Today's Weather Discussion: Thanksgiving Day Mess
Wednesday, Nov. 24:
Lots to talk about over the next 24-36 hours, as we'll be seeing a wild swing in temperatures, lots of rain, and maybe even some wintry weather.....all just in time for our Thanksgiving Day plans.
The second of this week's three rounds of rain made for a soggy start to our morning, with rainfall totals ranging anywhere from 0.50" to over 1.50". Numbers in the 40's this morning are on a steady climb this afternoon, with a warm front lifting northward through the area. A drastic difference in temperatures behind the warm front, with numbers in the mid 70's as close as Memphis. As the front continues to lift north, temperatures here will rise into the mid 60's tonight, and remain steady through tomorrow morning. Lots of moisture will be surging into the region as well, leading to scattered shower and thunderstorm chances tonight. There could even be a couple of stronger storms tonight over parts of SE MO and S. IL, as shown by this afternoon's outlook from the Storm Prediction Center.
Looking ahead to our Thanksgiving Day....what a mess! Things will start out very mild, with mid 60's area-wide. A cold front will be just to our west by daybreak, with rain likely falling in SE MO & S. IL. This front will make steady eastward progress during the morning, making it roughly to the Ohio River by noon, as seen below:
The heaviest rain will fall just ahead of and behind the cold front....with the heaviest rains expected across SE MO & S. IL during the morning and midday hours, and across KY & TN during the afternoon. This could pose some problems with minor flooding. Our recent drought has resulted in rather hard soil conditions, and that will result in faster runoff with rainfall. That increased runoff, combined with leaf debris clogging up storm drains, will likely result in problems with poor drainage and standing water on roadways. The National Weather Service has issued a Flood Watch through tomorrow night. As you make travel plans for tomorrow, make sure to allow extra time to drive on wet roads and in reduced visibility, and remember to never drive over flooded roadways. On top of what we already received this morning, an additional 1-3" or more is expected through tomorrow night. Here's a look at the NWS/HPC rainfall map through Friday:
In addition to the heavy rain threat, the other big story is going to be a dramatic drop in temperatures. Temperatures will remain in the 60's over much of the area into the morning hours, but as the cold front sweeps through the area by late afternoon, the bottom will fall out of the thermometers. Numbers will tumble through the afternoon, and by sunset, much of the area will have fallen into the 30's. This fast invasion of cold air will likely occur before moisture exits to our east, which will likely result in a change over to some wintry precipitation. With temperatures falling steadily, I wouldn't be surprised to see all forms of precip....rain, freezing rain, sleet, and snow....at some point across the area. The window of opportunity for this wintry mix will be small, as moisture will depart quickly as the cold air arrives. With ground temperatures likely to still be well above freezing, we don't expect any accumulation or major travel impacts. However, keep in mind that bridges, overpasses, and other elevated surfaces can freeze at tempertures above 32, and there could be some patchy slick spots late tomorrow night.
From a wider perspective, the storm system that will bring a messy day to our area will also bring nasty weather to a large portion of the midwest. Travel will be a headache along interstates 24, 57, 55, 64, 70, & 65. Here's a look at the Weather Channel's Interstate Travel Forecasts for tomorrow and Friday:
Beyond tomorrow, things get much quieter, and colder, for the weekend. Shoppers will have to brave temperatures in the low to mid 20's early Friday morning, but all precip will have come to an end for those doorbuster sales. Sunshine will be back Friday, Saturday, and Sunday, with a slow warmup over the weekend. More rain is in the forecast for next Monday....we'll worry about that after tomorrow.