SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Fri Mar 28 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MIDWEST INTO NEBRASKA...AND ACROSS THE WESTERN GULF COAST STATES... ...SUMMARY... A low-probability tornado and wind threat is forecast through this evening across portions of the western Gulf Coast States. Isolated severe hail is also possible from the Upper Midwest into Nebraska later this evening/night. ...Western Gulf Coast States... Southern-stream upper trough is currently located over northeast Mexico/far West TX. This feature is forecast to shift slowly east across south TX into the lower Sabine River Valley by the end of the period as modest mid-level flow translates across the northern Gulf Basin. Low-latitude nature of this feature should result in deeper convergence holding offshore much of the period. This is especially true given the multiple ongoing MCSs that are noted from the lower Rio Grande Valley into the northwestern Gulf Basin. Substantial convective overturning has occurred inland and air mass recovery will be limited across much of the TX Coastal Plain. Even so, adequate buoyancy will likely exist across far southeast TX into southern LA such that a few robust storms could emerge within the larger complex of convection. Forecast soundings suggest a brief tornado or wind gust will be the primary risks, and this appears to be a low probability threat. ...Upper Midwest into Nebraska... Northern Plains upper ridge is forecast to flatten a bit today as heights fall across the Dakotas ahead of a weak short-wave trough. Latest water-vapor imagery suggests one notable short wave is located over eastern MT. This feature will advance east today and sustain a broad swatch of low-level warm advection along a corridor from MN into northern lower MI. In the wake of the disturbance, surface pressures will build over SK/MB into the Dakotas and force a cold front to a position from southwest MN-central NE by 29/00z. While warm advection will be responsible for multiple bouts of elevated convection, any surface-based thunderstorm development should be noted along/ahead of the cold front as boundary-layer temperatures will warm rapidly and 0-3km lapse rates will steepen. Forecast soundings suggest convective temperatures will be breached by late afternoon along the wind shift over NE and high-based convection should develop. Gusty winds and hail are the primary concerns with this isolated activity. ..Darrow/Weinman.. 03/28/2025