Twin States Weather Blog

Wild Weekend Ahead....

* This weekend's forecast is a very complex and difficult scenario. So, keep in mind that changes to this forecast are quite likely as we go through the next day or two. But, here's our latest detailed discussion about the unfolding winter weather setup for parts of the Southeast...

* An Arctic front is quickly advancing southward through the Southeast. The freezing line now runs from roughly Bowling Green, KY to Jackson, TN to just north of Little Rock, AR. This will continue southward through the day, although its progress will slow a bit because of the daytime heating. There are a few showers along the front, with a more concentrated area of rain falling behind the front.

* The temperatures behind the front are running a bit colder than our models were suggesting. Here are a few cities' actual temperature with comparisons to what our model guidance was predicting:

Little Rock, AR 6 AM
Observed: 34
NAM-MOS: 41
GFS-MOS: 40
NGM-MOS: 40

Memphis, TN 6 AM
Observed: 33
NAM-MOS: 42
GFS-MOS: 35
NGM-MOS: 42

* This only builds confidence that parts of the Southeast will see a significant ice event out of this. The big questions are where, and how much? We'll take it state by state...

MISSISSIPPI: As of right now, we believe the worst icing will come roughly between Interstate 40 and U.S. 82 in Mississippi. This includes Southaven, Tunica, Tupelo, Greenville, Greenwood, Winona, Starkville, Columbus, and West Point. A Winter Storm Watch has been posted for all of this area. Ice accumulations up to one-half inch are not out of the question, and significant travel problems are almost a certainty. Power outages could also become a problem, mainly in areas that see more freezing rain (as opposed to sleet and snow). The freezing line may come as far south as Interstate 20 early Sunday morning, but the precipitation falling at that time (if any) will be very light. But, we will continue to include a chance of light freezing drizzle along and north of I-20. No travel problems are expected for places like Meridian, Philadelphia, Quitman, Jackson, Newton and Hattiesburg.

TENNESSEE: Major icing could occur roughly along and south of Interstate 40. North of I-40, the precipitation will fall mostly in the form of sleet and snow, and accumulations there should be light (1-3"). Ice accumulations south of the Interstate, including the Memphis metro, will likely be between 0.20-0.40". This will be enough to create very hazardous driving conditions.

ALABAMA: Significant ice accumulations are possible across roughly the northern third of Alabama, where ice accumulations of up to a quarter inch are possible. Travel problems, especially on bridges and overpasses, are likely to develop. This includes cities such as Florence, Muscle Shoals, Cullman, Decatur, Huntsville, Athens, Gadsden and Fort Payne. Like the situation in Mississippi, the freezing line may dart down to the I-20 corridor briefly Sunday morning. This could cause some light freezing rain as far south as Eutaw, Livingston, Birmingham, Tuscaloosa, and Anniston. No significant travel troubles are expected along the I-20 corridor.

* Now that we've discussed WHERE, we need to discuss the timing of the developing weather...

TODAY: Showers will continue at times along the front, and a mass of rain moving across northern parts of Alabama and Mississippi will continue moving east. More showers may develop today, and intermittent rain is possible.

TONIGHT: The showers will continue across central Alabama and central Mississippi, including our area. Farther north, temperatures will fall below freezing, changing the rain over to a mixture of freezing rain and sleet for places like Memphis, Southaven, and Tunica.

SATURDAY: Ice will continue for northwest Mississippi, Arkansas, and much of western and central Tennessee. Here, intermittent periods of rain will continue. It will be cold here, with highs only the in the 40's.

SATURDAY NIGHT: The freezing rain situation will become critical across parts of northern Mississippi, northern Alabama and Tennessee. This is when we expect the worst of the weather for those areas. The freezing line will drop southward through the night, and light freezing drizzle is possible as far south as I-20.

SUNDAY: Light rain will continue at times here, as temperatures warm into the 40's. Freezing rain and sleet will still be a problem for north Mississippi, north Alabama and Tennessee. Snow will also continue across central Tennessee.

* Rain will continue Sunday night, lasting through much of the work week. The Arctic boundary will stall, serving as a focus for waves of weak upper troughs to move overhead. These upper troughs will kick off periods of rain, but they are very difficult to time. So, we'll leave a chance of rain in for Monday, Tuesday and Wednesday. But, keep in mind it will not rain that entire time.

* A few notes...The nature of the rain this weekend will not be a steady, soaking rain for the entire weekend. We will see periods of rain (and ice in the areas outlined above), then periods of dry and cold weather. Our graphic areas under this post remain mostly unchanged. However, this post is the latest info - use it for planning purposes.

* Check out these websites for the latest NWS winter weather products:

Mississippi Winter Storm Products
Alabama Winter Storm Products
Tennessee Winter Storm Products

posted by WTOK Weather Staff @ 7:06 AM