SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Wed Mar 16 2022 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN SC...COASTAL GA AND THE CENTRAL/NORTHEAST FL PENINSULA... ...SUMMARY... Isolated severe thunderstorms will be possible through this evening across parts of the Southeast. Large hail should be the main threat, with marginal potential for damaging gusts or a tornado. ...20z Update -- AL/GA/FL... The Marginal and Slight risk areas have been trimmed across parts of southeast AL, southern GA and FL with the 20z update. A dry slot noted in water vapor imagery will continue to suppress convection across much of northern FL into southern GA this afternoon/evening. Additional trimming of the Marginal risk across AL is based on observed ongoing convection and the position of the eastward-developing surface low. Across the central FL Peninsula, the severe probabilities have been shifted eastward as midlevel subsidence impinges on the region and the axis of greater instability pushes east toward the east coast. The 19z RAOB from MFL indicates modest effective shear with steep lapse rates and large SBCAPE. Vertical shear is likely a bit stronger to the north and large hail still appears possible with convection over the next few hours. Additional thunderstorm development also is expected across SC into the evening, and a continued hail/wind threat is expected for several more hours. ..Leitman.. 03/16/2022 .PREV DISCUSSION... /ISSUED 1127 AM CDT Wed Mar 16 2022/ ...Southeast U.S.... Upper-level low over MS/AL border region at 16z is forecast to lift northeast to vicinity of Charlotte NC by 12z Thursday. A surface cold front will move steadily east across eastern GA, SC and the FL Peninsula. Clearing in the wake of overnight storms across the central FL Peninsula will promote sufficient heating for development of MLCAPE ranging from 1500 to locally 2000 J/kg this afternoon. Shear profiles will be supportive of supercell structures with storms developing in advance of the cold front, with a risk for severe hail, perhaps significant if storms can maintain a more discrete spacing, and isolated damaging winds. Farther north across eastern GA/southern SC, abundant cloud cover persists although some breaks in cloud cover have developed based in latest visible imagery. A gradual increase in storm coverage is anticipated in this area over the next few hours in the vicinity of a NW-SE oriented baroclinic zone as large-scale ascent increases over the area. Wind profiles will be supportive of organized storms including supercells, with hail and isolated strong gusts possible. Curved hodographs in the lowest 0-2 km in RAP-based forecast soundings this afternoon would support at least some risk for a tornado or two over far eastern GA/southern SC, especially for any persistent/semi-discrete storm. Farther west across eastern AL/much of GA. isolated strong/severe storms will be possible near the upper low, where MLCAPE of 500-750 J/kg and cool mid-level thermal profiles will support a risk for mainly hail.
