Sunday, December 15, 2019 3:03 PM

Tornadoes, damaging winds and large hail possible Monday across the South

Christopher Nunley

Severe thunderstorms are likely for parts of the South Monday into early Tuesday. A potent shortwave will cross the Rockies late today and move into the Plains overnight Sunday. In response to this shortwave approaching the region from the west, warm & moist air will stream into the South Sunday night into Monday, helping set the stage for severe thunderstorms. As the shortwave treks east on Monday, it will send a cold front into the region. This cold front will provide the lift needed for severe storms to quickly develop.

The best chance for severe storms will be late in the day Monday. Initially, Monday morning, a few rain showers & drizzle possible across Louisiana, Mississippi & Alabama. A few non-severe storms will begin to develop along the cold front around 8:00 am across western Tennessee, northwestern Mississippi & northern Louisiana. Those storms will slowly intensify as the cold front moves southeast. By noon, a broken line of storms will exist along the cold front extending from central Tennessee toward the southwest extending into far southeastern Texas. The line of storms will begin to fill-in and intensify as the airmass destabilizes during the afternoon hours. A few storms may try to develop ahead of this main line across eastern Louisiana, Mississippi & western Alabama. These storms will have a favorable environment to produce high-impact severe weather. Heading into the overnight hours of Monday, storms will shift east toward Georgia and begin to lose some of their punch. (Note: use the graphics below as a tool for a general idea of timing/placement of thunderstorms. Exact timing and location of storms Monday will vary.)

The atmosphere will be primed for severe storms Monday afternoon & evening. There will be adequate shear and steep lapse rates. While morning cloud cover is expected across most of the South, as moist air feeds in from the South, a few breaks in the clouds can be expected by the early afternoon hours. This will allow for instability to increase throughout the day. These parameters will allow storms to produce all modes of severe weather; tornadoes, damaging winds and large hail are all possible. 

The best areas to see severe storms is across Louisiana, southeastern Arkansas, Mississippi and Alabama. But, the severe threat extends into eastern Texas, southern & central Tennessee, western Georgia and the Florida Panhandle. There is an enhanced risk of severe storms from central Louisiana east into west-central Alabama. This is where the best coverage of severe storms is expected and where the best chance for tornadoes will exist. 

The severe threat will continue beyond the daylight hours. Nighttime severe weather is particularly dangerous across the South. Make sure you have a plan in place in case a warning is issued for your area, and make sure you have reliable & accurate resources to receive all watch/warning information.