Rain, Wind And Storms to Snow, Wind And Cold

■6:45am Radar

■SPC OUTLOOK

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SPC AC 050548 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1148 PM CST Tue Mar 04 2025 Valid 051200Z – 061200Z …THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN CAROLINAS INTO SOUTHEAST VIRGINIA… …SUMMARY… Severe thunderstorms capable of producing scattered damaging-wind gusts and a few tornadoes are possible Wednesday across parts of the eastern Carolinas into southeast Virginia. Other strong to severe storms may occur across parts of Florida and east Georgia, and also from the Allegheny Plateau into the Mid Atlantic. …Synopsis… An intense upper trough, initially over the MS Valley this morning, and characterized by a 500 mb jet streak of 90+ kt, will pivot east across the eastern U.S. through the period. Through the morning and early afternoon hours, a southerly low level jet greater than 60 kt will overspread the Southeast coastal vicinity into the Mid-Atlantic and lower Great Lakes regions. At the surface, strong warm advection will transport 60s F dewpoints northward ahead of an eastward-progressing cold front from FL into southeast GA and as far north as southeast VA. Moisture will become more modest with northward extent into eastern OH/PA/western NY. The net result will be a modestly unstable airmass in the presence of intense deep-layer flow supporting a large area of strong to severe/damaging wind potential. Tornado potential also is possible, with greater potential expected from the Carolinas into southeast VA where low-level moisture will be greater. …VA south to north FL… A QLCS is expected to be ongoing this morning, extending from western WV/VA and the western Carolinas into southeast GA and north FL. Diurnal heating will be limited, and low-level lapse rates will remain poor. This will pose some challenge for purely surface-based convection. Nevertheless, very strong large-scale ascent amid intense wind profiles will likely be sufficient for swaths of damaging gusts. Furthermore, forecast soundings indicate the presence of midlevel dry air just ahead of the eastward-advancing QLCS across the Carolinas and VA. This could further aid in some downward transport of stronger winds. Where 60s F dewpoints are achieved, QLCS tornadoes also will be possible, especially if backed low-level flow can be maintained to further enhance low-level SRH. While instability will likely be greater with southward extent, large-scale ascent will be lifting north of the GA/FL vicinity. Strong deep-layer flow will still be in place, and coupled with modest instability, this should result in some continued organized convection capable of strong to severe gusts. …Lower Great Lakes Vicinity… Further north, instability will be quite limited given a cooler boundary layer and dewpoints generally in the mid 40s to mid 50s F. However, cold temperatures aloft will result in steep midlevel lapse rates and foster MUCAPE values up to 500 J/kg. Additionally, closer to the surface low, vertically veering wind profiles with effective shear values near 40 kt, will support isolated low-topped supercells and perhaps linear segments. Strong to severe gusts, isolated hail and perhaps a tornado will be possible with this activity this afternoon. ..Leitman/Squitieri.. 03/05/2025