New Tornado Watch Issued to the West, Timing Update

The anticipated tornado watch has been issued for parts of eastern Arkansas, western Tennessee, northeastern Louisiana and northern Mississippi. It comes right up to the Northwest Corner of Alabama.

It is interesting to note that it is a PDS (Particularly Dangerous Situation) watch.

Click image to enlarge.

The timing on the event has come into a little clearer focus. As I alluded to earlier, the first disturbance is passing off to the northeast, taking the first round of showers and storms with it.

Clearing is already working into west Alabama in the sinking air behind the disturbance. This sinking air will help create a cap on the atmosphere this atmosphere and limit storm development while allowing instabilities to really rise over West Central Alabama. They may reach over 2,000 j/kg over places like Sumter, Greene, Hale, Perry and Marengo Counties, with moderate instability over much of the western half of Central Alabama as far north as Walker, Jefferson and Shelby Counties.

Any storms that develop this afternoon have the potential to become severe with that instability, but the good news is that wind shear will probably be relaxing temporarily, limiting the severe potential. The threat through the afternoon should be isolated.

Storms will become severe to our west this afternoon. There is a high probability of strong tornadoes in that tornado watch to our west. Two things will happen tonight.

Instability will lessen after temperatures decrease after sunset, but there will still be over 1,000 j/kg of CAPE over much of Central Alabama. This is plenty sufficient for severe weather. As the trough approaches from the west, winds in the atmosphere will increase and accordingly so will wind shear. Any storms that form ahead of the main line tonight will have the potential to become severe with damaging winds and even a tornado or two.

Then the big line of storms will reach Northwest Alabama around 7 p.m. and will push eastward across the state during the night. It may not get much to the southeast of I-59 before it stalls and fizzles. But it will produce severe weather tonight, including damaging winds and possible tornadoes, especially in the moderate risk area over the Northwest Corner of the state at the Enhanced Risk area which is just northwest of I-59. All of ALabama is in the SPC standard “slight” risk category which indicates a chance of severe weather for today and tonight.

And a heads up that we could deal with a another threat tomorrow night. It is never good to have severe weather on Christmas Eve.

Stay weather aware through the day and night.

Category: Alabama's Weather, Severe Weather