
SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Sun Mar 16 2025 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER OHIO VALLEY TO THE CENTRAL FLORIDA PENINSULA... ...SUMMARY... Sporadic damaging wind swaths and a few tornadoes will be the primary threats this morning through dusk across a broad portion of the East. ...OH Valley/northern Middle Atlantic... Seasonally strong upper trough, though bimodal in nature, will shift into the OH Valley/Southeast by the end of the period. Ahead of the main trough, a lead mid-level speed max will translate across eastern OH/western PA with 500mb speeds in excess of 120kt. This feature will be partly responsible for sustaining a surface low that should track from southeast lower MI into ON by early afternoon. Additionally, LLJ is forecast to increase markedly across western PA early in the period, and this will aid moistening ahead of the short wave. Early this morning, an elongated corridor of convection/precipitation extends from the FL Panhandle, northeast into OH. Warm advection will likely maintain this activity which will be ongoing at the start of the period. Latest model guidance suggests a secondary band of convection will develop along/ahead of the front by mid-late morning, and an upward evolving, strongly forced line of storms, and a few embedded supercells, will surge east into western PA. Damaging winds seem plausible with this convection, and profiles also favor some risk for a few brief tornadoes. ...Southeast... Mid-level heights will fall across the southeastern U.S. early in the period as low-latitude jet core shifts east along the Gulf Coast into GA. This will ensure the primary synoptic front progresses steadily east through the period. By 18z the wind shift should extend from the southern Appalachians into the eastern FL Panhandle. Subsequent movement will result in the front advancing into the southern FL Peninsula by 17/12z. Scattered strong/severe convection, with some risk for supercells, will be noted ahead of the surging boundary. Forecast soundings exhibit very strong 0-6km bulk shear, and ample ESRH will be more than adequate for a risk of a few tornadoes. Steep mid-level lapse rates also suggest the more robust updrafts should generate hail. Overall, severe threat will shift east/southeast through the period. ..Darrow/Moore.. 03/16/2025