EF0 tornado in St. Helena Parish, Louisiana

An EF-0 tornado with maximum sustained winds of 85 mph rapidly developed along a line of thunderstorms near Hwy 1047 and Deer Creek Rd. Minor tree damage was noted in this portion of the track. The tornado exited St Helena Parish and entered Tangipahoa Parish 1 mile north of Highway 1048.

Environmental conditions favorable for a QLCS (Quasi-Linear Convective System) tornado event developed across southeast Louisiana and southern Mississippi during the afternoon and evening hours of March 11th. An upper-level storm system moving east from Texas overspread a very moist and increasingly unstable air mass in place across the region. At the same time, intense low-level wind shear and strong atmospheric spin developed as southerly winds strengthened ahead of an approaching line of storms with bowing segments.

The combination of rich Gulf moisture, strong low-level atmospheric spin, and a fast-moving line of thunderstorms created an environment supportive of embedded rotating circulations along the leading edge of the QLCS. As that line moved west to east across the local area, several rapidly developing tornadoes formed within these circulations. A total of 8 tornadoes were confirmed across southeast Louisiana, including 2 with path lengths exceeding 10 miles. Well over a dozen additional reports of damaging straight-line winds were also received.