1PM Day 1 Convective Outlook for Sunday, February 15. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEASTERN GEORGIA INTO NORTH AND WEST-CENTRAL FLORIDA
SUMMARY
Scattered severe thunderstorms remain possible this afternoon and evening across parts of southern Georgia into north and west-central Florida. Both damaging winds and a few tornadoes may occur.
20z Update
A line of thunderstorms continues eastward into the eastern FL Panhandle/northern FL Peninsula. Ahead of this line, dew points are in the mid to upper 50s. MLCAPE remains somewhat weak inland, though some slow increase is noted ahead of the line amid south-westerly warm air advection and filtered daytime heating. Regardless of weaker thermal profiles, strong upper level flow persists with deep layer shear for organization remaining strong across the eastern FL Panhandle into the northern FL Peninsula. The threat for strong convection with potential for damaging wind and a tornado will continue inland for the next few hours.
A Marginal Risk was maintained across portions of southern/central Georgia where some redevelopment of thunderstorms is noted over the last hour. The modestly unstable air mass ahead of this activity may support potential for isolated damaging gusts through the afternoon.
Southeast
A mature mid-level cyclone evident in water vapor and visible satellite imagery late this morning over MS/AL will continue to move quickly eastward across the central Gulf Coast States this afternoon, eventually reaching the Atlantic Coast later this evening. Latest surface analysis shows a weak low over northern MS and greater dewpoints present over the northeast Gulf, as strong low-level warm advection contributes to moisture transport ahead of an ongoing line of thunderstorms across the FL Panhandle and southwest GA.
This pre-frontal band of convection is gradually strengthening late this morning, even with modest mid-level lapse rates and saturated profiles through much of the troposphere limiting updraft strength. Boundary-layer instability will gradually increase downstream across north FL/southern GA this afternoon as filtered daytime heating and some increase in low-level moisture occurs (surface dewpoints rising through the upper 50s to low/mid 60s). Peak MLCAPE may reach values of 500-1000 J/kg per consensus of 12Z guidance.
With ample low-level and deep-layer shear associated with the mid-level cyclone present over the developing warm sector, organized convection mainly in the form of an eastward-moving QLCS is expected to persist through the afternoon/evening as this activity moves across north FL/southern GA. The northern extent of the severe risk into southern/central GA/SC remains uncertain due to weak instability forecast across these areas, but some guidance suggests additional strong convection may develop across these areas in closer proximity to cooler temperatures aloft with the upper trough.
Given the expected strength of the low/mid-level flow and related shear, scattered damaging winds and a few embedded tornadoes are possible wherever this line can become/remain surface based. The Slight Risk has been expanded southward to include more of the west-central FL Peninsula based on expectations for the broken line to impact this region amid greater low-level moisture/instability and sufficient deep-layer shear for organized convection. For more details on the near-term severe threat across parts of the FL Panhandle and southwest GA, reference Mesoscale Discussion 85.