Snowstorm over upper midwest, snow coming for the NE Appalachians. Longer range pattern suggests a large warm-up for the US after October 10th. My ideas continue for US tropical troubles in October

As many other weather advance forecasters have been touting, snowfall will be be occurring over the upper midwest and northern Rockies, specifically Northern Minnesota and North Dakota tomorrow. Snow is already falling over parts of South Dakota and the Black Hills, and this snow will spread NE towards North Dakota and Minnesota. Snow totals will probably exceed 8 inches in many areas NE of Grand Forks, and the snow will be blowing and drifting at times, and according to the local NWS office out of Grand Forks, ND, sustained winds will be ranging from 20-30 MPH, with gusts potentially exceeding 40 MPH, which would make this, by definition not quite a blizzard, but very close to it. (A blizzard is defined as a snowstorm with with winds of at least 35 MPH, and visibility less than a quarter mile for a period of at least 3 hours. Many of the impacts felt over Northwest MN and NE North Dakota will be blizzard-like, and it certainly will make travel very hazardous to nearly impossible at times.

Along with this weather system, there is another shortwave area of low pressure that will develop within this main trough of low pressure near the northern Rockies in a few days, and this will combine with energy near the tail end of a cold front that will be associated with this low pressure system that will produce snow over the upper midwest tomorrow, and will lead to the formation of a new area of low pressure. This new area of low pressure will move south of the I-70 corridor and off the New England coast in several days, and with cold air that will be coming into place from the low pressure that’s now over Montana, it is possible that some wintry precipitation may fall into the Pennsylvania Appalachians and areas northeastward into Quebec. However, the amount of cold air that will be available with this system is still in question, and it appears that 850 millibar values will be ranging from 30-36 degrees, which will not be too supportive of snow in the lower levels, but in elevations exceeding 1500-2000 feet, the air will be colder and snow may be able to fall and accumulate in some areas that receive more intense rates of precipitation. Regardless, much colder air will settle into the region, and widespread frosts and freezes will occur over the Northeast, Appalachians, and areas of the Great Lakes behind this low pressure system, and will put an end to the growing season over these areas.

GFS 850 millibar heights not very supportive of snowfall, with values near 0 over the northeast, which translates to surface temperatures around 35-39 degrees. However, in the higher elevations, especially at 2000 feet and above, it may be just cold enough for snow to fall.

The pattern that has helped to produce these early season chances for winter weather has been very favorable for large troughs over the eastern and central US, and is a pattern that is classic for large cold shots into the the eastern and central US, with a large ridge extending from the Gulf of Alaska and into NW Canada. Such large high latitude high pressure areas force areas of low pressure and troughiness over the US, especially east of the Rockies, and near the Hudson Bay. In this instance, this large area of general low pressure focused over the Hudson Bay and eastern US has forced blocking high pressure upstream just south of Greenland and Iceland, and when you have higher than normal pressures near Iceland and Greenland, you have a -NAO, and this -NAO has only amplified the effects of this cold air mass east of the Rockies.

This pattern of course can be drawn back to the Western Pacific landfall typhoon theory that was proposed by Joe Bastardi, and has been something I have taken and ran with the past several days, because now with another large trough over the eastern US, one only has to look to the Western Pacific to see that we have yet another typhoon currently near Japan. When you have a landfalling typhoon over the west Pacific, it strengthens the trough over eastern Asia, strengthens ridging over extreme eastern Russia, which in turn amplifies a low pressure area near the Bearing Sea, that forces higher pressures over the Gulf of Alaska and western North America. When you have higher than normal pressures over western North America, it forces lower pressures and a trough to dig in over the eastern US, and the troughing over the eastern US helps to enhance a colder than normal airmass, and increases the chances for winter weather.

Notice the typhoon over Japan, which supports a troughing pattern over the eastern US. Also notice the large area of cyclonic motion towards the bottom of the picture, that is the monsoonal low which is being enhanced by the upward phase of the MJO. This monsoonal low could spin off yet another typhoon in the next several days, which would suggest this cold and unsettled weather pattern over the eastern and central US will continue for at least the next 7-10 days.

The GFS model showing yet another western Pacific typhoon, and you can see this amplifies the trough over eastern Asia, pumps ridging over the Gulf of Alaska, and that ridge over Alaska helps to promote a trough centered near the Hudson Bay and central-eastern US. Also notice the ridging near and just south of Greenland/Iceland, this a -NAO signature.

In the longer ranges, it appears that yet another typhoon will form over the western Pacific and head towards Japan in several days, and that means yet another trough over low pressure will dig over the eastern US in about a week or so, and that trough will keep the weather unsettled and rather chilly east of the Rockies. However, there are signs that this pattern may finally break down once and for all thanks to the MJO finally starting to move out of the “igloo” and it may continue to move out of octants 5 and 6 towards Mid-October. If this does occur then a major pattern flip would unfold over the Northern Hemisphere, because as I have said in previous posts, with the MJO moving out of the western Pacific, that will raise the pressures over the Western Pacific and begin to focus low pressures over the Gulf of Alaska, and with low pressure near that area it bundles the cold air way up to the north, and it pumps a ridge to its southeast over the US and southern Canada, thus leading to warmer weather.

The NAO will likely remain negative for a while, but when the MJO moves out of the Western Pacific, this will flip the pattern over the Northern hemisphere. With the 500 millibar heights potentially changing over the northern hemisphere, this would support a change to a +NAO, and more warmth over the central and eastern US.

The GFS model showing what will happen when the MJO moves out of the Western Pacific, the pressures begin to rise over that area, and lower pressures are focused over Alaska and NW Canada, which is the opposite of the pattern we currently have in place. Also notice the lower pressures over Iceland and Greenland, this is a +NAO signature, and this would further support my ideas for warmth over the US after October 10th.

Even though the predictions for the MJO have been very unreliable, notice how the MJO has finally began to move, and is showing signs of eventually moving out of the Western Pacific, this would greatly effect the pattern over the Northern Hemisphere.

With this pattern change, we now have to be more concerned about a potential comeback with the hurricane season, because with these large cold air masses and with high pressure showing up over the US in the longer ranges, this means that with higher pressures over the United States it forces convergence and rising air over the SW Atlantic, Caribbean, and Gulf of Mexico, which would be favorable for tropical development near the US just like in the beginning of the hurricane season. With systems developing much closer to home, it also increases the chances for a landfall simply due to the fact that storms will developing much closer to land, and with wind shear and dry air increasing, and with the african wave train beginning to subside, conditions will continue to deteriorate over the deep tropical Atlantic, as they usually do in October, and this will help to focus tropical activity farther west.

The ECMWF 12Z model run with 850 millibar vorticity showing the higher pressures over the US helping to force convergence over the tropics, and this expresses my concerns for a tropical threat for the US in October.

Eric

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.

18 comments on “Snowstorm over upper midwest, snow coming for the NE Appalachians. Longer range pattern suggests a large warm-up for the US after October 10th. My ideas continue for US tropical troubles in October

  1. Thank you Jason, I think we will be 10-15 degrees above average across much of the US, with temps probably well into the 60s all the way to the Canadian border with 70s getting north of the I-80 corridor. The south will be warm as well, although not as far above average as the midwest and northeast, 70s will be fairly dominant over the south, very nice October weather, even some 80s possible generally south of I-20 corridor. The western US will not be quite as above normal as they are now, probably near to just below normal temperature wise from the Rockies and points westward. Also, the Pacific Northwest will become quite unsettled compared to what they have been seeing of recent.
  2. Although this sure does make a lot of sense,i do see more ridging near greenland and i am personally skeptical of the MJO for it does not seem to be the main factor for me in this situation. With convection being generally normal or slightly weak i do see future troughs being less strong than whats to occur this weekend. Now that you’ve redirected to me to a different view i do see temps ranging from average to slightly above later in the future. 10-15 seems a little to much but i can be wrong lol. As for the NAO i just cant see it going positive the highest i see it going is slightly neutral. Respectfully a fan Jason lol
  3. Well, that is probably going to be the case over the midwest, the South will probably be closer to 5 above normal or so. Now, I don’t agree with you about the MJO not being a big player in the northern hemisphere atmospheric pattern.The MJO is clearly one of the main, if not the biggest player in the northern hemisphere atmospheric pattern. Why? Well, considering that the tropics have the most heat energy compared to the other two main global climate zones, because the energy differential between 1 degree F at 80 degrees F is the equivalent of about a change in temperature of 15 degrees at 0F. Now, when you compare the atmosphere potential energy to the oceans, the oceans is 1000x greater. Combine these factors together, and now we are looking at the tropical oceans for potential changes in the pattern, and we have three ocean basins to look at the Atlantic, Eastern Pacific, Western Pacific and the Indian Ocean. Well, when you look at all of these oceans and compare between them for which ocean basin has the highest amounts of TCHP, (the same thing as saying which ocean basin has the most potential energy) the Western Pacific wins hands down. Now, when think about the Western Pacific typhoon theory that was proposed by Joe Bastardi, it makes sense, look at the tropical ocean basin with the most TCHP, and take note of trends in the western Pacific to the US. When you do that, you’ll notice how when there is a typhoon recurve or landfall in eastern Asia it translates to a trough over the eastern US, and when you’ve taken note of that trend, now you should start to look for reasons why there is a hurricane over the Western Pacific, (what’s driving the tropics). The MJO is clearly a large driver of the tropics, and it has been its upward phase over the western Pacific for several weeks, and during that time, the eastern US has seen several large troughs and much colder conditions than normal. Now that you know that the Western Pacific is the main driver of the northern hemisphere pattern, you look for what drives the western Pacific, and that is the MJO. If you know how the MJO affects the tropics, and where it will be in a certain period of time, you can make a very accurate long range forecast, which is what I have been doing over the last few weeks, and so far my forecasting has been quite accurate, so I must be doing something right huh?
    As far as the NAO, I think that if we see the MJO move out of the Western Pacific, it will flip positive, at least briefly, because when the MJO leaves it will flip the atmospheric pattern, by raising the pressures over the Western Pacific, it will lower the pressures over Alaska, force more ridging in the US, and help to induce more low pressure upstream towards Greenland and Iceland, which is a -NAO pattern and the exact opposite of what we are seeing now.
  4. Correction: “+NAO” Sorry, I couldn’t chat with you Jason, I busy was typing up this post at that time, but I’m very glad you appreciate my insight and are a fan of mine, lol.
  5. @ Dustin of course I do, this warm-up would be temporary, and even good winters have significant warm periods at some point or another, it can not stay cold for the entire winter, but overall this winter will be colder and snowier than normal. Out of the entire US, if I had to pick one area that would see a cold and snowy winter, it would be the mid-atlantic states and parts of the south including, but not limited to, Georgia, Alabama, the Carolinas, Virginia, West Virginia, Maryland, and up into southern PA and NJ. That does not mean other areas won’t have a good winter, it just looks like the mid-atlantic stands the best chance to see a cold and snowy winter.
  6. @ Jason Lol, I feel you, I think we’ve all felt that way at some point or another, let’s just see if these new predictions I have are right about the hurricane threat in this month and the general warm-up coming after October 10th.
  7. how long would the temporary warmth last and when do you think the mjo will be back in the western pacific.

    does your prediction on oklahoma’s winter still stand because accuweather really didn’t say anything about what kind of winter oklahoma would have.

  8. @ Ahmad this temporary warmth will probably not last too long for the southern US if the MJO starts to move towards Octants 7 and 8. The warmth we will see will more likely be in response to the rising pressures over the western pacific, and once the pressure rises begin to slow, we will probably begin to see things cool down some over the US. I would anticipate that if the MJO forecast holds for it to leave the western Pacific in 10 days or so, then I think this warm-up would come to an end relatively quickly over the southern US, but this may not be the case over the northern US, especially the northern plains and New England. The pattern being suggested by the long range models appears reminiscent of a warm PDO el nino pattern, where we have the active subtropical jet being enhanced by the warmer than normal central and eastern pacific equatorial waters. When you combine this with an upward MJO pulse that appears likely to move towards the eastern pacific and western Atlantic, this will enhance lower pressures over the tropics and the southern US, which will be being affected by the subtropical jet stream. When you also take into account the fact that raising the pressures over the western Pacific will help to enhance lower pressures near Alaska, which will amplify a ridge over the US, and forces low pressure to become energized downstream towards Greenland and Iceland, which would be a +NAO. I am much more concerned about this pattern bringing a tropical cyclone threat than I am about any warm-up, because when you combine an upward MJO pulse with high pressure over the Canadian Maritimes and New England, you force convergence over the SW atlantic, and with an active subtropical jet stream, you’ll focus an are of general pressure inland over the southeast. This type of pattern would suggest that any system that forms would head towards land, or at least get close to it, because tropical cyclones naturally take the path of least resistance, and when the lower pressures are over the SE US, then that’s where they would go. However, considering how unpredictable and varying the MJO has been of late, if the MJO somehow remains in the western Pacific in 2 weeks time, then my entire forecast for a warm-up after October 10th is completely garbage.
    The winter in Oklahoma will definitely be much better than last year, and I would expect above average snowfall for Oklahoma, and some early-season snows in November and December towards the Oklahoma Panhandle. I think the biggest concern for you this year will be ice storms. Since you’ll be stuck in between the trough over the east, and general ridge out west, temperatures will vary, and with the subtropical jet being more active, this means that once low pressure areas begin to leave the high terrain of the Southwestern US and enter the southern Plains, with lots of energy coming from the Gulf of Mexico, and cold air being supplied by the polar jet digging southward into the eastern half of the US, we may see rapid cyclogenesis in some cases. When you have low pressure areas that are strengthening quickly, he dynamics within them can be dramatic, and with this in mind, it can be very easy for warm air to be trapped aloft in the mid-levels of the atmosphere, despite surface temperatures being below freezing, which is the reason why ice forms in the first place.
  9. when you say above average snowfall does that mean for my area even though the main threat will be ice storms
  10. Yes it does, look, even though you may see many more snowstorms than ice storms, I think they will be the main threat because ice storms are so much more destructive and disruptive than snowstorms, and the fact that I think the southern plains into AR, LA, West TN, KY, AL, and MS, will be the main area to look out for ice.
  11. @ Jason, I have taken note of that, but the -NAO in this case would appear to be weighted towards Europe and Asia, because just east of Greenland and over the Canadian maritimes, pressures will be lower, which will force predominant riding over the eastern US, which would be a warm pattern despite the -NAO. Also, I;m taking note of the MJO, because it does appear that it may move towards octants 7 and 8 in a few weeks, and with high pressure over the eastern US forcing convergence over the tropics, combined with an upward MJO pulse, it would make sense to have a hurricane threat on the US in October, which is a forecast I’ve had since September 22nd, and it finally looks like the models are starting to pick up on this threat, here’s the link to the GFS which shows a deepening hurricane over the western caribbean, with a trough over the Gulf of Mexico ready to drag it northwards in the general direction of the US. http://raleighwx.americanwx.com/models/gfs/12zgfstropical850mbVortSLP360.gif
    Now look at the pattern I’ve been talking about with ridging over the eastern US, forcing convergence over the tropics and lowering the pressures. If this happens, considering how high the TCHP and SST are, with proper ventilation and anticyclonic motion being enhanced by an upward MJO, I’m being lead to believe that this may be the biggest tropical threat of the season at hand, I’m especially concerned for the eastern Gulf of Mexico (west coast of Florida in particular) and the Southeastern states, also as the model progresses, also taking note of more tropical activity showing up in the western Pacific, and with all of that high latitude blocking, and with the fact that usually, when the MJO is in octants 8,1, and 2, it is usually a cold pattern for the eastern US. Considering all of this I would say that any warm-up we see after October 10th would be temporary, and there are a few early hints that the end of October may be very cold for areas east of the Rockies. Here’s the link to the GFS 500 millibar anomalies, notice how this fits the description of the hurricane threat pattern I have been talking about since September 22nd. http://raleighwx.americanwx.com/models/gfs/12zgfs500mbHeightAnomalyNH252.gif

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