Flash Flood — St. Helena, Louisiana

2016-08-12 to 2016-08-13 · near Chipola, St. Helena, Louisiana

Event narrative

Sixteen to twenty inches of rainfall over a 2 day period led to widespread flash flooding in St. Helena Parish. As water drained into area rivers, rapid rises and record flooding occurred along the Amite and Tickfaw Rivers. As floodwaters rose, numerous high water rescues were necessary across the parish. Road closures due to high water were common and over 400 homes and businesses suffered various degrees of damage. A section of Louisiana Highway 10 near the Coleman Town community was overtopped with some of the road washed out. In Greensburg, flood waters rose high enough to enter the parish hospital. Two fatalities are attributed to the flash flooding. A 54 year old man drowned when his truck was submerged after being swept off a road east of Greensburg Friday afternoon. A 44 year old woman drowned when her vehicle was swept off Hwy 1045 near Montpelier Friday night.

Wider weather episode

A slow moving low pressure system brought widespread showers and thunderstorms to the area. The system tapped into deep tropical moisture resulting in very intense rainfall across a large portion of the area. Two-day rainfall totals of 10 inches or more were common across areas generally to the west and northwest of Lakes Pontchartrain and Maurepas. The heaviest rainfall occurred across a swath of East Baton Rouge, Livingston, and St. Helena Parishes, where 20 to 30 inches fell over a 48-hour period, topping the 0.1% annual exceedance probability. The heavy rainfall led to widespread flash flooding and record river flooding. Many of the broken records had been set during the flooding of April 1983. In total, 12 people died in southeast Louisiana as a result of the flooding. The event was also responsible for an estimated total of ten billion dollars in damage across southern Louisiana and southern Mississippi. This estimate includes impacts of both the initial flash flooding and the resultant river flooding.

View location on OpenStreetMap → (30.9990, -90.8260)

Source: NOAA Storm Events Database, event_id 656004. Narrative written by the NWS forecast office that issued the report.