An interesting weather situation is plaing out tonight as a very powerful upper level system drops southeastward through Missouri. This upper low will swing eastward, pushing a cold front into Alabama tonight, accompanied by rain changing to snow overnight. There is good model agreement that much of the area will get at least 1 inch of snow overnight, with a good chance of 2-3 inches in many places and a few spots registering 4 inches or more.
Here are a few notes this evening…
EVAPORATIVE COOLING
As the rain begins, temperatures will drop due to the effects of evaporative cooling. The temperature dropped 4 degrees at Memphis in the hour after the rain started. This will help lower temperatures quickly.
RAPID TEMPERATURE DROP
The front has passed through Monticello, AR, in the southeast part of the state. There the temperature fell 12 degrees in two hours. Strong NW winds 18 gusting to 28 mph with temp/dewpoint 44F/40F and rain. Strong cold air advection will begin when the front arrives, dropping the temperature to near freezing within about 3 hours.
ARKANSAS REPORTS
Pine Bluff 34F Light Snow
Camden 34F Light Snow
Eldorado 36F Light Snow
Monticello 36F Rain
ARRIVAL IN ALABAMA
The front extends from Dyersburg TN to Memphis to Greenville MS at this hour. It should reach Hamilton around 10-11 p.m., Jasper 11 p.m. – midnight and Birmingham between 1 and 2 a.m.
RAIN FIRST, CHANGING TO SNOW
Rain will begin about the time the front arrives. Winds will shift to the northwest and gust to 25-30 mph. It will take about two hours for the rain to change to snow, then it will snow for a couple of hours. The atmosphere may be rather unstable with cold air aloft, and a few reports of thundersnow could be expected. Areas that see this convective activity could get a couple of inches of snow very quickly.
TRAVEL PROBLEMS
Travel problems will develop in areas where snow accumulates during the early morning hours. Temperatures will likely not get above freezing in the morning across Central Alabama with a biting northwest wind and occasional snow flurries.
WINTER WEATHER ADVISORIES
Winter weather advisories and winter storm warnings cover a wide area from western Pennsylvania to Central and Southern Mississippi.
BATON ROUGE
Expecting a wintry mix during the pre-dawn hours in Baton Rouge and parts of Lousiana. Winter weather advisories have been issued for Parishes around Baton Rouge.
STRONG STORM CROSSING MISS RIVER
The NWS in Jackson is tracking a strong storm capable of producing small hail about 23miles nortwest of Vicksburg. It will pass near Rolling Fork in the Delta in the next 90 minutes.
