Here Comes The Cold Air

The Monday morning map discussion video is on the server:

http://beta.abc3340.com/weather/video.hrb

In our forecast package last week today's forecast was for rain ending along with temperatures falling into the 30s. Quite frankly, that still looks good to me. Rain will slowly move off the the east today as the mercury drops. As of this writing, Birmingham reports 42, while Muscle Shoals and Huntsville are at 36. Look for the cold air to filter in here through the day, and most spots should be in the 30s this afternoon. What a miserable day.

A nice strip of heavy snow will develop today from the northeast corner of Tennessee through Virginia, and on up to Washington, Baltimore, Philadelphia, New York City, and Boston. Amounts of 2 to 4 inches are likely in this area, but spots will see 6 to 12 inches. If you are traveling up there, beware!

We will be dry and cold tomorrow and during the day Wednesday. MOS products stink; they are having a hard time handling the shallow cold air. I will use 22 for tomorrow morning, with highs only in the low 40s tomorrow and mid 40s on Wednesday. Those high temperature values might be too warm.

WEDNESDAY NIGHT/THURSDAY: Our forecast dilemma continues. I think there is now no doubt a storm forms in the Gulf of Mexico; the question is what will fall here? As we think this through, we have to remember this is early December, and major winter storms are very rare this time of the year. But, we cannot ignore the strength of the cold air. Lets look at some temperatures at 5:00 a.m.:

Siloam Springs, Arkansas 16
Kirksville, Missouri 8
Brookings, South Dakota -8
Mobridge, South Dakota -17

This is not your typical early December airmass... and you can't ignore those numbers. The cold air will be pretty shallow here... and probably only a few thousand feet thick by Wednesday night and Thursday.

So, what to do? Here is our initial thinking:

*Precipitation begins to overspread the state late Wednesday night, and continue into Thursday. For the I-20 corridor (Birmingham, Tuscaloosa, Anniston) I think the best course for now is to maninly mention a cold rain, possibly mixed with sleet. There is a chance, however, due to evaporational cooling there might be a period of freezing rain with temperatures down in the low 30s late Wednesday night/early Thursday. A little bridge icing is certainly not out of the question.

*A wintry mix is likely along and north of U.S. 278, or north of a line from Hamilton to Cullman to Gadsden. There seems to be a better chance of freezing rain late Wednesday night and early Thursday morning in this part of the state, and accordingly a better chance of bridge icing and some travel problems. I think there is also a chance the precipition could change to snow, probably a brief window, at some point late Thursday or Thursday evening as cold air is pulled in behind the developing low, which should be east of Alabama at that point.

Needless to say, all of this could change. Nailing down the details of an event like this is very hard to do several days in advance.

Friday through the coming weekend should be dry with moderating temperatures.

LONG RANGE: I don't trust the GFS in the short term, and I sure don't trust it in the long term. So... not much confidence here. But, I do think there are signs the cold air builds again and comes at us at times over the latter half of the month. I will write more about this on the afternoon post here and discuss on the afternoon map discussion video.

THIS WEEKEND: Sure seemed like a blur... very busy, as most people are this time of the year. I did enjoy seeing the big crowd down in Clay county at Wellborn Cabinet for their Christmas banquet. It was fun driving through Ashland; everyone was having a big party in the town square following Clay County's victory in the state title game at Legion Field.

TODAY: Will be headed to Vincent Elementary today to see the kids... but I will be back in the office for the next map discussion video which will be posted by 3:30. Have a great day and stay warm!