The threat for tornadoes is particularly high, and with this two prong event, there would also be widespread wind damage from straight-line winds as well.
The threat will begin this afternoon and continue through the overnight hours.
Please read this carefully, and please pass the word around to friends, neighbors and family so that they get the word, too.
THE SET-UP: A powerful area of low pressure is developing over southeast Texas. This low will strengthen as it moves northeast to Monroe, LA. this afternoon and northward to the Tennessee valley tonight. Warm moist unstable air will spread northward from the Gulf.
POWERFUL INGREDIENTS: Strong wind fields from the surface to the upper levels will veer with height causing the sheer needed for tornadoes. The second ingredient is instability. While this parameter will not be off the scales, it will be high enough, based on the other strong factors for a dangerous severe weather outbreak across the South.
The Storm Prediction Center has a RARE Moderate risk for severe weather. I've never seen something like that on Christmas Day.
TWO PRONG THREAT: The first threat will begin this afternoon. Warm moist air will be the breeding ground for supercell thunderstorms to develop. These storms will tend to rotate, and some will produce tornadoes. Given the strong parameters, a few long-track strong tornadoes are possible. We think the greatest threat of strong tornadoes will be primarily west of I-65 and south of I-20. Then, as a strong squall line moves into the state tonight and marches eastward through the overnight hours, the threat will shift to more of a damaging wind threat. The threat of damaging winds with the squall line is very high. Also, a few spin-up tornadoes are possible with the line itself.
The Storm Prediction Center tornado threat today, in the hatched area is very strong indeed.
Wind damage risk extremely high.
TIME LINE: The threat for isolated tornadoes will begin early this afternoon in the west and southwest counties and continue into the overnight hours, followed by the squall line. We think the best time line for severe weather is between 2:00 PM in the west and about 3:00 am in the East. That's a pretty long window. Please stay weather aware!
FINALLY: WSFA 12 News will be fully staffed and will bring you watches and warnings as they occur. We will be with you on air, online, on your mobile devicesand through social media.
SPREAD THE WORD: Help us get the word out about today's Christmas Day severe weather threat. Tell neighbors and friends to be aware and be ready. Have a plan of action. Discuss in advance where is the best safe place for your family to go if a tornado warning is issued for your area.
DO NOT rely on hearing sirens as your means of getting a warning! These are meant for people who happen to be outside, and are NOT meant to be your primary source of hearing a warning. Make sure your NOAA Weather Radio is on and in the alert mode.
We will get through this together, and you can help us by tweeting your severe weather reports and posting to Facebook.
Try to enjoy your Christmas Day. We will be with you, of course.
The WSFA 12 Storm Vision team is in the weather center and will keep you notified of changes.