The Monday afternoon edition of the ABC 33/40 Weather Xtreme video is available in the player below, and on iTunes:
To me, the easiest part of this forecast in recent weeks has been pattern recognition, and the ability to make broad statements like:
*Much of the nation will be flooded with very cold air in the next two weeks (in some cases, the coldest air in one or two decades)
*The southern U.S. will be dealing with winter storm threats on the southern periphery of the cold air
This is all working out nicely. Now, the hard part is dealing with the details of the winter storm threats. Lets dive into it….
TONIGHT/TOMORROW: Clouds from the ole STJ (sub-tropical jet stream) will increase tonight and tomorrow as another shot of very cold air approaches. We don’t expect any significant precipitation. You will really feel the new surge of cold air tomorrow night; by early Wednesday we will be down in the 20-24 degree range, with teens for the colder valleys across North Alabama.
WEDNESDAY-THURSDAY: Clouds will thicken during the day Wednesday, and a developing storm in the Gulf of Mexico will bring a variety of precipitation to the Deep South Wednesday night and Thursday. Not much change in thinking since the morning package… here are the details:
*Parts of North Alabama will have a risk of freezing rain (maybe even some snow flakes mixed in) from about midnight Wednesday night through 8:00 a.m. Thursday. At this point, the best chance of freezing rain (rain that falls when the surface temperature is 32 degrees or below) seems to be along and north of U.S. 278, or north of a line from Hamilton, Cullman, and Gadsden. This could lead to significant travel problems.
*Most of the snow from this system will come Wednesday night and Thursday morning along and north of U.S. 72, especially north of the Tennessee border. The I-40 corridor could see several inches of snow, including Memphis, Nashville, Knoxville, and Asheville.
*The I-20 corridor should get away with only a cold rain, but it is a very close call. I expect temperatures to be somewhere between 32 and 34 in the Birmingham area at 6:00 a.m,. Thursday. But, evaporative cooling will be an issue that the models don’t handle well; and with surface dewpoints below 10 degrees that is a concern. I sure cannot rule out icing problems as far south as Birmingham, but, hopefully there will be enough warm air advection to offset that cooling and we will get away with a cold, rainy morning along I-20. Everyone along I-20 needs to get up early Thursday to check on potential ice problems. Again, some icing in the Birmingham metro is a very real possibility early Thursday.
*South Alabama could even see some thunderstorms involved on Thursday as the WAA process will be more pronounced down there.
As always, this could, and probably will change during the next 24 to 36 hours… stay tuned.
FRIDAY/SATURDAY: The coldest air so far this season should roll in here as the weekend begins. The GFS MOS has a high of 42 here (Birmingham) on Saturday; I say it is 10 degrees too warm. A high of 32 is more like it considering the air coming our way. And, by Sunday morning, a low of 10 to 15 is a very real possibility.
LONG RANGE: Don’t want to go there… been spending all the time focusing on the mid-week event. Lets take them one storm at a time.
I will have the next Weather Xtreme video ready by 7:00 a.m. tomorrow… and we will be recording a new WeatherBrains podcast tonight, which we will post late tonight or early tomorrow. It never stops around here!