A significant all-hazards severe weather episode is likely to occur across much of the Central and South Central United States starting Friday and continuing into this weekend. In some spots, significant winds (70+ mph), large hail (2+ in), and strong to violent tornadoes (EF2+) will be possible. It is imperative that you remain alert for potential watches and/or warnings if you are in the affected areas.
Friday (3/14)
Synopsis: A system will rapidly deepen and overspread across the Ozarks and MS Valley into Friday. An impressive area of near 60-degree dewpoints and impressive southwesterly flow across the region will develop. The combination of the above and modest MLCAPE will set the stage for significant areas of wind gusts, as well as supercellular development farther south into the outlook area. Recent high resolution guidance supports the potential for two sections of the event, each producing its own main risk of hazards.
The risk for Friday can be split into two different zones, and while the current outlook remains a wind-driven moderate risk (45% hatched), there remains a fairly impressive 10% hatched risk for tornadoes across much of Illinois all the way into Mississippi. In the northern area, primarily across the St. Louis metropolitan area, and points around it, significant swaths of wind gusts (some exceeding 70 mph) will remain possible, along with the possibility of large hail. The recent HRRR runs (pictured below) continue to support a bowing segment of linear mode thunderstorms, which commonly produce areas of significant damaging winds.
It’s important to note that while the northern mode will remain mostly linear in mode, there remains the potential for supercells, especially near/south of this line. This would keep a tornadic potential at play for much of the area, and a tornado risk will increase with southern extent.
Further south, significant supercell development is likely into Alabama/Tennessee, and while this is mostly occurring overnight, this is expected to remain a mostly favorable environment for significant severe potential. It’s important to note that forcing may hinder severe thunderstorm development across the southern portions of the outlook area, however any storm that is able to develop will quickly pose a significant risk for tornadoes, hail, and damaging winds.
Saturday (3/15)
Synopsis: The focus for Saturday turns towards the Deep South, into much of Alabama, where a significant portion of the area may be at play for significant and violent tornadoes into the night on Saturday. A significant area of mid/upper flow will overspread the region into the forecast area, and will be coupled with quite an intense area of 500mb jet streak. Coupling this with classic Gulf dewpoints into the mid/upper 60s will set the stage to support a significant and widespread risk for severe thunderstorms across much of the Southeast US into early Sunday (3/16).
While a majority of CAMs still remain slightly outside the timeframe for analysis, the setup is clear showing an impressive severe weather setup across much of the region. This is especially true across much of the Deep South, where MLCAPE values approach 2000 J/kg in some spots, and while this number does decrease the further north you go, it’s important to note that this setup remains favorable for intense supercells across the region. The most likely location for tornadic potential remains across much of Mississippi and Alabama.
Further north, into Ohio, a slight risk remains in effect; however, due to precipitation early in the day, there could be some uncertainty into how much clearing (destabilization) occurs in the area. If enough clearing occurs, the main risk in this region would likely remain damaging wind gusts in this area.
Other
The last Day 2 high risks issued happened twice in history, April 14th, 2012 and April 7th, 2006. We cannot rule out issuance of a high risk for day 2, however, regardless of level, the severe weather risk on Saturday must be taken extremely seriously.
It is important to monitor and prepare for significant severe weather if you are in or around these higher-end risks, and be prepared to seek shelter in a tornado shelter or basement if a warning is issued for your area. Always have multiple methods of monitoring and receiving severe weather alerts, including phone apps, wireless emergency alerts, weather radio or AM/FM stations, and local TV stations. Those inside should never rely on tornado sirens to be alerted to seek shelter.
Prepare a severe weather kit, including helmets! You can find more information about tornado preparations here.
Special Coverage Mode has been activated for this event! Live coverage mode will be available for this event, if necessary.
Our Central Alert Repository is prepared for the influx of severe alerts expected tomorrow. You may also listen to GWES ERN Stations for the relay of these alerts.
Interested in joining GWES? We will be providing coverage and updates on this system throughout the event on our Discord at https://discord.gg/GWES.
Contributions to this forecast were made by the following GWES Forecasting members: Jon, kurt, KRZY, wxtership
