SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1139 PM CST Fri Feb 14 2025 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY...MID-SOUTH...AND CENTRAL GULF STATES... ...SUMMARY... Severe weather is expected from East Texas and Mid-South into much of the Southeast. Scattered to numerous damaging wind gusts and a few tornadoes are the primary threats. Storms are expected from late afternoon through the overnight hours. ...Discussion... Strong 500mb jet is currently digging southeast across the lower CO River Valley. This feature is forecast to translate into far West TX early in the period, then increase in intensity as it ejects into the downstream side of the upper trough during the overnight hours. Strong 12hr mid-level height falls are forecast to overspread much of the lower MS/TN Valley region, with upwards of 210m expected across northern areas by the end of the period. This evolution will induce a surface low across north-central TX early which will track into eastern AR by late afternoon, then deepen as it lifts into the OH during the overnight hours. LLJ should respond markedly and focus across the lower MS Valley during the first half of the period. Boundary-layer air mass is currently cool/stable across this region with modified Gulf air just now approaching the upper TX coast and southern LA. Until this air can advance inland any thunderstorm activity should be elevated in nature, and likely sub-severe. Latest thinking is boundary-layer recovery will occur across east TX into southern AR by late morning, then further destabilization should contribute to surface-based buoyancy that will support potentially robust thunderstorms ahead of the aforementioned surface low/cold front. Forecast soundings exhibit very strong shear across this region with 0-3km SRH on the order of 500 m2/s2. Supercells are expected to develop along a corridor from northern LA into western TN from the afternoon into the early evening. Damaging winds and tornadoes are expected. Additionally, given the strength of the wind fields, and very dynamic, fast-moving trough, there is a risk for strong tornadoes. Frontal convection should expand in areal coverage as the boundary surges southeast. During the latter part of the period, a secondary corridor of concentrated severe may evolve from southeast LA, across southern MS into southern AL. Strong LLJ will shift east overnight, and somewhat higher theta-e air mass should have advanced inland into this region ahead of the surging cold front. While damaging winds can be expected with the more linear convection, some risk for strong tornadoes does exist with more discrete supercells. ..Darrow/Thornton.. 02/15/2025
