Tuesday, November 29, 2011

Weekend Winter Storm In the Making for the Plains...

In a "teaser" post yesterday evening, I showed the following image, depicting the GFS computer model forecast of snow accumulation across the central and southern Plains by 12 Midnight CST this Saturday night / Sunday morning:


Fast forward to today at about the same time, and here is what the latest run of the same computer forecast model shows for the same valid time of 12 Midnight CST on Saturday night / Sunday morning:


As you can see, the model has shifted the snow band Northward, now running from northeast New Mexico across Kansas instead of across the Texas Panhandle and northern Oklahoma.


At this time, there is still considerable uncertainty as to exactly where the rain vs. snow line is likely to set-up this weekend, but the model consensus has clearly shifted Northward over the last 24 hours.  If this trend holds through tonight and early tomorrow's computer model runs, we'll be able to speak much more confidently as to what is likely to take place - so stay tuned for a more detailed update (including regional impact maps) tomorrow.  


Until we are able to speak with greater certainty on this event, folks all across the region from eastern New Mexico across the Texas and Oklahoma Panhandles, Kansas and northern Oklahoma should monitor the development and progression of this system and stay tuned for later updates...


Meanwhile, colder than normal weather still appears likely for much of the lower 48 United States through most of next week, as shown by the latest GFS computer model temperature anomaly forecast below (blue and green shaded areas indicate below normal temperatures):




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4 comments:

Wendell L. Malone said...

The blocking that has been going on this fall is breaking down...giving the models fits, and no doubt many a forecaster across the Desert Southwest and surrounding states. Going to be fun watching this one, that's for sure.

Rob In Texas said...

Wendell, you hit the nail right on the head! I'm gonna take a serious stab at it tomorrow.

We'll see what happens...

Thanks again for the comment!

Rob

Anthill_Goddess said...

Our local people just said this morning, "Two to three inches, probably, for Southern Iowa..." so I looked at my husband and said, "We'll get snowed-in this weekend...we need to hit the store Friday." *Laughs*

I'm actually looking forward to getting some more snow...I really enjoy winter!

Rob In Texas said...

Anthill, I'm sorry, but I've forgotten exactly where you live. I try to keep up with that in a better way for my regular readers. If you want to e-mail me with your location I'll be more specific in a reply.

In general, at this time, it appears that the Northwestern one-half of Iowa will have the greatest impact (snowfall wise) from this storm. I would put heavier (4 inch plus) snow Northwest of a line from Shenandoah to Waukon the way it looks right now...

A narrow band of ice may take place immediately to the East of the heavy snow line, which could edge into the central third of the state (running Southwest to Northeast). We'll have to keep an eye on that. If the colder air comes in fast enough, this wouldn't be a great threat.