
SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Thu Mar 13 2025 Valid 131630Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF ALABAMA INTO SOUTHWEST GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing hail and locally damaging gusts are possible from parts of Alabama into southwest Georgia and the Florida Panhandle this afternoon and early evening. ...Southeast... A mid-level vorticity maximum over the Mid-South late this morning will become less well defined as it moves slowly eastward across the TN Valley and Southeast through the period. Stronger mid-level flow is expected to remain over southern/coastal portions of the Southeast today. But, cold mid-level temperatures (around -18 to -21 C at 500 mb per 12Z regional soundings) in conjunction with filtered daytime heating and modest low-level moistening will support weak destabilization from parts of AL into southwest GA, and the FL Panhandle. Current expectations are for isolated to scattered thunderstorms to develop across these areas through the afternoon, as modest ascent with the weakening mid-level trough moves through. Most guidance suggests that greater convective coverage may occur over parts of southeast AL into southwest GA and perhaps the FL Panhandle, in closer proximity to greater low-level moisture and the mid-level jet. With modest to sufficient deep-layer shear, clusters to marginal supercell structures could pose an isolated threat for both severe hail and damaging winds this afternoon through early evening. See Mesoscale Discussion 167 for additional details on convective development and evolution through 20Z. ...Southern Arizona... A cold front will move eastward across southern AZ today, as an upper trough progresses over the Southwest. Showers and thunderstorms are expected to spread across this region in tandem with the front. Winds aloft will be quite strong, as an 80-100 kt mid/upper-level jet max digs southward along/near the international border. Some higher momentum flow may mix to the surface, and a gust could approach severe limits within low-topped convection. However, the weak thermodynamic profile would suggest the severe threat will remain low. ..Gleason/Wendt.. 03/13/2025