Flash Flood — Washington, Utah

2020-08-23 · near St George, Washington, Utah

Event narrative

During the late evening and early nighttime hours, intense rainfall was observed in St. George. The St. George, UT Coop observer reported 2.00 inches of rainfall in two hours, corresponding to a recurrence interval of approximately 200 years. The Santa Clara River at St. George rose from 3 cfs to 1,586 cfs in 3 hours. Interstate 15 was closed in both directions, with five to six feet of water reported across roadways in the area producing additional road closures, including the Red Hills Parkway. Many cars were stalled and stranded, several sink holes were reported, and power outages occurred. St. George Rehabilitation was partially evacuated. Flood damage was reported in apartment complexes and basements. Monetary damage to public infrastructure was $3,082,501, with an additional $2,302,000 in damage to private property.

Wider weather episode

A thunderstorm complex moved across Washington County, including the City of St. George, during the evening hours, producing heavy rainfall and flash flooding, and an isolated severe wind gust.

View location on OpenStreetMap → (37.1165, -113.5876)

Source: NOAA Storm Events Database, event_id 915294. Narrative written by the NWS forecast office that issued the report.