Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
451 ACUS48 KWNS 110904 SWOD48 SPC AC 110903 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0403 AM CDT Sat May 11 2024 Valid 141200Z - 191200Z ...DISCUSSION... A shortwave trough is expected to extend from the Mid MS Valley through the Lower MS Valley early D4/Tuesday before then gradually progressing eastward through the TN Valley and MS/AL throughout the day. This wave is then forecast to continue progressing eastward through GA, northern FL, and Mid-Atlantic on D5/Wednesday. Farther west, another southern-stream shortwave trough is expected to move across northern Mexico and into the southern Plains on D5/Wednesday, continuing eastward through the Lower MS Valley on D6/Thursday. Some severe potential may materialize across the Southeast and FL on D4/Tuesday, where moderate buoyancy and shear could be in place ahead of the approaching shortwave. However, there is some chance the better low-level moisture and buoyancy will remain displaced south of the better forcing as a result from either thunderstorm development along the coast late Monday night/early Tuesday morning or an overturning of the airmass by a convective line. This uncertainty limits predictability. Low-level moisture is forecast to advect back northward across the southern Plain on D5/Wednesday ahead of the southern-stream shortwave trough mentioned above. Thunderstorms are possible from the TX Panhandle into the Edwards Plateau as ascent attendant to this wave interacts with this moisture and buoyancy. However, vertical shear is currently expected to be fairly modest across much of the region, with the strongest shear expected farther south where convective evolution is less certain. Uncertainty regarding severe coverage is too high to highlight any areas with this outlook. Spread within the guidance increases after D5/Wednesday, with split flow contributing to low-predictability. Even so, the persistence of favorable low-level moisture and buoyancy from TX across the Southeast states suggest some severe potential could materialize from mid-week through the weekend. ..Mosier.. 05/11/2024