A series of training thunderstorms produced extremely high rainfall across portions of Patrick and Carroll Counties in Virginia during the predawn hours of August 28th. This resulted in areas of flash flooding, mainly in the headwaters of the Smith River and the Ararat River, with extensive river flooding observed in Mount Airy, NC.
The event began with a stationary front draped near the border of Virginia and North Carolina early on the 28th as an upper level disturbance began passing across the lower Great Lakes, placing the central Appalachians in an area of favorite lift. The disturbance triggered a southeasterly wind shift across the foothills of the Blue Ridge in southern Virginia and northern North Carolina, bringing an increase of deep moisture northeast from the Piedmont of North Carolina. Precipitable water values were estimated to be
between 1.9 to 2.1 inches across Surry County by 3:00 am EDT on the 28th, while Mixed-Layer CAPE values remained around 500 J/Kg through much of the night.
Convection initiated after sunset on the 27th as a few slow-moving showers across southern Patrick County, Virginia. Coverage and intensity of the slow-moving activity only increased as the evening progressed, with a band of showers and embedded storms forming along the Highway 58 corridor by midnight, that was advancing northeast toward the crest of the Blue Ridge. In western Patrick County and southeast Carroll County, Virginia, 4 to 7 inches of rain fell across the entire headwaters of the Ararat River, with radar estimated values of around 9 inches near the town of Ararat, VA. he flooding progressed south into Mount Airy, NC, where the Ararat River flowed out of its banks and flooded areas of the town along the river channel, with the river cresting at 23.71 feet.

Flash Flood in SURRY, NORTH CAROLINA
From 28-AUG-23 03:00:00 to 28-AUG-23 09:00:00 (EST-5)
Location: SALEM
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Social Media

Extensive flooding was observed along the Ararat River in the town of Mt. Airy, NC on the morning of the 28th due to 6 to locally 10 inches or rainfall across the headwaters in Patrick County during the predawn hours of the day.  Among the observed impacts of this river flooding, the bridge along White Sulphur Springs Road over the Ararat River was impassible for several hours.  Further downstream, water from the river spread out to cover Riverside Drive and E. Oak Street, with nearly all of Riverside Park completely flooded.  A gas station at the corner of E. Pine Street and Riverside Drive was surrounded by flood waters, though water did not enter the building.  On the south end of town, Hamburg Street was flooded up to a foot deep over the road.  Property damage is the estimated cleanup cost of the flooding, as well as any minor damage the flooding caused.

Flash Flood in SURRY, NORTH CAROLINA
From 28-AUG-23 03:00:00 to 28-AUG-23 09:00:00 (EST-5)
Location: SALEM
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

The Ararat River at Mt. Airy, NC (ARLN7) crested at 23.71 feet, rising above the moderate flood stage of 22 feet. This is the current flood-of-record for this gage, which was recently installed.  The river rose nearly 10 feet in the six hours leading up to the crest due to 6+ inches of rain within mainly a 6-hour period across the entire Ararat basin in Carroll and Patrick Counties.  Discharge measurements are not performed at this location and no rating table is available.