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.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 07:51:00 to 13-APR-20 08:16:00 (EST-5)
Location: FOLLY BEACH
Magnitude: 49.00 MG
Reported by: Mesonet

The Weatherflow sensor at Folly Beach Pier measured a peak wind gust of 49 knots at 751 AM.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:04:00 to 13-APR-20 08:09:00 (EST-5)
Location: SULLIVANS ISLAND
Magnitude: 42.00 MG
Reported by: Mesonet

The Weatherflow sensor at Sullivans Island measured a peak wind gust of 41 knots at 804 AM.

Marine Thunderstorm Wind in CHARLESTON HARBOR, ATLANTIC SOUTH
From 13-APR-20 08:06:00 to 13-APR-20 08:16:00 (EST-5)
Location: FORT SUMTER
Magnitude: 49.00 MG
Reported by: Mesonet

The Weatherflow sensor at the Fort Sumter Range Front Light measured a peak wind gust of 49 knots at 806 AM.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 09:08:00 to 13-APR-20 09:09:00 (EST-5)
Location: ISLE OF PALMS
Magnitude: 35.00 MG
Reported by: Buoy

The Capers Nearshore Buoy measured a wind gust of 35 knots.

Marine Thunderstorm Wind in SOUTH SANTEE RIVER TO EDISTO BEACH SC FROM 20 TO 40 NM, ATLANTIC SOUTH
From 13-APR-20 09:30:00 to 13-APR-20 09:31:00 (EST-5)
Location: EDISTO BUOY (41004)
Magnitude: 35.00 MG
Reported by: Buoy

Buoy 41004 measured a wind gust of 35 knots.

Marine Thunderstorm Wind in SOUTH SANTEE RIVER TO EDISTO BEACH SC FROM 20 TO 40 NM, ATLANTIC SOUTH
From 13-APR-20 09:50:00 to 13-APR-20 09:51:00 (EST-5)
Location: EDISTO BUOY (41004)
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

Buoy 41004 measured a wind gust of 35 knots.

Marine Thunderstorm Wind in SAVANNAH GA TO ALTAMAHA SD GA OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 07:54:00 to 13-APR-20 07:55:00 (EST-5)
Location: TYBEE ISLAND
Magnitude: 36.00 MG
Reported by: Mesonet

The Weatherflow sensor at Tybee Island South measured a wind gust of 36 knots.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:00:00 to 13-APR-20 08:01:00 (EST-5)
Location: FOLLY BEACH C-MAN (FBIS1)
Magnitude: 34.00 MG
Reported by: Mesonet

The sensor at Folly Beach North End measured a wind gust of 34 knots.

Marine Thunderstorm Wind in EDISTO BEACH SC TO SAVANNAH GA OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:08:00 to 13-APR-20 08:09:00 (EST-5)
Location: FRIPP ISLAND
Magnitude: 39.00 MG
Reported by: Buoy

The Fripp Nearshore Buoy measured a wind gust of 39 knots.

Marine Thunderstorm Wind in SAVANNAH GA TO ALTAMAHA SD GA OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:04:00 to 13-APR-20 08:05:00 (EST-5)
Location: TYBEE ISLAND
Magnitude: 36.00 MG
Reported by: Mesonet

The Weatherflow sensor at Tybee Island South measured a wind gust of 36 knots.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:15:00 to 13-APR-20 08:16:00 (EST-5)
Location: ISLE OF PALMS
Magnitude: 39.00 MG
Reported by: Mesonet

A 39 knot wind gust was measured at the FW1744 Isle of Palms wind sensor.

Marine Thunderstorm Wind in S SANTEE R TO EDISTO BEACH SC OUT 20NM, ATLANTIC SOUTH
From 13-APR-20 08:07:00 to 13-APR-20 08:22:00 (EST-5)
Location: ISLE OF PALMS
Magnitude: 48.00 MG
Reported by: Mesonet

The Weatherflow sensor at Isle of Palms measured a peak wind gust of 48 knots at 812 AM.

Marine Thunderstorm Wind in SOUTH SANTEE RIVER TO EDISTO BEACH SC FROM 20 TO 40 NM, ATLANTIC SOUTH
From 13-APR-20 10:50:00 to 13-APR-20 11:10:00 (EST-5)
Location: EDISTO BUOY (41004)
Magnitude: 43.00 MG
Reported by: Buoy

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