SPC Nov 28, 2020 0830 UTC Day 3 Severe Thunderstorm Outlook
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CST Sat Nov 28 2020 Valid 301200Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FLORIDA/COASTAL GEORGIA INTO THE CAROLINAS AND MID-ATLANTIC... ...SUMMARY... Isolated strong to severe thunderstorms capable of producing damaging winds and perhaps a couple of tornadoes appear possible on Monday from parts of Florida and coastal Georgia into the Carolinas and Mid-Atlantic. ...Florida/Coastal Georgia into the Carolinas and Mid-Atlantic... A large-scale upper trough should evolve into a closed low over the Midwest/OH Valley and central Appalachians on Monday. A mid-level vorticity maximum embedded within this upper trough is forecast to move quickly northeastward from the central Appalachians into the Mid-Atlantic through Monday afternoon. A deep surface low should likewise develop northeastward in tandem with this vorticity maximum. A cold front trailing from this surface low will likely sweep eastward across much of the FL Peninsula and the East Coast through the day. A warm front extending northeastward from the surface low will probably make some northward progress across parts of the Mid-Atlantic through Monday afternoon as well. A line of low-topped showers/storms along or just ahead of the cold front should be ongoing at the start of the period from near the surface low in WV/western VA southward to northern FL. Although instability may remain modest across most of the warm sector ahead of this line, generally low to mid 60s surface dewpoints should be enough to support weak surface-based instability through the day. A very strong (50-60+ kt) south-southwesterly low-level jet should be present over the central/eastern Carolinas and southern VA Monday morning, and this feature is forecast to shift northward across the Mid-Atlantic through the day. Given the strength of the low-level flow and sufficient, albeit weak, forecast instability, strong to damaging winds may occur with storms that either persist along the cold front or develop ahead of it over the open warm sector. A couple tornadoes also appear possible, mainly across parts of eastern SC/NC/VA to the Delmarva Peninsula and perhaps NJ in associated with the low-level jet and potentially greater low-level moisture and instability. Even so, there is too much uncertainty regarding sufficient destabilization to include higher severe probabilities for now. Farther south, low-level convergence along the cold front and deep-layer shear are both forecast to be somewhat weaker across coastal GA and the FL Peninsula. Still, there may be isolated strong/gusty winds with any storms through Monday afternoon. ..Gleason.. 11/28/2020
Read more
There’s more click here.