Still Looking Colder at Month’s End

It depended on where you were as the sun rose over the Tennessee Valley this morning as to how cold it was! Fort Payne in DeKalb County and Black Creek in Etowah County dropped to 36º with patchy frost. Huntsville only dropped to 48 degrees while Muscle Shoals stayed at 51 degrees.

Tonight will be colder with lows in the 30s and 40s again! Be sure to click over to WHNT.com/Weather for the detailed forecast through the weekend and early next week. In that forecast, you’ll see there is a warming trend coming through the middle of next week; after that, there looks to be a big surge of cold weather coming south late next week into next weekend. I wrote about that on Monday here: Valleywx.com.

The evidence is growing for a “flip” to much colder weather for most of the East behind a strong cold front that should move through the Tennessee Valley on Thursday or Friday of next week. The timing is a little uncertain, but the cold front definitely looks like the real deal. Cold air will blow in for days after that front passes:

6Z GFS Model Output for 1 PM Sunday (October 28)

For some confirmation on this idea, we turn to the old reliable Canadian NAFES temperature anomaly. When you see a flip like this model has done in the past few days (from above normal to solidly below normal), you know something is up!

Just how cold do we expect it to get? This kind of chilly air mass can push temperatures as much as 5 to 10 degrees below normal across the board. That could spell some lows in the upper 20s and lower 30s for the Tennessee Valley between October 28 and November 2; afternoon highs could be as cool as the 50 and lower 60s depending on how much sunshine we see.

The long-range GENS (American) forecast probabilities suggest temperatures well below 35º in that time frame:

That’s a 57% chance of a morning low under 35º in Huntsville on Monday, October 29th. That’s pretty significant (and higher than the same guidance showed earlier this week)!

The bottom line is that the growing season for a large percentage of the Tennessee Valley may come to an end by Halloween. The normal first frost for us comes anywhere from October 25 to November 5, so this is definitely not an unprecedented cool-down. Record lows in the time frame here are in the lower 20s, and those lows do not appear to be in danger.

-Jason
Connect with me!
Google+: Jason Simpson
Facebook: Jason Simpson’s Fan Page
Twitter: @simpsonwhnt