F1 tornado, Ashby to Millwood, Virginia, May 27, 2001

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

F1

Date

May 27, 2001

Touchdown

1:25 PM EDT (17:25 UTC)

Path length

5.5 miles (8.8 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$70,000

Counties

Warren and Clarke counties

Touchdown point

39.000, -78.150

Lift-off point

39.020, -78.030

Record number

807

Two rounds of thunderstorms moved across Northern Virginia on the 27th. The first round crossed the Northern Shenandoah Valley between 1 and 3 PM EDT and produced winds in excess of 55 MPH, dangerous lightning, hail, and a tornado. In Shenandoah County, a home in Strasburg was struck by lightning. Marble sized hail was reported in Tom's Brook. Trees and power lines were downed by high wind in Orkney Springs. In Warren County, an F1 tornado touched down around 1 mile southwest of Ashby, just south of Route 639. The tornado moved east-northeast and crossed Route 639 just east of Ashby. Shortly after, it crossed Route 658 just south of White Oak Level and moved into Clarke County at Milldale Road (Route 624). Before exiting the county, the tornado struck three farms just east of Ashby. It tore the tin roof off a barn and threw it 100 yards. A farmhouse suffered a projectile hole and minor damage to trim and a window. The tornado also damaged a silo, several sheds, and small outbuildings. In addition, numerous trees were uprooted and snapped along the tornado's 4 mile long and 100 yard wide path. The tornado remained on the ground for another mile after it crossed into Clarke County at Milldale Road (Route 624), about 3 miles southeast of Stone Bridge. Several trees were downed on the roadway at this location. The tornado traveled to the northeast through woodlands, then dissipated about 5 miles east of Stone Bridge. In addition, a funnel cloud was spotted by a police officer over White Post, north of the tornadic storm. The officer followed the storm that produced the funnel cloud from White Post to Berryville and saw the funnel drop down several times, but never touch the ground. The only damage reported from this storm was from large amounts of golfball sized hail that accumulated up to 6 inches in depth between Double Tollgate and White Post. The large hail damaged an asphalt roof, a flat membrane roof, and light fixtures. It was also responsible for chipping paint off a home and stripping leaves off vegetation. In Loudoun County, a storm downed several large trees near the intersection of Algonkian Parkway and Countryside Boulevard west of Sterling in the Cascades subdivision.The second round of storms moved through the western suburbs of Washington D.C. between 6 and 7 PM EDT and produced winds as high as 80 MPH, large hail, and heavy downpours. In Loudoun County, a strong downburst of wind estimated between 60 and 80 MPH crashed down onto the Countryside subdivision west of Sterling. The strongest winds hit the Foxfield section near where it backs up to the Broad Run Farms subdivision. Several townhouses had shingles peeled off their roofs and roof vents were bent upward or torn off. About a dozen trees were uprooted and others were snapped. Just north of this area on McPhereson Circle, several other homes had damage to siding and gutters. Another area of damage was near the intersection of Algonkian Parkway and Countryside Boulevard. This same area was hit by damaging wind during the first round of storms. Several more large trees were snapped and a significant carpet of leaf debris was left on the ground and blown into fencing and against housing. Another small area of wind damage was reported in Ashburn Farm where a tree was downed, a tent was damaged, and a window was blown in. In addition to high winds, the eastern portion of Loudoun County was pelted by large quantities of hail. In Countryside, hail as large as golfballs punctures the rear window of a soft topped vehicle and shredded leaves off vegetation. The hail covered the ground up to 1 inch deep and nickel sized hail could still be found on the ground a day and a half after the storm. Many homes in the Countryside, Cascades, and the Sugarland Run subdivisions experienced hail damage to roofs and siding. Damage to homes in the path of the largest hailstones was estimated at $5000. Quarter sized hail was reported in Ashburn. Marble to quarter sized hail fell in Sterling. Pea sized hail was reported in Leesburg. In Fairfax County, trees were snapped by high winds in Great Falls.

A tornado damaged farms and trees before moving into Clarke County.

A tornado that came from Warren County downed trees across Route 624 (Millville Rd).

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Slight Risk. The outlook in force was issued at 17:13 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Winchester Regional (OKV), 16 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Sterling radar (KLWX), 52 km away, was scanning. The volume nearest the touchdown began at 17:23 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

The live radar over the trackEvery 2001 tornado in VirginiaEvery tornado in Virginia since 1950Warnings in force in Virginia nowThe forecast where you are

11 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.