SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0149 PM CST Sun Nov 09 2025 Valid 092000Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO NORTHERN FLORIDA INTO SOUTHEAST GEORGIA AND PARTS OF THE CAROLINA COAST... ...SUMMARY... Isolated severe thunderstorms are possible through early evening from Florida northeastward into the coastal Carolinas. ...20z Update... The primary forecast change was a removal of hail/wind risk probabilities across portions of eastern NC. Multiple HRRR/RRFS/MPAS runs have shown a consistent signal for the possibility of strong updrafts/UH across northern FL, southern GA, and southeastern SC associated with the intensifying convection over the FL Panhandle/southwest GA. This aligns with recent observations/analyses that depict the best thermodynamic and kinematic environment roughly along the GA/FL line. Recent KTLH imagery suggests that some of this convection is already becoming undercut by the advancing cold front, so while embedded supercells will remain possible in the near term, the trend should be towards more clustered/linear storm modes through the evening with an attendant risk for isolated hail/wind. Further north across NC/VA, more aggressive CAM solutions hint that a robust storm or two may develop through early evening, but recent ACARS soundings sampled very weak low to mid-level lapse rates that should modulate updraft intensities despite a favorable wind profile. This, combined with a lackluster signal in guidance, limits confidence in the overall severe threat. ..Moore.. 11/09/2025 .PREV DISCUSSION... /ISSUED 1015 AM CST Sun Nov 09 2025/ ...FL into the coastal Carolinas... Water-vapor imagery this morning indicates significant amplification of the large-scale eastern U.S. trough is occurring, and is due primarily to a mid-level wave over the Mid South and an upstream disturbance over the Upper Great Lakes. A cyclone over the upper OH Valley will migrate east towards Long Island during the period as an attendant cold front sweeps east/southeast across the Southeast and Gulf of America. The airmass ahead of the front over the Carolina coastal plain into FL will gradually warm/destabilize and yield upwards of 1000-1500 J/kg of MLCAPE. Forecast soundings show effective shear magnitudes supporting organized storms. However, tempered lapse rates (900-600 mb layer) in combination with front-parallel orientation of the deep-layer shear and limited forcing for ascent ahead of the cold front, will act to partially suppress greater storm coverage and the overall severe risk given the magnitude of CAPE/shear. Nonetheless, isolated to scattered thunderstorms are forecast along and ahead of the front (perhaps into one or two small clusters over the FL Peninsula into southern GA) as it progresses across the region. A few damaging gusts are possible, particularly with any bowing structures that stay ahead of the front. Isolated hail is possible as well, primarily in the FL/GA border vicinity where buoyancy is greatest.
