SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Sat Apr 05 2025 Valid 051200Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER SABINE RIVER VALLEY TO THE TENNESSEE VALLEY... ...SUMMARY... Severe storms, capable of producing damaging wind gusts, large hail and several tornadoes are expected from the Sabine River Valley northeastward into the lower to mid Mississippi and Ohio Valleys. Strong tornadoes, very large hail, and severe gusts will be possible in parts of the lower to mid Mississippi Valley. ...Sabine River Valley to Kentucky... Seasonally strong upper trough is digging southeast across the southwestern U.S./northern Mexico. This feature should shift east into the southern Plains during the latter half of the period as a 500mb speed max translates through the base of the trough into south-central TX by 06/00z, then into western AR by the end of the period. In response to this feature, a weak surface low is expected to develop in the lee of the higher terrain over the lower Rio Grande Valley, then track northeast along the boundary into the lower Sabine River Valley by late afternoon. High-PW air mass extends across the northwestern Gulf Basin, arcing northeast across the lower MS Valley into the TN Valley. Surface dew points are well into the lower 70s into western MS, and this will lead to a corridor of SBCAPE on the order of 3000 J/kg across this portion of the warm sector. Early this morning, an expansive corridor of convection extends along/north of the front from AR into western KY. This zone will gradually sag southeast through the period and will continue to serve as a focus for robust convection. Additionally, an expanding area of elevated convection is maturing ahead of the main short wave across west TX, and these storms will spread northeast with an attendant threat for hail into the early part of the period. Very strong shear is noted along/ahead of the frontal zone, and will continue to support organized, long-lived supercells. Current thinking is convection will be most concentrated along the warm front early, but diurnal heating will contribute to destabilization such that scattered-numerous storms should evolve along the cold front as it surges east across TX into LA, during the evening hours. Environmental parameters favor tornadic supercells, and strong tornadoes are certainly possible, in addition to large hail and wind. ..Darrow/Supinie.. 04/05/2025
