Rain showers have been attempting to work into the area from the west as an area of low pressure is developing along the Gulf Coast. A very powerful upper level low is fueling this surface low's development, and it will track to our south through the day on Tuesday. Rain will arrive this evening for all of us and last heavily through the first part of our Tuesday. By Tuesday morning, most of us could see 2-4 inches of rain with some spots picking up close to 5". Because of the heavy rainfall expected, a Flood Watch has been posted for most of East Mississippi.
The rain will taper off to just showers as we work into the afternoon and evening hours on Tuesday. As the upper level low swings through between about 9pm Tuesday and 2am Wednesday, cold enough air through our entire atmosphere may be present to produce some wintry precipitation (for more on that, read below, but it is quite technical).
The snow growth region (-10 to -18 Celsius) looks to have enough moisture between the times listed above for the upper level low to pass over to produce snow. The problem is not the production of snow, it is what happens as it falls to the ground. Models are indicating that temperatures for the first part of this time period may still be too warm for the snowflakes to make it to the ground completely frozen, so rain still looks likely. From about 11pm to 1am, enough cooling looks to have taken place that we could see wet snow make it to the ground or, in places with just a little warmer air aloft, sleet falling. The time frame for any winter weather looks short as the low will start ushering in drier air aloft and remove most of the moisture from the snow growth region, ending any chance at wintry precipitation.
If we do see snow or sleet, little to no accumulation is expected and it should not impact travel plans for Wednesday, as most of the day will also be above freezing, and with the large amount of rain expected, most of it will melt on contact. Wednesday looks to be the coldest day since March 2 when we hit 40 and January 16 when we hit 39 (which is the current forecast high for Wednesday).
We will remain dry through the rest of the week and weekend, but Thanksgiving and Black Friday will be on the chilly side. Rain returns on Monday with our next system.