Heavy Rain — Giles, Virginia

2022-05-23 to 2022-05-24 · near Penvir, Giles, Virginia

Event narrative

An automated weather station (Weather Underground: KVANARRO14) observed a 24-hour rainfall total, ending 8 AM EDT, of 3.99 inches. Rainfall rates remained mostly below 0.5 per hour but, at times, were as high as 1 per hour. This amount is between a 10- and 25-year rainfall event per NOAA Atlas 14 point frequency estimates for this duration. Runoff from this rainfall eventually flows into the Wolf Creek.

Wider weather episode

Tropical moisture was forced northward from the Gulf of Mexico on May 23rd, overrunning a cold front draped across central North Carolina. High pressure extended southward across the Mid-Atlantic, wedged against the eastern face of the Appalachian chain, resulting in upslope east to southeasterly windflow from the Piedmont into the mountains. Atmospheric moisture was abundant, given strong southerly flow around low pressure near the Gulf coast transporting moist air rapidly northward, resulting in precipitable water values ranging from 1.3 to 1.5 inches across the mountains of western Virginia, roughly 2 standard deviations above normal for the month of May. Rainfall totals across the Upper Bluestone River and Wolf Creek basins varied from 2.5 to 3.5 inches over an 18 hour period. However, the stabilizing effect of the high pressure limited instability, preventing convective development. As such, rainfall was prolonged, however rainfall rates seldom exceeded 0.5 inches per hour.

View location on OpenStreetMap → (37.2970, -80.8770)

Source: NOAA Storm Events Database, event_id 1019963. Narrative written by the NWS forecast office that issued the report.