Flash Flooding and Debris Flows in Virginia, October 11 to 15, 2018

The Danville ASOS rain gage (DAN) failed due to a power outage during the fierce storm, but the backup site measured 6.00 inches for October 11th (24-hour period ending at midnight). This is the highest daily rainfall ever recorded at Danville with data back to 1916. The previous record was 5.81 inches on August 27, 2008.

The New River at Glen Lyn (GLLV2) crested at 19.47 feet (121000 cfs) on the morning of the 12th. Major flood stage is 18 feet. It was the 3rd highest reading at this location since USGS records began in 1940 and the highest since January 16, 1995 (19.83 feet). In terms of flood frequency it fell near a 25-year event (0.04 annual chance flood). There were considerable impacts along the New River including several mobile home parks flooded.

Water was reported over Route 100 due to flooding from Walker Creek. The gage at Bane (BANV2) briefly touched minor flood stage of 11 feet (7,800 cfs) very early on the 11th in response to the PRE (Predecessor Rainfall Event) and then had a more significant second rise from the rains directly associated with Michael, reaching a crest of 13.46 (12,000 cfs) feet early on the 12th. Moderate flood stage is 14 feet.

The COOP observer ay South Boston (SBNV2) measured 5.20 inches for the 24-hour period ending 700 AM local time, October 12, 2018. This was the 5th highest 24-hour rainfall on record for this station and easily the highest in October. Complete records date back to 1980 at this station.

The COOP observer at Keysville 2 S (KYSV2) measured 9.02 inches for the 24-hours ending at 700 AM local time, October 12, 2018. This was the highest 24-hour rainfall amount at this station with partial data back to 1979. The old record was 5.50 inches in July, 2005. In addition, the 9.02 inches is the 3rd highest 24-hour amount for any COOP station in the climate record for the NWS Blacksburg. According to the observer, most of this rain fell in about a 3.5 hour period on the afternoon of the 11th. For the 24-hour duration 9.02 inches falls into the 90 percent confidence interval (8.19-10.2 inches) for a 200-year (.002 annual chance event). For a duration of even 6 hours (being very conservative) the rainfall frequency was in excess of the 1,000 year event (.001 annual chance).

The CoCoRaHS site at Saxe 4.3 SE (VA-CH-1) measured 6.15 inches in 24-hours ending 700 AM local time, October 12, 2018.

The CoCoRaHS site at Brookneal 2.9 E (VA-CM-10) measured 4.90 inches for 24-hour period ending at 700 AM local time, October 12, 2018.

The CoCoRaHS observer at Cave Spring 2.4 SSW (VA-RN-1) measured 5.40 inches of rain in the 24-hours ending at 700 AM local time on the 12th. Most of the rain fell in thunderstorms over several hours from mid-morning to early afternoon on the 11th. Widespread flash flooding was reported in the County.

The CoCoRaHS observer at Roanoke 5.8 SW (VA-RN-13) measured 5.41 inches of rain in the 24-hours ending at 0700 local time on the 12th. Most of this fell in thunderstorms over several hours from mid-morning to early afternoon on the 11th. Widespread flash flooding was reported in the County.

The COOP observer at Chatham (CHMV2) measured 4.52 inches for the 24-hour period ending 700 AM local time, October 12, 2018. This was easily a date record but also the 10th highest 24-hour rainfall on record for this station and second highest in October (after 6.00 inches on October 3, 1927). Nearly complete rainfall records date back to 1922 at this station.

The CoCoRaHS observer at Meadows of Dan 2.3 E (VA-PR-5) measured 5.29 inches of rain in the 24-hours ending at 0700 local time on the 12th. Flash flooding was reported in the County.

There were several reports of flash flooding in Wythe County with a number of roads closed in Wytheville and the eastern portions of the county as early as 900 AM local time. Reed Creek reportedly flooded East Lee Highway bear Carter's Park. The New River trail was flooded near Max Meadows although probably from the flooded New River itself.

County-wide flooding was reported by law enforcement with at least seven roads were reported closed across Floyd County. An Amateur Radio report said Hale Road in the Terry's Fork area near Check was closed due to flooding and several creeks were well out of their banks. Four vehicles were abandoned in high water on Buffalo Mountain Road, Spangler Mill Road, Daniel's Run Road and Stonewall Road.

Galax City was included in a Presidential Major Disaster declaration due to the severe flooding associated with Tropical Storm Michael. There were numerous flash flood reports across the City of Galax starting as early as 1100 AM local time and continuing for several hours. Numerous roads were closed and damaged and several evacuations took place.

Roanoke County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. Extremely high sustained rain rates (2-4 inches per hour) became concentrated across parts of the Roanoke area between 1100 AM to 200 PM local time. At 243 PM a rare Flash Flood Emergency was issued for Roanoke City, City of Salem and Roanoke County after consultation with local Emergency management amidst reports of numerous water rescues in the area. Radar and rain gages showed 3 to 6 inches of rain during this period from the southern part of Roanoke City into the adjacent portions of Roanoke County. There were numerous reports of flash flooding across mainly the South County area where the heaviest rains fell, 5 to 6 inches in some locations. Mudlick Creek flooded across Cresthill Drive to a depth of at least one foot. Several small mudslides occurred and numerous roads were closed. There was also reports of high water rescues in several areas including a motorist stranded on Ferguson Valley Road along Back Creek. The USGS gage on Back Creek near Dundee (BCKV2) crested at 23.09 feet (17,000 cfs) in the evening of the 11th at the 2nd highest stage and discharge since records began in 1971 and only slightly below the record flood in November 1985 of 25. 1 feet.

Extremely high sustained rain rates (2-4 inches per hour) became concentrated across parts of the Roanoke area between 1100 AM to 200 PM local time. At 243 PM a rare Flash Flood Emergency was issued for Roanoke City, City of Salem and Roanoke County after consultation with local Emergency management amidst reports of numerous water rescues in the area. Radar and rain gages showed 3 to 6 inches of rain during this period from the southern part of Roanoke City into the adjacent portions of Roanoke County. Numerous water rescues were conducted in the Roanoke City including at the Ramada Inn along flooded Franklin Road. Numerous roads were flooded across the city.

Wards Mill Branch was flooded and out of its banks, flowing across Coal Creek Road.

Brentwood Community (KVADANVI13) mesonet site reported an hourly precipitation amount of 4.66 inches between 3:04 and 4:04 PM local time with a daily total of 7.68 inches when the power failed. Almost all the rain fell after 11:30 AM. 4.66 inches in 1 hour exceeds the 1000-year (.001 annual chance) precipitation frequency uncertainty interval listed in NOAA Atlas 14 for Danville.

Montgomery County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. At least four roads were reported closed across the county including in the Ellett Valley area. At least six inches of moving water was reported over Toms Creek Road near Redbud Road and Toms Creek was out of its banks and flooding Meadowbrook Road in Blacksburg. Elsewhere in Montgomery County 13-year-old became trapped in an all-terrain vehicle in a flooded creek and the New River Valley swift-water rescue team helped to rescue the teenager.

All the animals were evacuated from the Galax Veterinary Clinic on Stockyard Road after a mudslide along the road above the clinic brought down a power pole and caused its lines to fall onto the clinic. The Galax Volunteer Fire Department evacuated both pets and staff from the building.

Wind gusts estimated to be in the 35 to locally near 50 mph range were common during the passage of Tropical Storm Michael across Carroll County. Numerous trees were blown down across the county, blocking several roads. At one point, fallen trees blocked U.S. Highway 52 in both directions. Multiple trees were also blown down near the intersection of Orchard Gap Road and Wards Gap Road. Numerous power lines were also blown down, resulting in between power outages for at least 1,000 customers across the county.

Extremely high sustained rain rates (2-4 inches per hour) became concentrated across parts of the Roanoke area between 1100 AM to 200 PM local time. At 243 PM a rare Flash Flood Emergency was issued for Roanoke City, City of Salem and Roanoke County after consultation with local Emergency management amidst reports of numerous water rescues in the area. Radar and rain gages showed 3 to 6 inches of rain during this period from the southern part of Roanoke City into the adjacent portions of Salem. At least 25 roads or intersections were closed at some point due to flooding in Salem. Mason Creek flooded several mobile home communities in Salem as shown on social media. More than 40 people were evacuated from threatened homes. Mason creek crested at the upstream IFLOWS gage (MSCV2) at 7.90 feet around noon, NWS Minor flood stage is 7 feet. The state of Virginia declared Salem as a Small Business Administration Disaster area.

Several roads were closed in Pulaski County and the town due to flooding. Peak Creek flooded several roads including Crescent Street, Lottier Bottom Road and Main Street. The creek crested at around 8 feet on a staff gage in town calibrated to the IFLOWS gage (PCRV2) which was out of service during the event. Minor flood stage is 8 feet.

Numerous roads were closed due to flooding in Carroll County. A daycare center was evacuated near a small creek flooding along Fisher Road. Brush Creek near Ivanhoe was reported out of its banks and entering several nearby homes.

Rainfall of 7.75 inches was measured at the Pittsylvania County 911 Center between 1240 PM and 540 PM local time.

Franklin County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. Rainfall of 3 to 6 inches occurred in several hours with flash flooding across much of the county. At least eight roads were reported blocked by flowing water across the county with significant damage to infrastructure.

Strong wind gusts, the highest observed being a 52 mph gust measured along Hazelwood Terrace near the community of Stewartsville, were common during the passage of Tropical Storm Michael. These gusty winds, when combined with the effects of saturated ground due to heavy rain from the storm, resulted in numerous trees and power lines down across the county. Gusts as high as 32 mph were measured in the community of Moneta.

Strong wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael. The highest measured gust from Blue Ridge Airport (KMTV) was 31 mph, however the AWOS was not reporting for much of the day and may have missed stronger gusts. Hundreds of trees were reported down across the county, with some landing on homes, trapping their occupants inside. In addition, numerous power lines were blown down, resulting in several power outages across the county.

Wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael, though one mesonet site reported a gust of 52 mph at around 3:30 pm EDT. Many of the mesonet sites lost power that day, so higher gusts are possible. The gusty winds, when combined with the effects of saturated ground due to heavy rain, resulted in hundreds of trees and power lines down across the county. Trees fell on top of at least two homes and several automobiles in the City of Danville, causing extensive structural damage. At one point, at least 20,000 residents were without power due to the storm.

Wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael, with the highest measured gust being 30 mph at the Virginia Tech/Montgomery Executive Airport (KBCB). The gusty winds blew down dozens of trees across the county, some of which blocked roads. Several power lines were also blown down, resulting in power outages for several hundred customers.

Wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael across Floyd County. These gusty winds, when combined with the effects of saturated ground due to heavy rain from the storm, resulted in dozens of trees blown down across the county, some of which blocked roads. Several power lines were blown down as well, resulting in power outages which affected at least 1,000 customers across the county.

Wind gusts estimated to be in the 30 to 40 mph range, with locally higher gusts, were common during the passage of Tropical Storm Michael. These gusty winds, when combined with the effects of saturated ground due to heavy rain from the storm, resulted in dozens of trees and power lines down across the county. As many as a dozen trees were observed blown down in the Baywood Community.

Downpours from Michael dropped 3 to 6 inches of rain in a just a few hours Henry County causing numerous road closures starting as early at 100 PM local time. There were several water rescues from cars stranded in the water, including one on Reeves Road near Martinsville.

The South Fork of the Roanoke River near Shawsville (SHAV2) crested at 9.18 feet (7880 cfs) on the afternoon of the 11th. Major flood stage is 9 feet. It was the 4th highest reading at this location since USGS records began in 1961. In terms of flood frequency it fell near 10-year event (0.10 annual chance flood). Several roads were closed near the river and homes threatened.

The Roanoke River at Glenvar (GNVV2) crested at 17.10 feet (18600 cfs) on the evening of the 11th. Major flood stage is 16 feet. Several roads were closed near the river but it is unclear if homes or structures were affected. It was the 4th highest reading at this location since USGS records began in 1992 and the highest since September 28, 2004 (12.45 feet) with the remains of Hurricane Jeanne. In terms of flood frequency it near 10-year event (0.10 annual chance flood) per USGS studies.

The Roanoke River at Roanoke gage (RONV2) crested at 16.64 feet on the afternoon of the 11th, above the Major flood stage of 16 feet. It was the 7th highest crest since the current datum was established in 1937 and the highest since September 28, 2004 when the river reached 17.82 feet as the remains of Hurricane Jeanne swept through the area. In terms of flood frequency the event fell roughly between a 10- and 25-year event (0.10-0.04 annual chance flood).

Heavy rains of 3 to 6 inches caused numerous creeks to escape their banks forcing the closure of several primary and secondary roads. The river gage on the Smith River near Woolwine (SMWV2) showed a rise in less than six hours to a crest of 12.15 feet, Minor flood stage is 9 feet and Moderate flood stage 11 feet. This was the 4th highest reading at this gage since data started there in 1995 and was roughly a 5-year annual recurrence interval (0.10 annual exceedance probability).

News reports showed a large mudslide along East Stuart Drive that closed the road for several hours.

The New River at Radford (RDFV2) crested at 23.83 feet, over the Major flood stage of 20 feet late on the 11th. The peak discharge of 109,-000 cfs was very close to a 25-year event (.04 annual chance flood) per USGS studies. Several roads close the river were flooded.

Pittsylvania County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. Rainfall of 4 to 8 inches in several hours triggered widespread flash flooding across the county with numerous roads closed and extensive damage. A man lost his life when his automobile was washed off Sandy Creek Road near the 600 block during intense flooding along Sandy Creek. Media reports indicate the incident occurred around 330 PM local time, with one witness observing that water was flowing rapidly at least two feet above the road surface.

Wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael. These gusty winds, when combined with the effects of saturated ground due to heavy rain from the storm, resulted in over a dozen trees and power lines down across the county.

The USGS automated Data Collection Platform located at the Roanoke (Staunton) River gage near Randolph (RNDV2) measured 4.73 inches in 3 hours and 5.78 inches in 4 hours. For the 3-hour duration the 500-year recurrence confidence interval (.002 annual chance rainfall) is 4.41-5.92 inches.

The Roanoke River at Lafayatte (LAAV2) crested at 12.44 feet (16100 cfs) on the evening of the 11th. Moderate flood stage is 11 feet. It was the 6th highest reading at this location since USGS records began in 1944 and the highest since September 28, 2004 (12.45 feet) with the remains of Hurricane Jeanne. In terms of flood frequency it fell between a 10- and 25-year event (0.10-0.04 annual chance flood).

The New River flooded with the gage at Ivanhoe (IVNV2) rising above the Moderate flood stage of 19 feet, and reaching a peak of 20.05 feet (53100 cfs) on the afternoon of the 11th. This was the highest stage in over 40 years, since November 7, 1977 when the river reached 28.88 feet. According to USGS studies flooding from Michael was between a 10- and 25-year flood event (0.10 to 0.04 annual chance flood). Several roads close to the river were flooded and closed including Ivanhoe Road in Ivanhoe.

The New River at Allisonia (ALSV2) flooded, cresting above the Major flood category (14 feet) at 15.12 feet (99000 cfs) the night of the 11th. It was the highest stage since January 15, 1995 (16.56 ft.) and was approximately a 25-year flood event (.04 annual chance event) per USGS studies. Several roads close to the river were flooded and closed including Clarks Ferry Road and Julia Simpkins Road. Fllooding from the rive was reported along portions of Claytor Lake.

Several large trees were blown down by severe straight-line winds in the Ballou Park area of the City of Danville.

Campbell County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. There were several reports of flash flooding on the afternoon of the 11th with roads closed and verified flood damages exceeded $300 thousand.

The Sandy River near Danville (SDRV2) crested at 11.46 feet (14,000 cfs) on the afternoon of the 11th. Moderate flood stage is 10 feet. It was the highest reading at this location since USGS records began in 1943, although nowhere close to the discharge in the record August 1940 flood (23,000 cfs). In terms of flood frequency it fell near 25-year event (0.04 annual chance flood) according to USGS reports.

Heavy rains led to some flash flooding as to 2 to 3 inches fell in a short period. Lynchburg Airport ASOS (LYH) set a daily record rainfall for October 11th of 2.58 inches, with records back to 1893. The old record was 1.76 inches in 1990. Flooding was reported along a Ivy Creek with water flowing across Ivy Drive. City of Lynchburg officials activated the Emergency Action Plan for College Lake dam early Thursday as a result of the heavy rain but did not have to evacuate any residents or businesses downstream of the dam along Blackwater Creek. Several other roads were reported closed in Lynchburg including Greenwood Drive where it crosses Ivy Creek.

At least twenty trees, as well as several power lines, were blown down across portions of Charlotte County as very heavy rainfall associated with thunderstorms which developed in one of the feeder bands of Tropical Storm Michael allowed strong winds aloft to mix down to the surface.

Appomattox County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. Purdums Branch was several feet out of its banks and flooding apartments along Red House Road. In the town of Appomattox, a woman and boy were rescued after fast-moving water trapped the two in a creek behind their home on Church Street. A team of about 17 first responders with the Concord Appomattox Swiftwater Team responded to the rescue effort around 4:45 PM Local time. The two victims were quickly pulled from the waters without injury according to news reports.

The Dan River at Danville (DVLV2) crested at 30.01 feet (50300 cfs) on the evening of the 11th. Major flood stage is 25.5 feet. It was the highest reading at the current gage location since USGS records began in 1996 beating the previous record of 28.65 feet set on September 6, 1996 with the remains of Hurricane Fran. In terms of flood frequency (using regional regression equations) it fell between a 25-and 50-year event (0.04-0.02 annual chance flood). Significant flooding took place in Danville.

Wind gusts estimated to be in the 25 to 35 mph range were common during the passage of Tropical Storm Michael. These gusty winds, when combined with the effects of saturated ground due to heavy rain from the storm, resulted in over a dozen trees and power lines down across the county. One of the the fallen trees landed on a home along Andersonville Road, causing structural damage.

Numerous trees were blown down by severe straight-line winds along Charlie Brown Lane.

The Roanoke River through Salem flooded due to the heavy rainfall from Michael and the predecessor rainfall event. Several roads were closed and businesses affected by the flood waters. The Riverwalk Apartments along the Roanoke River in Salem were evacuated and 42 units received flood damage. The crest at the Salem Pump Station IFLOWS gage (SPSV2) was 14.6 feet very early on the 12th, just over the Moderate flood stage of 14 feet and well above Minor flood stage of 7 feet. It was the 3rd highest crest at this gage in the existing record back to 1972 and the highest since the November 1985 flood when the river reached 20.5 feet at this location.

A bridge over Catawba Creek on Hogan Hollow Road (Route 737) was reportedly underwater. The USGS gage on Catawba Creek near Catawba (CTWV2) crested at 7.92 feet (Minor flood stage is 7 feet), its highest level since September, 2004 when it reached 10.3 feet.

At least fifteen trees were blown down across portions of Buckingham County as very heavy rainfall associated with thunderstorms which developed in one of the feeder bands of Tropical Storm Michael allowed strong winds aloft to mix down to the surface.

Halifax County was included in a Presidential Major Disaster declaration due to the severe flooding associated with Tropical Storm Michael. Rainfall of 4 to 8 inches in several hours triggered widespread flash flooding across the county with numerous roads closed and extensive damage. County officials described it as 'the worst, most devastating storm we've ever seen in the county'. The 911 dispatch center had more than 300 calls for assistance between 5:00 and 7:00 PM on the 11th and more than 700 by 7:00 AM the next day Among the reports received was Lawless Creek as much as 300 feet out of its banks and flooding a church. News photos showed a portion of Pumping Hill Road near Nathalie completely destroyed. Several water rescues were made, including one on Terry’s Bridge Road near Scottsburg on Friday morning the 12th. A debris flow closed a portion of Route 58 in southwest Halifax.

Danville City was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. Catastrophic flash flooding occurred across the City of Danville as extreme rains of 4 to 8 inches in several hours fell. Two people were killed in Danville after being were caught inside vehicles in the floodwaters and were pulled under rising waters as rescuers struggled to reach them. The first was 53-year old man that occurred at 500 PM local time in the 100 block of Colonial Court. The second occurred around 1020 PM on Goodyear Boulevard, as a 60-year old woman was trapped in her car in floodwaters and drowned. There were at least a dozen other high water rescues reported several of these along Riverside Drive where water was reported up to four feet deep. There was severe road and property damage across Danville with costs running into the millions of dollars. According to an early assessment from the Danville Fire Chief, five properties were completely destroyed, 19 sustained major damage, 55 received minor damage and 117 structures were affected.

The Dan River at South Boston (SBNV2) crested at 31.36 feet (50900 cfs) on the afternoon of the 13th. Major flood stage is 29 feet. It was the 6th highest reading at this gage since records began in 1924 and the highest since September 8, 1996 (33.32 feet) during the remains of Hurricane Fran. In terms of flood frequency it fell near a 10-year event (0.10 annual chance flood). Significant flooding took place in the South Boston area.

The Dan River at Paces (PCEV2) crested at 31.36 feet (55400 cfs) early morning on the 13th. Major flood stage is 27 feet. It was the 4th highest since records began in 1951 and highest since September 7, 1996 (31.43 feet) during the remains of Hurricane Fran. In terms of flood frequency it fell just above a 25-year event (0.04 annual chance flood). Significant flooding took place with several roads closed, although no structures. A water rescue was reported when a motorist went into the flood waters near Paces. Another water rescue also was successful Friday morning for a motorist trapped in a car in the 4000 block of River Road, possibly from the Dan River.

Charlotte County was included in a Presidential Major Disaster declaration due mainly to the severe flooding associated with Tropical Storm Michael. There was widespread flash flooding across the county with numerous roads closed and damaged. Two people lost their lives after being swept off a bridge into floodwaters. The fatalities occurred after a car stranded on a Mt. Harmony Road bridge around 728 PM local Thursday. The Charlotte County Sheriff's office stated that the vehicle originally had three occupants who were said to be clinging to the bridge railings. A 17-year-old male was able to be rescued, while the two other adults, one male the other female were swept away in the flood waters.

Rainfall of 3 to 5 inches in just a few hours caused flash flooding across parts of Buckingham County. A road was washed out near the intersection of Sycamore creek abd Wood land Church Road. Sharps Creek was flooded across Diana Road washing a vehicle into the stream and some distance downstream before a successful water rescue was carried out. The Slate River near Arvonia (ARVV2) crested at 15.1 feet, above the Minor flood stage of 12 feet.