Terry’s Take: Bitter cold lurks on the horizon

Posted on: 10:41 pm, November 26, 2013, by

Terry Swails Weather Blog

A BITTER BLAST OF COLD? The writing is on the wall according to the long range forecast models! I’ve been looking at the ensembles off the GFS and EUROPEAN the last few days and brother (or sister) they look cold. I’m going to start with the European models forecast of 500mb jet stream heights Dec 5-10th. Cold air is pouring out of Alaska and the Yukon creating an area of below normal heights that covers much of the NW 2/3rds of the United States. That opens the door wide for the delivery of Arctic air masses to the country!

1 EURO HT ANOMALY

1 EURO ANOMALY
Look at the EURO temp. anomaly Dec 5-9th. You can clearly see it is promoting a bitter cold Arctic blast that is just entering the the Midwest. Switching to the GFS and going a step further, its temp anomaly December 6th show temperatures 48 degrees below normal!!!

1 GFS DEC 6TH

That is off the proverbial charts. MEGA cold that could rival records.
I was wondering about other serious cold air outbreaks in December and how this situation might compare. To the rescue came Joe Bastardi of Weatherbell. In looking at other frigid set-ups he was able to analog what todays models are showing to similar occasions in the past. The closest analog he came up with was December 1983. Look at the 500mb jet stream heights I posted and compare them to what is forecast on the EURO Dec 5-10th (first graphic). Focus on the colors, the warm heights in red and cold heights in blue of 1983 are nearly identical to what is forecast. I don’t have to tell anybody that lived through the Christmas of 1983 what a brutal stretch of weather that was….I’ll remind you in a moment.

1 1983 ANOMALY

1 DEC 24-28TH
What this all points to is that the evidence is strong the Midwest is headed for what could be a very cold 2nd week of December. I would also look for some part of the Midwest to pick up snow in advance of the surge. Exactly where is too hard to nail this far out. More on that in future forecasts.

Now, that little reminder about the deep freeze of Dec 25th, 1983. Bitterly cold weather set in for nearly a week leading up to Christmas with the worst conditions experienced on December 23-25, as temperatures were rarely above zero and howling winds created very dangerous wind chills and deep snow drifts making travel all but impossible. For the four days from December 22-25 the statewide average temperature was -12.5 F which is the third-coldest such stretch on record in Iowa. The coldest reported temperature on Christmas morning was -28 at Cascade. Even during the afternoon many areas failed to climb out of the teens below zero including high temperatures of -14 F at Sioux Rapids. The month finished as the coldest Iowa December on record. In the Quad Cities the low on the 24th was a record -19. The high Christmas day a record cold low max of -2. Wind chills to 50 below were common! Even Santa Claus complained about the cold that Christmas!

1 dec 83 map