We are seeing the ECMWF and GFS models pick up on some major stratospheric warming.
As a pre-note, the images we show you are the examples as close to the 100mb level that we could find. Keep in mind that levels above the 10mb images we are about to show will experience more significant warming than what we are showing. It's all about if the warming occurs closer to the 100mb level.
Is the Pattern Change right around the corner?
In the first image, we are seeing the analysis of the stratosphere from the ECMWF model. At this point, models do not matter as it is only an analysis. Notice how abundant the cold air is in dark blue as we see a deep low pressure system forming a deep vortex around the North Pole, keeping the cold air in. This technically is a signal of how strong the Arctic Oscillation is. When the AO is positive, there is a strong vortex holding in the cold air way up north in the North Pole, as we see in the analysis. The AO is in a positive phase right now, so we are apparently seeing the AO in action.
Skip ahead 10 days. The second image is for the North Pole at the same 10 millibar stratosphere level as was in the analysis, but 10 days out in the forecast. We now see a building ridge and warmer temperatures trying to force their way northward into the North Pole. It is being forced northward, rather than simply bumping around, as we can see the very tight isobars where the blue and light orange meet in the little crosshair symbol. The strong low pressure remains in place, but the coldest air and the low itself have been displaced more southward as a result of the pressing warmer temperatures. If these warmer temperatures are able to eke out their place in the North Pole and effectively kick out the deep vortex, we would see a negative AO and NAO, both of which would contribute to snow and cold over the East US. However, looking back a few days before this 10 day forecast, I found that these warmer temperatures are actually moving westward in a square dance-like routine. The warm air mass is weakening, but the deep cold is eroding as well. Notice the weak warming in the lower portion of the graphic. We find this weak warming area to also be moving in a circle, in similar fashion to how the main warming area is moving in a counter clockwise circle around the deep cold region.
What does this second, weaker warming area mean? If this second warming area comes to verify, it would be getting stronger as it moves counter clockwise. This would mean that there would be two warming regions attacking the deep low pressure and cold in the North Pole region. It does appear that these two warming regions are having an effect on the deep low. The question is will the low be displaced enough for the warming regions to take over control, effectively changing the pattern into a cold and snowy one? We aren't sure, but here's a reassuring piece: Notice the very weak, disorganized warming area on the upper part of the initial 10mb stratosphere analysis image. That warming area actually becomes much stronger and is the same warming section that we see in the 10 day forecast, with that warming section still in the upper-middle part of the image. The fact that the warming area forecasted in the 10 day forecast is currently present is reassuring news, as it signals that the piece required to 'damage' the cold regime in the North Pole is already there in the analysis.
Stay on the lookout, snow lovers. This could be the break you have been waiting for.
On a side note: Reputed meteorologist Tom Skilling in Chicago put out an article today, noting how at least a couple winters with comparably low snowfall to this year turned into above normal snowfall with a very back-loaded winter. This could mean that the back end of the winter will be 'vindication', so to speak, for many forecasters' forecasts (including ours).
Have a safe and happy holidays. We will not be publishing posts for much of Christmas Eve and Christmas Day.
As a pre-note, the images we show you are the examples as close to the 100mb level that we could find. Keep in mind that levels above the 10mb images we are about to show will experience more significant warming than what we are showing. It's all about if the warming occurs closer to the 100mb level.
Is the Pattern Change right around the corner?
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| Initial 10 millibar Stratosphere Analysis |
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| Forecast 10 day temperatures at 10 millibar level in the Stratosphere. |
Skip ahead 10 days. The second image is for the North Pole at the same 10 millibar stratosphere level as was in the analysis, but 10 days out in the forecast. We now see a building ridge and warmer temperatures trying to force their way northward into the North Pole. It is being forced northward, rather than simply bumping around, as we can see the very tight isobars where the blue and light orange meet in the little crosshair symbol. The strong low pressure remains in place, but the coldest air and the low itself have been displaced more southward as a result of the pressing warmer temperatures. If these warmer temperatures are able to eke out their place in the North Pole and effectively kick out the deep vortex, we would see a negative AO and NAO, both of which would contribute to snow and cold over the East US. However, looking back a few days before this 10 day forecast, I found that these warmer temperatures are actually moving westward in a square dance-like routine. The warm air mass is weakening, but the deep cold is eroding as well. Notice the weak warming in the lower portion of the graphic. We find this weak warming area to also be moving in a circle, in similar fashion to how the main warming area is moving in a counter clockwise circle around the deep cold region.
What does this second, weaker warming area mean? If this second warming area comes to verify, it would be getting stronger as it moves counter clockwise. This would mean that there would be two warming regions attacking the deep low pressure and cold in the North Pole region. It does appear that these two warming regions are having an effect on the deep low. The question is will the low be displaced enough for the warming regions to take over control, effectively changing the pattern into a cold and snowy one? We aren't sure, but here's a reassuring piece: Notice the very weak, disorganized warming area on the upper part of the initial 10mb stratosphere analysis image. That warming area actually becomes much stronger and is the same warming section that we see in the 10 day forecast, with that warming section still in the upper-middle part of the image. The fact that the warming area forecasted in the 10 day forecast is currently present is reassuring news, as it signals that the piece required to 'damage' the cold regime in the North Pole is already there in the analysis.
Stay on the lookout, snow lovers. This could be the break you have been waiting for.
On a side note: Reputed meteorologist Tom Skilling in Chicago put out an article today, noting how at least a couple winters with comparably low snowfall to this year turned into above normal snowfall with a very back-loaded winter. This could mean that the back end of the winter will be 'vindication', so to speak, for many forecasters' forecasts (including ours).
Have a safe and happy holidays. We will not be publishing posts for much of Christmas Eve and Christmas Day.
17 comments:
What happened to yesterday's post?
Hello Andrew.Very informative article.Let's just hope that this is what's going to change the pattern so the Ohio Valley and east will start seeing snowstorms.Have a merry christmas with your family!!!!!!!!!!!!!!!
Hi Andrew, At this point I give up on thinking this whole winter thing will even happen this year. Fact matter is that if we dont have snow by mid January its just not happening this year. Sad but true statement from my local forecaster.
Merry Christmas!!You gave me a great gift this year.GREAT FORECASTING!!!!!
Anonymous #1: Those pictures were of the 30, 50, 70mb levels. This post is for the 20mb level, which is higher up in the atmosphere and thus more prone to warming.
Mike: If anything, this should indeed change the pattern. Merry Christmas to you and your family, Mike.
Anonymous #2: I'm going to tell you a little something: Local TV weather people aren't as invested into all these indices and this warming as people like me are. Don't get me wrong, there are some great weather people out there, like Tom Skilling. But i've seen some other TV weather people map the wrong calls on snowstorms too early. So I personally would take that with a grain of salt, unless they have some evidence.
AJ: Have a Merry Christmas with your family, AJ. I'm glad I was able to provide such good forecasting for you.
Good morning Andrew.How accurate is the instantweather maps site?The first week on January shows decent snowfall around Ohio at hour 384.Im not too sure if these maps are good to use for forecasting.Are the models you use to predict showing any developement?
The Instantweather maps site is just a site that shows the models. However, it is one of my favorites, as it is one of the fastest updating model site I know of, and has free ECMWF products.
However, Hour 384 is not very reliable at that far out (16 days away).
Hi Andrew. Anonymous #1 here again. I am not referring to the increased warming when compared to two day's ago post, I am referring to the fact that yesterday, you were saying how the winter pattern change would be too little and too late, and now in your latest update you are on board with a back loaded winter. I am wondering how such a change could have occurred. Thanks!
Anonymous #1: Yes, that is the same post I as mentioning. But if you want the reasoning, here it is: We failed to compare analysis' at other levels to their forecasts. When that was done, it was determined that the pattern change may actually come in time. We then picked up on the back-loaded winter piece from Tom Skilling in an article.
Hi Andrew.I just watched my local weather forecast,and he mentioned that the weather pattern may become snowier after the new year.
I am thinking that as well.
Hi Andrew.It goes hand in hand exactly what your saying in this post.Hopefully it happens.It was snowing a few hours ago,but it basically melted as soon as it hit the ground.Ground temperature a bit too warm.
I encourage you to check out the post on how the pattern change is finally starting. It's coming out at 1:00 pM CST today.
Keep wishcasting and I'll keep enjoying my low heating bills. God bless the positive AO and NAO!
The AO and NAO are due to major change. It is not wish casting. Wishcasting has to do with models- the stratosphere is what is actually happening.
I agree with you andrew.That is what wish casting is.Hey anonymous,if you don't like paying high heating bills,move to Florida!!!!!!!!!!!!!!
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