Flash Flood — Lee, Kentucky

2021-07-11 · near St Helens, Lee, Kentucky

Event narrative

Flashing flooding issues were reported along Blaines Branch just off of Hwy 52 past the intersection with Robinson Hollow Road. Roughly 2 feet of water was over the road and some of the black top was removed. The road had to be closed due to the flooding and damage to the road surface. A video was also shared with the NWS Jackson, KY weather office by the Lee County EM of a culvert being washed away.

Wider weather episode

Several days of heavy to torrential rains and gusty winds were experienced across eastern Kentucky from July 9th through the 12th. A strong surface low pressure remained parked across Illinois to our WNW, with a frontal boundary expanding eastward and through Kentucky, sinking just south of the state to start the day on the 9th. During the day on the 9th and the 10th, the front began lifting northward through eastern Kentucky as a warm front, becoming the center for convective development, and also allowing for much deeper warm air and moisture advection into the region. As the front slowly continued just north of the state on the 11th and 12th, Kentucky found itself in the warm and unstable sector of the system, with showers and thunderstorms developing, peaking in coverage and intensity during the afternoon hours.

Given the warm environment, storms were generally low centroid and moisture laden, exhibiting well above normal PWats, in the 2 to 2.5 inch range. Soundings also showed shallow inverted V signatures, indicative of steep low level lapse rates and the ability to easily mix down higher winds aloft. Pulsy scattered convection with heavy rain and high wind gusts were the main concerns. Locations where multiple storms moved over saw high water and some instances of flash flooding. Other locations experienced thunderstorm wind damage as stronger winds transferred to the surface, especially as the storms were beginning the dissipating phase.

An 850 jet SW to NE, storms that NW to SE oriented were bowing.

View location on OpenStreetMap → (37.5810, -83.6835)

Source: NOAA Storm Events Database, event_id 964721. Narrative written by the NWS forecast office that issued the report.