Marine Thunderstorm Wind · Atlantic South

Buoy 41004 measured a peak wind gust of 43 knots at 11 AM.

A severe quasi-linear convective system (QLCS) moved across coastal waters during morning hours of April 13, 2020 ahead of an approaching cold front. The environment ahead of the QLCS was unusually unstable for this time of day and year, with gulf moisture spreading upper 60 to near 70 dewpoints into a warm sector across the waters and mid level lapse rates around 7 C/km helping produce mixed layer convective available potential energy (MLCAPE) as high as 2000 J/kg. Within the warm sector, very strong vertical shear associated with a 50 knot plus low and mid-level jet, effective bulk shear around 70 knots, effective storm relative helicity in the 400-600 m2/s2 range, and VAD wind profiles displaying large, curved low-level hodographs were supportive of well organized convection and potentially embedded supercell thunderstorms in a QLCS capable of producing damaging winds and waterspouts. As the QLCS swept across the waters, severe thunderstorms produced high winds.