond this storm by around 120 hours it has exited well out of the picture and is effecting Atlantic Canada as it gets absorbed into the polar jet and gets tangled in the gyre of low pressure that has now retrograded to just west of Greenland. Also of note is the trough that is currently off of the northwest coast of the US now entering into the plains as energy from this trough splits into two pieces. The reason for this is an alberta clipper shortwave will develop over the Rockies in Alberta and British Columbia, in doing so, it will influence the trough of low pressure in the western US to get tugged to the north, however, since the base of the trough extends very far to the south into the southwestern US, only a certain part of the trough can “feel” this shortwave disturbance, thus the trough splits with one piece moving northeastward and giving a large amount of snow to the northern plains and upper Great Lakes area early next week. The real feature that will begin to receive attention is towards the base of this trough over the southwestern US, because as it kicks eastward, we could see, yet again, another merging of two disturbances, thus there will be concern for yet another storm system in the eastern US, although this time farther to the south and east than the next system coming this Friday because the feedback from the snowpack will influence the surrounding air to cool, thus forcing the surrounding pressures to rise, and with higher pressures in place to the north of the developing low pressure system, these low pressures will tend to deflect the storm system farther south and east towards areas of the mid-atlantic and northeast rather than into New England. Also notice the ridge of high pressure near the Gulf of Alaska hanging tough as it continues to pump low pressure heights into the trough over the central US.

The ECMWF for 120 hours showing our major winter system departing with the next storm coming into the picture in the midwest with the next area of concern associated with that trough over the southwestern US.

By the time we get to about a week from now, we can see this trough that went into the upper midwest exiting north America towards Atlantic Canada, not before producing potentially a little bit of light snowfall accumulation in the northeast, especially along and north of I-90. By this time though, attention will begin to shift to what is brewing over the southern US as the trough of low pressure that was over the midwest splits in two, the first piece already producing snowfall over the upper midwest, Great Lakes and into southern Canada, while the disturbance near the base of the trough over the southwestern US lays back some, however it soon kicks out and becomes energized from the increase in Gulf of Mexico moisture, the strong north-south distribution of temperatures and pressure over the central and eastern US that has been created in part by the snowfall, not to mention the upward phase of the MJO providing energy into the subtropical jet stream for this system to feed on, but now, all that is necessary for a big storm is some kind of phasing with a system in the northern branch. Also notice there is also more energy laying back behind this trough over the southwestern US, and although this can partially attributed to the ECMWF’s bias to withold energy in the southwestern US too long, it is a reasonable solution given the active subtropical jet stream. The ridge of high pressure near the Gulf of Alaska also still trying to stay intact, and it should do so as the MJO underneath forces pressure rises into this area and the low sunspot cycles continue to enforce a +PNA regime with higher than normal pressures near northwestern North America.

ECMWF model for 168 hours showing the pattern continuing to progress as the attention will begin to shift to the system that is gathering over the southern US

Just for fun, look at the ECMWF here as we get out towards the end of the run, and although nothing should be taken literally, you can see it does seem to hint at the potential for yet another system to come towards Valentine’s Day with a fully-developed trough just to the east of New England, and also as you look downstream there’s another system over the southern Rockies, which makes sense given the MJO and -SOI enhancing the subtropical jet stream and allowing for intensification of systems and merging with troughs in the northern branch. Also notice the ridge near the Gulf of Alaska is hanging tough, likely suggesting a +PNA regime will be in place for the foreseeable future, which will aid the east coast in getting big winter storms along with the AO and NAO which are going negative in response to the ongoing lower stratospheric warming event and the upward MJO pulse.

The 240 hour ECMWF showing my concern for yet another east coast storm around Valentine’s Day with a large area of troughiness sitting near Atlantic Canada.

In general, if you are in the northeast, especially in southern New England, you should be anticipating a crippling snowstorm with strong winds heavy snow, and even the potential for thunder and lightning because of how dynamic the low pressure system is and the rate of intensification it will be undergoing as it bombs off of the east coast. From here, there will be another trough of low pressure to follow which will split in two, with the first piece of energy resulting in snowfall for the upper midwest and Great Lakes, while the second piece of energy stays behind and comes out to pose a significant threat for a major winter storm near the east coast around mid month, likely farther to the south and east from the current storm. Also, using the conditions at hand like the MJO, 30 day sunspot cycles and knowing their influence on factors like the NAO, AO, and PNA, one soon discovers this pattern is going to turn quite cold, and with historical relation with the warm waters over the deep tropical Atlantic to some cold and snowy Februarys like 2007 and 2010 there is even more evidence to support this. Of course this kind of pattern does have implications on spring and the tornado season, which I will discuss some of my thoughts on in upcoming posts, plus take another look into the hurricane season and hopefully give you a general idea of what to expect based off of what I am seeing at hand, history, and other forecasts, plus I hope to take an even deeper look into the AO/NAO and look at yet another factor that has strong relationship to how these oscillations behave from year to year and over longer periods of time.

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About the author

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.

31 comments

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Mike DiLeo

February 7, 2013 at 12:48 am (UTC -4) Link to this comment

@ Eric
Excellent post man i’ve been learning so much from you. So many people that were complaining about winter being over are dead silent right now because they have nothing to say. You were right. well It’s a tough call here in central Jersey, im praying the storm could pull in a little more cold air and give us good snows. In the winter of 2010-2011 we had a storm similar to this one that briefly started a snow, changed to rain, then back to snow overnight with 6 – 9 inches expected , and we ended up with 19 inches as snowfall rates neared 4 inches per hour for a good 3-4 hour window. Anythings possible. I won’t give up hope just yet, we’ll see what happens.
AutoFill Rob

February 7, 2013 at 4:03 am (UTC -4) Link to this comment

I think this is gonna be big in NYC,already the nws has upped their totals here from 3-6 to 8-12.
Let’s see if the trend continues up!
Eric

February 7, 2013 at 6:57 am (UTC -4) Link to this comment

@ Mike Dileo
I’m glad you learned a lot in this post, and you are exactly right about central NJ because it will be a very tough call on snowfall, but it looks like you should definitely see some snowfall on the backside of the system as colder air is drawn in aloft and at the surface, and of course with this kind of cold air trying to be drawn in and with a rapidly intensifying mid latitude cyclone, you have to consider the potential for thundersnow with this as well. Plus, even if this storm does not really give you a nice snowfall, you have plenty more where that came from as another major system from the trough of low pressure off of the northwest coast of the US could make things interesting around Valentine’s Day.
Eric

February 7, 2013 at 6:59 am (UTC -4) Link to this comment

@ AutoFill Rob
Now, you were trying to tell me winter was over because you didn’t see any snow, yet didn’t I tell you not to turn your back on winter, and all it takes is one snowstorm and suddenly the winter isn’t a bust anymore, well you’re about to get that one snowstorm, plus there may be more where that came from as we approach Valentine’s Day.
John Michael

February 7, 2013 at 7:53 am (UTC -4) Link to this comment

Eric, you heard about what the models started picking up on yesterday, right? About the cut off low forming off Cape Cod? They’re saying if that low develops like they expect this thing could get cut off from the jet stream and stall, throwing heavy, heavy snow bands back in from the northeast.. Basically if that happens then some people could get stuck under these heavy snow bands approaching and possibly exceeding 3-4 inches an hour! That’s where my area could get up to and possibly over 3 feet! Well, this is what happens when you go almost 2 years without a good storm.. Mother nature has to play catchup! We have been quite literally in a snow drought for the past 24 months and I think the chickens are about to come home to roost!
Chris

February 7, 2013 at 10:17 am (UTC -4) Link to this comment

Eric,
What are your thoughts on the possible valentines day snow storm for south eastern Pennsylvania? I live in Manheim,PA northern Lancaster county. I would love to see a nice size/ HUGE snow storm for our area what are your thoughts? I know it’s a little far out but always nice to be up on thing like this plus i travel a lot so i try to work around the weather at times when i can.
hockeymom

February 7, 2013 at 12:12 pm (UTC -4) Link to this comment

nothing for Atlanta I think it’s time to move up north
Dustin

February 7, 2013 at 12:23 pm (UTC -4) Link to this comment

Eric These modles show GFS,rain and Euro going out to sea for the 14th Storm for central VA what our your thoughts since,the model keeps showing this.
KPR

February 7, 2013 at 1:14 pm (UTC -4) Link to this comment

I have been trying to post a comment but they never show up. This is a test.
John Michael

February 7, 2013 at 2:57 pm (UTC -4) Link to this comment

I just want to add from my post earlier that all the while this system will be stalling off the coast of Massachusetts Friday night, you’ve got a big old fat juicy high pressure system sitting up over Quebec, Canada basically acting like a bridge troll saying “you shall not pass” compounding the problem! This is going to be a MONSTER! Eric, I don’t know about you, but I think this could be the ONE.. We’re going to be breaking some records here.. I think we might even take a run at 78′. All we need is for some of those thunder snow bands to set up over Logan airport (where Boston takes its snow totals from) and there’s a damn good chance we shatter records here folks! People, if you live anywhere from northern New Jersey, to Maine.. PLEASE BE SAFE. This is a SERIOUS SITUATION devoloping here.. You don’t want to be out on the roads past 3-4 o’clock tomorrow! Life or death situations could arise. Heed the warnings. Stay home. This could easily be one of the biggest if not the BIGGEST storm New England has EVER seen. As for me, I couldn’t be any happier. Last I heard, Jim Cantore from The Weather Channel is on a plane to Boston as we speak.. You know when he shows up, it’s bad.
AutoFill Rob

February 7, 2013 at 4:09 pm (UTC -4) Link to this comment

Well Eric my apologies for sometimes doubting this winter was gonna be anything special… NYC just upgraded to blizzard warnings! Whoa
Eric

February 7, 2013 at 4:13 pm (UTC -4) Link to this comment

@ Autofill Rob
I forgive you, and I am actually thinking snow totals for NYC are going to be quite large, historic even with my ideas now for 10-14 inches in the NYC metro area. Even Philadelphia will have to keep an eye on this storm, they could see snow totals close in on 6 inches, and even areas towards Washington DC and Baltimore look to see at least some snow from this, although light accumulations will be the case regardless.
Eric

February 7, 2013 at 4:17 pm (UTC -4) Link to this comment

@ John Michael
I wouldn’t really call this year to be included in the snow drought up to now, although snow has been below normal not extremely overwhelming, and this storm I do think will be very historic for the Boston area for sure, and yes you can not rule out the possibility for isolated areas to see snowfall totals up to 3 feet in the stronger thundersnow bands that will develop.
Eric

February 7, 2013 at 4:20 pm (UTC -4) Link to this comment

@ Hockeymom
Don’t hold your breath, this pattern will become even more favorable as time progresses and I think it is not wise to call this winter over or to give up, because look what is happening to the people in the northeast who thought it was over (including Yamahas), they’re going to see an absolutely historic and crippling snowstorm not seen for decades in areas of New England with snowfall rates that may reach or exceed 3-4 inches an hour in some areas.
Armando

February 7, 2013 at 4:23 pm (UTC -4) Link to this comment

Wow Eric can’t believe whats happening like its been 2 year since a MAJOR storm occured! Like I remember a couple days ago they were saying rain and a high of 40, but sike! You were right all along since last week wow! Fantastic job Eric! So i’m under a blizzard warning as well and o boy sat, im going to make a lot of money lol! So would you say 10-14 for me as well? Joe B is calling from 12 to 24 for us and i wouldn’t be shocked if i saw more than 14 inches lol! Cant believe this is happening! How could anyone not love the weather haha!
Eric

February 7, 2013 at 4:54 pm (UTC -4) Link to this comment

@ Dustin and Chris
Well, you can’t get lost in the models on this storm, let’s just remember where were the models on this storm tomorrow for New England several days ago? Not much snow at all with a system departing out to sea, and with the conditions at hand changing due to the MJO and the -Southern Oscillation Index which may be causing major feedback issues in the models, which could be a good reason why they had trouble picking up on this storm earlier due to the dynamical pattern. The most trusted model at this time and the one that was the first to pick up on this storm, the ECMWF shows a relative area of troughiness near the east coast around Valentine’s Day, but shows the trough of low pressure taking on a positive tilt, with energy laying behind in the southern branch of the jet stream, thus no big storm is popping up on the model. However, you should know by now if you already don’t that the ECMWF has a bias to be too slow with troughs of low pressure in the southwestern US in which this system will originate from. When the system is too slow like the ECMWF shows, energy lags behind, thus no major phasing can occur, however, knowing the ECMWF is known to do this, if the energy in the subtropical jet stream were to speed up, as it should and meet up, if not be ahead of the energy in the northern branch of the jet, then we could have a major storm on our hands because the southern branch energy would force the northern branch to catch up, thus the trough can take on a negative tilt, which is indicative of very strong low pressure systems. Plus, if a storm were to form, it would not strike the same areas currently being effected by this crippling snowstorm in the northeast, because the accumulated snowfall from that system, like all snow, reflects 85-90% of incoming solar radiation, thus forcing the surrounding air to cool, and as it does so, the cooler air raises surface pressures, thus increasing the influence of “blocking”, and it is this blocking that helps to deflect areas of low pressure away from a particular region, thus there is concern that once the ECMWF model corrects, with the conditions at hand, and knowing tendencies of winter storms, I am inclined to think you will have to keep an eye out for this system on Valentine’s Day, and of course there are indications that even if this storm does not result in a big winter storm, there will be yet more opportunities for snow to follow as the pattern should remain favorable for at least the next several weeks.
Eric

February 7, 2013 at 4:57 pm (UTC -4) Link to this comment

@ Armando
Yes. this really is amazing, although I wouldn’t call for 10-14 inches in your area as there will be a sharp gradient in snowfall totals from northeast to southwest, but I think 6-10 inches is a good call, with the potential for a foot, and yes how could you not love the weather, because as he says it really is the only weather we’ve got.
KPR

February 7, 2013 at 4:57 pm (UTC -4) Link to this comment

Ok let me try this again as this will be my 4th attempt. Eric- Awesome post this morning, thanks. I guess it is apparent that the pattern has changed and I suspect it is just a matter of time before it changes in other parts of the country. There are a lot of great East Coast weather blogs but not a lot of West Coast ones. BA at Open Snow does a nice job and I am wondering what your thoughts are. The MJO is moving and the SOI is tanking so now the ridge off the West Coast needs to move a little further west so storms can move into CA. There has been a snow drought in the Sierras for several weeks now, what are your thoughts for it ending. TIA.
Mike D

February 7, 2013 at 4:58 pm (UTC -4) Link to this comment

Armando, I’m going absolutely crazy! Will be up all night!
KPR

February 7, 2013 at 5:08 pm (UTC -4) Link to this comment

OK, now that I can post……….even though I will see all rain, 2-4″ here in VB, I too will be watching the models, blogs and tweets all night as epic snow events like this don’t happen too often. I know all the interest is in this storm but I am starting to look at next week as the EC has the 0 line flerting with VB on Wed when the next systems comes through. Could be interesting again.
Mike DiLeo

February 7, 2013 at 5:16 pm (UTC -4) Link to this comment

@Eric. Well the models are continuing to indicate more cold air will be involved with the storm and the big snow totals keep slowly shifting further south and west. Im feeling much more confident in my area getting in on good snows than when i commented last night. Im so close to nyc i hope we can get into that 10 to 14 inch zone if this trend persists.
AutoFill Rob

February 7, 2013 at 5:18 pm (UTC -4) Link to this comment

@ Eric…do you feel the dynamics will be there for mesoscale banding?(hope I spelled it right!)..and thundersnow? N if this happens then we definitely could be in the 2′ foot mark??
armando

February 7, 2013 at 6:00 pm (UTC -4) Link to this comment

O really you say 6-10? Well the NWS has for my area 10-14 and blizzard conditions plus the models are going toward a colder solution. Also I’m only 20 miles west of NYC so I believe we will be with them with the accumulations. Also if we get this banding that could produce 2/3″ per hr then we could be really in for it, which I’m confident we will but we’ll see.
Mike D

February 7, 2013 at 11:43 pm (UTC -4) Link to this comment

Hey, told you I’d be up most of the night….12-18!!!!!!! I’m sticking to 10-16, but new 00z NAM guidance shows differently – 24+!!!! Making a quinzee tomorrow (Igloo made of snow). Have fun with the snow. A foot will bring us to normal snowfall for the season!
Mike DiLeo

February 8, 2013 at 12:05 am (UTC -4) Link to this comment

Not saying this is how things will happen, but the new run of the NAM looks amazing!
Eric

February 8, 2013 at 6:41 am (UTC -4) Link to this comment

I do see everyone’s comments and concerns and will answer them later this evening, been busy lately as I usually am on Tuesdays and Thursdays.
Eric

February 8, 2013 at 4:39 pm (UTC -4) Link to this comment

Heres something that will certainly surprise many of you, Washington DC, Baltimore, New York City, Philadelphia, and Boston have NEVER seen a 30 inch or more snowstorm, yet Beaumont, Texas just east of Houston along the northern Gulf Coast actually has, back in Feb 14-15 1895, unbelievable but true. http://www.srh.noaa.gov/lch/?n=snowclimo
Armando

February 8, 2013 at 4:49 pm (UTC -4) Link to this comment

Wow Eric thats very fascinating! So over here we have almost 3 inches and worst is yet to come! So as of now what do you think I could end up when its all said and done? Joe B still has for us 12+, and everyone else has scattered accumulations. Also I see a storm for us next week as well lol and from the looks of things we could be in the “jackpot” area! Wow exciting times ahead!
Eric

February 8, 2013 at 5:47 pm (UTC -4) Link to this comment

@ KPR
Thank you for liking my post, I’m glad you enjoyed it, now of course as far as the Sierra snow drought it makes sense that this is happening given the +PNA, and of course if you look at my post above I mention the relationship with the PNA to the 30 day sunspot cycles, and right now the 30 day sunspot cycles have gone very low, and since the PNA and the 30 day sunspot cycles have an inverse correlation, this recent lull in activity is only helping to boost the +PNA, and I do not see this ridge moving too much over the next few weeks as the MJO in octants 2 & 3 with a +PNA, and -NAO this means a cold stormy pattern for the eastern and central US with warmth over in the western US. Obviously, this will end at some point, and there could be a trough or two that swings through but when you’re in a pattern like this, and not to mention the overall state of the PDO is cold, which means when you have cooler Pacific waters, naturally have trouble carrying Pacific moisture, which makes areas, especially in the central US drier than normal. I am not all that familiar with forecasting weather in the western US and all of the shortcuts, hints, and tricks involved, plus it is somewhat difficult to predict the weather out there because of the lack of data stations over the Pacific and western US compared to the central and eastern US, and this will be a personal future goal of mine to try and get familiar with forecasting the weather in the west, which is something many weather enthusiasts and meteorologists here in the east are not quite as familiar with.
Eric

February 8, 2013 at 5:54 pm (UTC -4) Link to this comment

@ AutoFill Rob
Yes, I think the set-up is very favorable for mesoscale banding and thundersnow as we see tow merging areas of low pressure fusing together making each other stronger, and adding even more instability into the atmosphere, plus the temperature and pressure gradient across the northeast, especially southern New England will be very strong as there will be a great difference in temperature from the warmer Gulf Stream waters off of the coast to the colder temperatures inland, and this will only be enhanced by the natural land configuration as the wind begins to shift out of the northeast, areas along and northwest of roughly I-95 will be getting cold air from Canada, while that same northeast wind for areas farther south and east coming from the waters east of Boston will help to slightly moderate temperatures, thus there will be a strong temperature gradient over a short area, a favorable environment for heavy thundersnow bands to develop, especially towards CT, RI, and MA.
Eric

February 8, 2013 at 6:02 pm (UTC -4) Link to this comment

@ Armando
That’s interesting, but it looks like significantly heavier totals will be just to your east, especially once you get east of I-87 in NY, and I think you’re going to end up with 10-14 inches, of course there will be isolated areas that see sudden downbursts of snow that will receive significantly higher totals, and I am watching that band of snow to your west over Pennsylvania, as it is associated with the disturbance that will come down are merge with the developing low pressure area off of the northeast coast, you will see the snow really begin to pick up, and that retreating band of snow on radar that is moving east will expand very dramatically to the south and west to even reach areas as far south and west as Philadelphia where some snow will occur. Unbelievable snowfall rates are about to occur over southern New England as radar is picking up on extremely heavy precipitation just to the south of long Island resulting in absolutely unbelievable snowfall rates on the order of 4-5 inches an hour with thunder and lightning and this extremely heavy and dangerous band of snow over the next several hours will come on shore of Long Island and move into southern Connecticut and Rhode Island.