Thunderstorm Wind in Lancaster County, South Carolina

Lancaster County dispatch reported three trees down in the town of Kershaw. Time estimated by radar.

An upper trough and frontal boundary was approaching the region from the west. The atmosphere was quite unstable with surface based CAPE around 3000-4000 J/kg, 3000 J/kg of mixed layer CAPE. Wind shear was relatively weak with effective bulk shear less than 25 knots and atmospheric moisture was high with precipitable water values around 2 inches and dewpoints in the mid to upper 70s. Relatively weak wind shear combined with the very moist and unstable air mass supported slow moving and training thunderstorms conducive to flash flooding. Several days of rainfall preceding this event contributed to the occurrence and severity of flash flooding in the Blythewood area and north of downtown Columbia due to saturated ground.