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.

Heavy Rain in HENRY, VIRGINIA
From 21-AUG-20 06:00:00 to 21-AUG-20 09:00:00 (EST-5)
Location: BASSETT FORKS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A personal mesonet station recorded 4.48��� for a storm-total, with about 3.4 of it falling during the period 7 am to 10 am. This amount represented around a 100-yr event for the 3-hour duration per NOAA Atlas-14 estimates.

Heavy Rain in MARTINSVILLE (C), VIRGINIA
From 21-AUG-20 06:00:00 to 22-AUG-20 06:00:00 (EST-5)
Location: MARTINSVILLE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

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.

Heavy Rain in HENRY, VIRGINIA
From 21-AUG-20 05:00:00 to 21-AUG-20 11:00:00 (EST-5)
Location: BASSETT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A home mesonet station near Reed Creek recorded a storm total of 5.67 inches of rainfall from training thunderstorms, the vast majority of which fell during a 6-hour period between 6 am and noon on the 21st.  This rainfall amount equates to roughly a 100-year rainfall event per NOAA Atlas 14 point frequency estimates.

Heavy Rain in HENRY, VIRGINIA
From 21-AUG-20 05:00:00 to 21-AUG-20 11:00:00 (EST-5)
Location: BASSETT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A home mesonet station near Bassett recorded a storm total of 3.39 inches of rainfall from training thunderstorms, the vast majority of which fell during a 6-hour period between 6 am and noon on the 21st.

Heavy Rain in HENRY, VIRGINIA
From 20-AUG-20 06:00:00 to 22-AUG-20 06:00:00 (EST-5)
Location: BASSETT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

A CoCoRaHS station recorded at 2-day total of 4.08 inches rainfall on the mornings of the 21st (2.31 inches) and the 22nd (1.77 inches).

Flood in DANVILLE (C), VIRGINIA
From 21-AUG-20 13:20:00 to 21-AUG-20 14:45:00 (EST-5)
Location: DANVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Poor drainage issues caused Union Street to be closed due to standing water in the roadway.  The intersection of Jefferson Street and Pine Street was also closed by standing water.

Flash Flood in HENRY, VIRGINIA
From 21-AUG-20 06:50:00 to 21-AUG-20 11:30:00 (EST-5)
Location: PHILPOTT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Runoff from very 1.5 to 2 inches of rain within a 2-hour period caused Blackberry Creek to rise rapidly out of its banks and cause flooding on Blackberry Road.

Flash Flood in HENRY, VIRGINIA
From 21-AUG-20 07:44:00 to 21-AUG-20 13:15:00 (EST-5)
Location: BASSETT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Widespread flooding was observed in the Bassett and Stanleytown communities.  This includes flooding of Riverside Drive as Blackberry Creek rose out of its banks, as well as flooding at the intersection of Oakcrest Circle and Winnfield Road where a tributary of Little Reed Creek overflowed its banks.  Little Reed Creek also flooded out of its banks, overflowing onto Highway 220, including numerous businesses along the highway as far south as where the creek merges with Reed Creek and then empties into the Smith River.  There were reports that as many as 40 automobiles were trapped along Highway 220 by the flood, with a few occupants needing assistance to evacuate the vehicles.  Most people were able to leave the vehicles on their own.  Flood waters of Little Reed Creek were intense enough to damage the bridge that crosses the creek along Edgewood Drive. Portions of the Great Road were closed for several hours due to flooding, as was Daniels Creek Road near Reed Creek.  Numerous other roads and buildings were impacted as well to varying degrees.

Flash Flood in MARTINSVILLE (C), VIRGINIA
From 21-AUG-20 10:42:00 to 21-AUG-20 10:42:00 (EST-5)
Location: MARTINSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Radar precipitation estimates and personal mesonet stations indicate that between 1.75 and 2.5 inches of rain fell in the Chatmoss area, much of this rain falling in a 1-hour period across soils that were near saturation from recent rainfall.  These amounts were anywhere from an 8- to 15-year rainfall event per FLASH estimates.  Runoff from this rainfall caused flooding along Spruce Street, near Irisburg Road, making the road impassible until the floodwaters receded.

Debris Flow in HENRY, VIRGINIA
From 21-AUG-20 09:26:00 to 21-AUG-20 09:26:00 (EST-5)
Location: COLLINSVILLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Radar rainfall estimates and nearby personal mesonet station indicated that 2 to 3 inches of rain fell across the Collinsville community in a 2 to 3 hour period of time.  This heavy rain caused a debris flow to occur along Figsboro Road near the intersection of Kings Mountain Road, causing the road to be blocked and impassible until maintenance crews could clear the debris.