F2 tornado, Dale City to Yorkshire, Virginia, September 17, 2004

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 mph

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

3. F2113 to 157 mphthis tornado

   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

F2

Date

September 17, 2004

Touchdown

5:26 PM EDT (21:26 UTC)

Path length

4.0 miles (6.4 km)

Path width

250 yards (229 m)

Deaths

0

Injuries

0

Property damage

$1.0 million

County

Prince William County

Touchdown point

38.620, -77.420

Lift-off point

38.580, -77.430

Record number

1755

A tornadic thunderstorm moved through central Prince William County. This is the same storm that produced damage earlier in Stafford County. The initial touchdown in Prince William County was west of Dale City, near Independent Hill and Dumfries Road. The storm snapped or uprooted many large hardwood trees. Some of the trees fell on houses and other structures. The storm lifted and then reformed for the second touchdown in Manassas. Several homes suffered roof and shingle damage. An automobile was moved several feet. Damaged also occurred in Manassas Park and in Yorkshire Village. This tornado continued north into Fairfax County.

A tornado touched down on the east side of the City of Manassas. It produced structural damage and tree damage and then continued on to Manassas Park. The tornado damaged several dwellings before lifting in the Yorkshire Subdivision. This complex track left Manassas City, crossed into Prince William County, then crossed into Manassas Park City, crossing back into Prince William County, then finally crossing into Fairfax County.

A tornado touched down on the east side of the City of Manassas. It produced structural damage and tree damage and then continued on to Manassas Park. The tornado damaged several dwellings before lifting in the Yorkshire Subdivision. This complex track left Manassas City, crossed into Prince William County, then crossed into Manassas Park City, crossing back into Prince William County, then finally crossing into Fairfax County.

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

42 minutes of warning. NWS LWX issued a tornado warning for this county at 20:44 UTC, 42 minutes before the tornado touched down, in force until 21:45 UTC.

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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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.

The Sterling radar (KLWX), 42 km away, was scanning. The volume nearest the touchdown began at 21:26 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2004 tornado in VirginiaEvery tornado in Virginia since 1950Warnings in force in Virginia nowThe forecast where you are

57 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.