We've started meteorological fall which means Winter is getting closer.
I've been posting these little winter thought for the last couple of months This is something I'm probably going to continue to do. so This will be a large part on how the winter outlook work this year.
Over much of the summer, there was a lot of heat with several heat waves impacting our region. But for the last few weeks we have been coolish here in the Northeastern and Middle Atlantic regions of the US.
The reason for this Has been the ridgeing we've seen over western North America and troughing over the eastern half. This has allowed cold air to drift out of Alaska and northern Canada and fall into the US.
The polar vortex:
The polar vortex is a large area of spinning air (Vortex) that spins over the north pole. Typically spins in a counter clockwise direction, making it generally stronger. It typically weakens a lot during the summer and then reemerges as we get into fall, right around this time of year. The polar vortex has a big impact on our winter into spring pattern.
When the polar vortex is strong It typically locks out the cold arctic air over and around the north pole. But when it gets weaker We typically see a lot more variation In the portal vortex Which leads to outbreaks of cold air dropping into the lower latitudes.
What's going on with the polar vortex right now?
We've had warming in the stratosphere the last few months. This has kept the polar vortex weaker this year, as it interfered with the overall pattern.
The Quasi-Biennial Oscillation (QBO) is currently negative, which is causing the stratospheric winds to be easterly. This is also helping to weaken the polar vortex; as it reverses the direction of the polar vortex thereby causing it to weaken.
Sea Surface Temperature:
Current global SST's
El Nino Southern Oscillation.
We are still under an official la Nina watch.
This is showing a strong likelihood for generally overall below average temperatures for the upcoming winter.
The Eastern Pacific Oscillation (EPO) and the Atlantic Oscillation (AO) are going negative. This is also A cold signal not only for this fall .But it also shows the pattern Heading into winter could feature high pressure blocking and more cold outbreaks
Image credit Weather bell
The first half of September is looking to be quite chilly with below average temperatures.
Image credit Tropical tidbits
The Climate Prediction Center (CPC) 6-10 day temperature outlook does support this idea of cold over the eastern US.
This general troughing is going to stick around across the eastern continuous US at least for the next couple of weeks.
2 meter temperature anomalies
Image credit Tropical tidbits
That above average high pressure sitting over western Canada. Is going to create something rare for September, we're going to see a cross polar flow direct colder air into the eastern half of the United States. A cross polar flow pattern is something we normally see during the winter; The reason for this is typically our pressure systems are stronger during the winter than they are during the summer.Looking at the temperature anomaly map we can see western Canada sitting under the high pressure ridge. This helps direct that much colder than average air down into the central, southern and eastern United States.
Looking at the extended range on the GFS, the same overall general pattern of high pressure ridging out over western Canada and some troughing in the eastern US looks to continue. Extended range models tend to average out everything the further out you go. So they kind of mute the overall look of the pattern. As we get closer the ridge and trough effect could become more profound. I don't think the second half of September is going to be as overall chilly as the first half, here in the Northeast and northern Middle Atlantic.
Image credit Tropical tidbits
The polar vortex is very weak right now. In fact It's at record weakness for this point in September. With the vortex so weak, we could see a lot of variations leading to cold air outbreaks as we head towards meteorological winter which begins on December 1. The pattern does favor frequent cold fronts moving across the CONUS. So fall 2025 could feature more than a few cold outbreaks as we move forward. What does this overall pattern hint at for the upcoming winter?
Current thoughts about this upcoming winter:
With the polar vortex Start now fall so weak It's implying at least to me that we could see a highly variable polar vortex During winter 2025-2026.
The upcoming winter is looking to be quite variable, with the northern half Of the US averaging quite cold and wet, with the southern half of the US being very mild and dry.
If this does end up being the case it could mean the Ohio Valley, across southern Pennsylvania into southern New Jersey, Maryland and Delaware end up being in the battle zone with an active storm pattern. The risk for ice storms across this part of the region would be much higher than average.
The current setup of the pattern and the way it's looking to evolve Means this winter could see quite a few Clippers.
We could see more in the way of Nor'easters than we've seen in the past 5 or 6 winters.
This would imply that Maryland, Delaware, New Jersey, Southeast Pennsylvania up through Southeast New York state, across southern and eastern New England from Boston to Maine would have a good chance for a very active winter.
The pattern that looks to be setting up looks to be very favorable for lake effect snow. Like last winter, the lake effect snow belts could be pummeled by quite a bit of snow.
The first half of winter (December into January) could be a bit mild. Then the second half (February and March) could be very cold and stormy. Because, winter could start with a predominantly positive NAO and ends with a primarily negative NAO.
I Love Winter but too me December and January are Winter,Years ago the cold and snow started in November.I was always tramping through the woods on my Birthday with snow on the ground and many days in the air.My Birthday is November 13 and so many days the cold was harsh.When we left Vt. to come home the snow pack was close to 3 feet and temperatures were close to zero at 4am and only rebounded to 15-20 during the day.Home had a little snow on the ground when we left but there was more when we came home to tramp around the woods of Mass until the new year.There were many days below 0 well below 0.The bonus was we always had a White CHRISTmas.That was how I learned too like an early winter.February is a short month and the sun is getting higher in the sky" A mild December and January means no White CHRISTmas and that Ice is not forming on the ice,so February when the derbies are held they are canceled due to low ice.I don’t think we will ever see a cold and snowy 15 days in November again,and December has been mild and rainy as of late.The question I have is that November used to be Winter like and December was always White and Cold.Does it take extra time too cool off the Northeast due to the SST getting so warm and the Cold air takes longer to get here from Canada.Southern Canada seems to be much milder in November.I don’t know anywhere near as much as you but has the Earth lost too much Summer Ice and the Cities are bigger therefore,less trees,more black top,more concrete.We had some cold air outbreaks last year but -12 although cold is not -20,-30,certainly not -35 which is the coldest it has ever been here.At least since I’ve been able to read a thermometer.Has that type of cold been taken away forever.
ReplyDeleteI did answer below
DeleteYes generally overall Warmer global oceans here in the northern hemisphere are leading to meteorological swings in temperatures as well as overall storm storm potency and more volatility in the storm track. As we move along Winter whiplash is going to continue. As you point out The urban heat island effect and less in the way of trees help promote a warmer climate as well. The overall warmer conditions mean that we see more rain events than snow events also many times the winter storms don't last as long. Our spring and summers are also becoming warmer. But winter temperatures are seeing the most change and variability, especially here in new England. The other point you mentioned about the last ice in the arctic along with less general snow cover Is also affecting the polar vortex Tending to weaken it and make it more prone to variable conditions and more stretching into the southern Latitudes more often. But no two winters are the same and like this winter we've seen above average snowfall over Greenland and across northern Canada than we saw last year and even over last couple of winters. But this kind of pattern is becoming less common. There are different opinions on why the globe and oceans are warming. I've posted my reasons for it many times in the various blog post I've done on the subject And how in my opinion Human Kind has less input on to this warming climate than many others may think. If I'm right Then at some point in the future This will change back to a colder pattern How long it takes But it could be quite Sometime before that happens.
ReplyDeleteI read somewhere that weather is cyclic.Back in the 1900's the early 1900's the Weather in the Northeast was very cold,then it was not as cold and sometime after a few winters that were cold and snowy it became mild for a few winters.I don’t know how long it lasted or how mild but it went back to normal.There were winters that were very cold but there was not much snow,less than 20”.Back then the forecaster’s did not know what you know now.They may not have known about the things that help to control the weather,you know the things that have all the abbreviations.I can’t remember them all but I remember some.They may not have known that what happens in Alaska,helps determine the weather here.There are many other things that are important but I don’t know Them all.
DeleteIt's time for wet, sloppy winters to end again. We haven't seen 100 inches of snow in eastern NY for years. Thank you for the information on your site.
ReplyDeleteYou're welcome
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