GONE WITH THE WIND...
Those lovely 70 degree temperatures we enjoyed a few days ago are what you might say are, gone with the wind. A deep upper air low is situated over the Upper Midwest. As it wobbles slowly through the Great Lakes waves of vorticity will continue to tap cold air leading to a chilly weekend and a flat out cold start to next week.
At 500mb you can see the upper level winds wrapping around the cold core low situated in NC Minnesota.
Here's what the pattern looks like by way of the GOES imagery. The cold air is slowly but surely drilling its way south into the central U.S.
These temperature anomalies show where the cold is centered Monday
Tuesday morning the GFS indicates temperatures 20-25 degrees below normal.
That results in lows Tuesday morning on the GFS that are in the range of 20-25 degrees!
The dark red areas below are where odds of temperatures below 32 are 100 percent Tuesday. That includes the majority of my area.
These are the odds of lows below 20 Tuesday morning. Teens will be seen off to my northwest.
The cyclonic flow will bring bouts of vorticity, one that could generate some isolated showers Sunday and Monday. A stray snowflake or two could be seen, mainly in my northern counties closer to HWY 20. The steep lapse rates will also keep a brisk wind going with wind chills on the GFS in the single digits Tuesday morning. Ouch!
The top analog for cold of this magnitude at this time of year is October 23rd, 1999. You can see the surface and upper level wind pattern with that event below. Many of the top analogs, 2007, 2008, 2010, 1987, 1980 went on to have cold Decembers.
Before the real cold gets here next week, Saturday should see highs in the range of 55-60 and Sunday 52-57. Outside of a stray shower Sunday, most areas will remain dry.
Speaking of dry, that is a trend that will continue around the region for at least the next week, probably longer. The GFS shows this for 10 day precipitation totals. Basically nothing in my area.
The EURO is slightly more generous but not by much. Time to do a rain dance!
The long range pattern the middle of next week does show some warming, something that is to be expected with the MJO entering phase 6. However, I suspect that is a short term thing limited to 5 or 6 days. My gut tells me that western ridge is going to be a force going forward. I expect cooler weather to return in short order. I have solid reasons to believe winter comes earlier this year than it has in quite some time.
That's the long and short of it for now. Enjoy the weekend and the fall colors that will peak in the coming 1-2 weeks! Roll weather...TS