Heavy Rain — Martinsville (c), Virginia

2020-08-21 to 2020-08-22 · near Martinsville, Martinsville (c), Virginia

Event narrative

The Cooperative Weather Observer in Martinsville, VA recorded a 24-hour rainfall total of 2.54 inches from thunderstorms that occurred during late morning of the 21st. This total sets a new rainfall record for the 22nd August, breaking the previous record of 1.41 inches set in 1962. Records for this station date back to September 1930.

Wider weather episode

Southwest winds aloft were responsible for carrying deep tropical moisture across the Piedmont during the morning of the 21st, while northeasterly flow near the surface was in place due to high pressure wedged against the eastern face of the Appalachians. The high moisture content across the Piedmont, with a precipitable water value of 1.77' measured from the morning sounding at KGSO, as well as very light mean winds, set the stage for slow-moving, highly efficient rainfall. This would be over soils that, in many areas, were 50-75 percent saturated to start the day due to earlier rainfall events per FLASH estimates.

Regarding the event, a flash flood warning was initially issued at 8:27 am after portions of northwest Henry County and the City of Martinsville received between 1.5 and 2.5 inches of rainfall since around 6:00 am. Training of storms producing heavy rain continued, and the warning was upgraded to a flash flood emergency at 10:15 am after reports were received of swift water rescues taking place and flood waters entering homes. In response to the flooding, Henry County officials declared a local State of Emergency to allocate funding and resources to help with the resulting property damage.

Numerous roads were closed due to flooding and/or debris flows, including these listed below. Flood waters were observed receding quickly by noon, with most roads that did not sustain damage or were blocked by debris opened by 3:00 pm.

* U.S. Route 220 South/Virginia Avenue from Mountain Top Court to Appalachian Drive/State Route 57 East and the ramp intersection due to flooding

* U.S. Route 220 North from Horsley Road/Virginia Avenue to Appalachian Drive/State Route 57 West due to flooding

* Route 665 East/West from dead end to Figsboro Road and State Route 108 due to downed tree

* State Route 174 East from State Route 108 to Beaver Hills Club Drive/Kings Mountain Road due to flooding

* State Route 174 West from FR-1008 to Jack Dalton Road/Route 1159 due to flooding

* Route 714 North/South from Kings Mountain Road/State Route 174 East to Figsboro Road/State Route 108 due to flooding

* Route 755 East/West from Fairystone Park Highway/State Route 57 to Alan Adale Drive/Fairystone Park Highway/State Route 57 due to flooding

* Route 703 North/South from Campbell Court/Fairystone Park Highway/Route 715/State Route 57 to Bassett Heights Road/Route 672 due to flooding

* Route 698 North/South from Jarrett Drive/Route 679 to John Henry Road/Out A Way Drive/Route 780 due to flooding

* Route 609 North/South from Artwood Drive/Wigginton Road/Route 1000 to Watson Drive/Route 943 due to flooding.

View location on OpenStreetMap → (36.7048, -79.8653)

Source: NOAA Storm Events Database, event_id 916079. Narrative written by the NWS forecast office that issued the report.