Thursday, December 20, 2012

Christmas Snow Chances

3:10 PM... Video update showing 3 different computer models for next week.  Enjoy.

As we thought, high thunderstorm winds were the main threat last night, but it appears a brief tornado did touch down just southwest of Sheridan.  As I write this, a rating has not been assigned to it by the National Weather Service.  The winds behind the front have been absolutely incredible gusting to 40-50 mph across most of Arkansas with almost 40 thousand without power as of 10AM Thursday morning.  Think this pattern is active and wild now?  It looks to continue.

The models have a little better agreement, but not much run to run consistency.  While the forecast confidence is still on the low end, the good news is that the severe weather threat Christmas day is looking very low.  That of course can change depending on the track of the low.  The 12Z run of the GFS and the 00Z run of the European model both shows the upper level system moving over Arkansas late Christmas day into Wednesday morning.  This would change the rain to snow depending on surface temperatures.  I urge caution here because the 6Z GFS had NO precipitation whatsoever across the state, but the next run changed.  That's why this forecast is still low confidence.  This still has plenty of potential to change.  

Here are the model maps I want to show.

This is the 12Z GFS showing the surface low well southeast of the state at midnight on the 26th.  This would greatly limit any severe weather around here if it's right.  The blue dashed line is the rain/snow line.  (at least a good indicator depending on surface temps as well).  The upper level storm is over AR and those green areas are precipitation which is more than likely wintry!  Look at the black closed line over the Dakotas.  That's cold Canadian high pressure funneling in a cold northeasterly wind into the state.
And this is the European valid at 6AM on Wednesday the 26th.  While not exactly the same as the GFS, it does show the surface low tracking south of the state as well.  Great for snow lovers and this would also diminish the severe threat.  The upper level low is moving into the region with rain changing to snow across most of the northwest half of the state depending on surface temperatures.

I will not go out on a limb right now and say either of these solutions will verify until there's greater run to run consistency, but as you can clearly see here, there is hope for snow.  This isn't a done deal by any stretch of the imagination, but let's keep hope alive!!!!!!!!!!


Anonymous said...

Very good job Todd of breaking the maps down.... You are the only meterologist in Little Rock who takes this much time to explain the possibilites.. Thats why in my opinion your the number 1 meterologist in Little Rock and all of Arkansas... Lets all hope we can get snow in january and febuary....

Will said...

Well here's my input, fwiw. The GFS model is showing some unusual consistency with the last 3 or 4 runs as well as the EURO having a very similar pattern. Cold looks to be pushing south as HP ridging start to build out west and forces some of that Alaska cold southward. At the same time there should be a storm system sneaking along on the southern edge of that cold. Latest EURO indicates snow in northern LA and most of Mississippi so who knows and as the great SnowBirdBob says, we shall see. Things are definitely looking up for us snow lovers. January should be rocking.....

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