EF1 tornado in Allendale County, South Carolina

A National Weather Service Storm Survey Team confirmed an EF-1 tornado with an estimated maximum wind speed of 109 mph in Allendale County, South Carolina. High resolution satellite data combined with survey information

indicated the tornado touched down just west of Wells Branch Road, near the Allendale/Barnwell County Line. In this area, the tornado was strongest, snapping and uprooting many trees. The tornado then weakened while continuing an east path across a remote area, before dissipating near the CSX Railroad line, still within Allendale County, South Carolina.

A severe quasi-linear convective system (QLCS) moved through southeast South Carolina during the afternoon into early evening hours of April 5, 2022 as a mid-level shortwave ejected rapidly across the region in advance of a surface cold front. The environment ahead of the QLCS was favorable for severe local storms as southerly winds spread mid 60 dewpoint temperatures into a warm sector across the Southeast United States and favorable mid-level lapse rates and lifted index values helped produce mixed layer convective available potential energy (MLCAPE) as high as 1500-2000 J/kg during peak surface heating across southeast South Carolina. Within the warm sector, strong shear associated with 50-70 knot low and mid-level jets beneath the left front quadrant of a 120 knot upper-level jet, 0-6 km bulk shear around 50 knots, and 0-3 km storm relative helicity in excess of 300 m2/s2 were supportive of well organized convection and potentially embedded supercell thunderstorms in a QLCS capable of producing a prolonged path of damaging winds and strong long-track tornadoes. As the QLCS swept through southeast South Carolina, a few discrete supercell thunderstorms became exceptionally strong near or just ahead of the main line of thunderstorms, producing damaging winds, moderate size hail, and strong tornadoes.

A total of 5 confirmed tornadoes occurred across southeast South Carolina in the Charleston County Warning Area, including two long track EF-3 tornadoes, one which developed in Allendale County southwest of Allendale, SC and ended near Sycamore, SC with an approximately 13.3 mile path, and a second tornado which began in Allendale County near Ulmar, SC, then crossed into the Columbia County Warning Area in Bamberg County at peak strength, before continuing and ending in Orangeburg County with an approximately 34.8 mile path. The South Carolina Forestry Commission estimated 3,389 forest acres damaged by strong winds and tornadoes in Allendale County alone during the severe weather outbreak.