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.

Thunderstorm Wind in LOUDOUN, VIRGINIA
From 27-MAY-01 13:34:00 to 27-MAY-01 13:34:00 (EST)
Location: STERLING
Property damage: 20K
Reported by: NWS STORM SURVEY

Large trees were downed between Algonkian Parkway and Countryside Boulevard.

Thunderstorm Wind in FAIRFAX, VIRGINIA
From 27-MAY-01 14:00:00 to 27-MAY-01 14:00:00 (EST)
Location: GREAT FALLS
Property damage: 1K
Reported by: TRAINED SPOTTER

Trees were snapped.

Funnel Cloud in CLARKE, VIRGINIA
From 27-MAY-01 12:35:00 to 27-MAY-01 12:50:00 (EST)
Location: WHITE POST
Reported by: LAW ENFORCEMENT

A police officer followed a storm that repeatedly produced a funnel cloud between White Post and Berryville.

Lightning in SHENANDOAH, VIRGINIA
From 27-MAY-01 12:05:00 to 27-MAY-01 12:05:00 (EST)
Location: STRASBURG
Reported by: EMERGENCY MANAGER

A home was struck by lightning.

Tornado in WARREN, VIRGINIA
From 27-MAY-01 12:25:00 to 27-MAY-01 12:33:00 (EST)
Location: ASHBY
Tornado F-scale: F1
Property damage: 65K
Reported by: NWS STORM SURVEY

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

Tornado in CLARKE, VIRGINIA
From 27-MAY-01 12:33:00 to 27-MAY-01 12:33:00 (EST)
Location: MILLWOOD
Tornado F-scale: F1
Property damage: 5K
Reported by: NWS STORM SURVEY

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

Thunderstorm Wind in SHENANDOAH, VIRGINIA
From 27-MAY-01 12:37:00 to 27-MAY-01 12:37:00 (EST)
Location: ORKNEY SPGS
Property damage: 2K
Reported by: EMERGENCY MANAGER

Trees and power lines were downed.

Hail in CLARKE, VIRGINIA
From 27-MAY-01 12:30:00 to 27-MAY-01 12:35:00 (EST)
Location: DOUBLE TOLLGATE
Magnitude: 1.75 
Property damage: 21K
Reported by: GENERAL PUBLIC

Golfball sized hail damaged roofs and siding, stripped paint, broke light fixtures, and shredded vegetation from Double Tollgate to White Post.

Thunderstorm Wind in LOUDOUN, VIRGINIA
From 27-MAY-01 17:34:00 to 27-MAY-01 17:44:00 (EST)
Location: STERLING
Property damage: 80K
Reported by: NWS STORM SURVEY

Downburst winds estimated between 60 and 80 MPH downed trees and damaged homes in the Countryside development.

Thunderstorm Wind in LOUDOUN, VIRGINIA
From 27-MAY-01 17:40:00 to 27-MAY-01 17:40:00 (EST)
Location: ASHBURN
Property damage: 4K
Reported by: TRAINED SPOTTER

Four trees were downed, a window was blown in, and a tent was damaged.

Hail in LOUDOUN, VIRGINIA
From 27-MAY-01 17:30:00 to 27-MAY-01 17:30:00 (EST)
Location: EAST PORTION
Magnitude: 1.75 
Property damage: 250K
Reported by: TRAINED SPOTTER

Marble to golfball sized hail was reported.