Polar Plump

Good Monday morning. It's cold at my place right now. 32 degrees, but at least doubling that by this afternoon. Therefore, I'll be outside cutting back some plants and taking advantage of this brief window of opportunity before some serious changes go into effect later in the week.

We have a blast of truly Arctic air poised to plunge into the heartland of the U.S. In fact as I write this post, snow is breaking out across the northern parts of the Plains and Midwest in advance of this Polar air mass. Minneapolis is expecting up to a foot of snow from this system.

By the way, the Weather Channel has named the system Astro...yes, the dog from 'The Jetsons'. I don't know why. Whatever.

 
Source: cybercomm.nl

Nevertheless, by the middle of the week, our temperatures here will have transitioned and will not bottom out until sometime Friday morning. I'm expecting low temperatures for several locations in the 14-19 degree range, if we have enough clearing and calmer conditions. And I still think there is a chance that some areas may not get above 32 degrees on Thursday for high temperatures.

Some may have forgotten that last November we had a stretch of very cold readings here in Kentucky. Louisville made it to 32 degrees on November 24 followed by a couple more days in the 30's. Lexington only made it to 30 degrees that November 24 and had a 1" snow depth on the 27th.

I want to show you something....Take a look at the graphic below. This is from the middle of the month last year and what the Climate Prediction Center was expecting for the following several days. You may not understand all of the lines and numbers but the northwest and northeast show some serious blocking (note the red lines).

11/13/2013 500-millibar anomaly map

That blocking allowed cold air to funnel into our area and produce the very cold readings. However, the west coast basked in relative warmth.

Now, let's take a look at our current graphic....

11/09/2014 500-millibar anomaly map

A similar pattern. However, the above normal anomalies across the Arctic allow cold air to drop south because the polar jet stream winds are more relaxed and buckle thereby providing a viable highway, destination all the way to the Gulf Coast.

In other words, this cold spell will be much stronger and more broad than last year's outbreak. In addition, it may last longer. Until the blocking pattern eases, expect more cold air intrusions on into the holiday week. That's at least 2 weeks!

This could be a record-setting month for cold. Now, if we can only get some snow into the forecast...hmmm, more on that at another time.

MS