An early week cold front will trigger thunderstorms across the Southern U.S. Sunday and Monday. This has been something we’ve had our eye on for a little while. As an upper level disturbance lifts northeast from Southern California through the Southern Plains and into the Midwest, a surface low and trailing cold front will trigger showers and storms. On Sunday, the Storm Prediction Center has outlined part of the Southern Plains for the potential for some severe storms, with the main threat being strong straight line winds. The highest risk will be in Northeast Texas and Southeast Oklahoma near the Red River.
At first glance, this system meets some of the criteria we would look for in a potential winter weather setup here. Lapse rates (vertical temperature change), wind profiles, surface temperature and moisture, and a strong low level jet all would support the potential for stronger storms here as well. However, we have some additional limiting factors here that look to prevent our weather from being quite as volatile as Texas and Oklahoma’s.
First, while we do expect to have surface temperatures and moisture high enough to be marginally supportive of stronger storms, overall the air won’t be quite as unstable as it will be to our west.
In addition to less potential energy for storms to tap into, there will also be a spot in the mid levels of the atmosphere where the dewpoints drop and temperatures rise a bit with height.
This increase in temperature with height (a temperature inversion) is a layer of stability in the atmosphere, and is often called a “cap” because it can sort of act like a lid, keeping storms from boiling up.
In addition to a more marginal setup with respects to instability, the upper level muscle won’t be as defined either.
A fairly deep shortwave trough will provide plenty of upper level lift to help generate storms across Texas and Oklahoma, but by Sunday night, this feature is flattening out quite a bit. That means the best lift will be well North of the Tennessee Valley. Most of our “muscle” for storms will be associated with a weak cold front moving through. That can be enough for some storms, but without more robust upper level support, more significant or widespread severe weather appears unlikely.
There will still likely be a window Monday afternoon into Monday evening where a few storms could produce some gusty winds and heavy downpours, but widespread severe weather is unlikely.
If we do end up having a few storms that end up getting stronger, you can get alerts and forecast updates using Live Alert 19.