Thunderstorm Wind — Liberty, Florida

2019-04-19 · near Bristol, Liberty, Florida

Event narrative

A power line was blown down onto Highway 20.

Wider weather episode

This event was characterized by a mid-level shortwave becoming negatively tilted in the Tennessee Valley and attendant surface low pressure. The strong wind field associated with this system included another anomalously strong low-level jet, with 925 hPa winds sampled on the 12Z/19 TAE Sounding around 40 knots! This advected warm, moist, and unstable air northward, ahead of a pre-frontal trough which served as a focusing mechanism for convection. Instability was initially lacking Thursday Night, but increased on Friday, with Mixed Layer CAPE ranging from 1-1.5k J/kg. Furthermore, the 12Z/19 TAE Sounding revealed Surface Based CAPE of nearly 2.4k J/kg, which is a record for the date per SPC Sounding Climatology! The instability and Bulk Shear (0-6 km) over 50 knots overcame the poorer mid-level lapse rates, and the QLCS intensified as it moved east of the Flint and Apalachicola Rivers on Friday. Despite Shear (0-1 km) around 35 knots on the 12Z/19 TAE Sounding, the hodograph revealed a more unidirectional wind within this layer, however there may have been slightly more veering based on the nearby observations from TLH.

View location on OpenStreetMap → (30.4400, -84.9400)

Source: NOAA Storm Events Database, event_id 820551. Narrative written by the NWS forecast office that issued the report.