EF1 tornado, Browns Store to Lilian, Virginia, August 4, 2020

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

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

3. EF2111 to 135 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. EF3136 to 165 mph

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

5. EF4166 to 200 mph

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

6. EF5over 200 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

EF1

Date

August 4, 2020

Touchdown

6:06 AM EDT (10:06 UTC)

Lifted

6:09 AM EDT (10:09 UTC)

On the ground

3 minutes

Path length

2.2 miles (3.5 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$626,000

County

Northumberland County

Touchdown point

37.814, -76.277

Lift-off point

37.844, -76.287

Record number

2008040406-01

1 damage points were recorded along this path by NWS AKQ, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 69 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The center of Tropical Storm Isaias tracked north just inland of the Middle Atlantic Coast from late Monday night, August 3rd through Tuesday morning, August 4th. Outer bands north and east of the Tropical Storm produced seven tornadoes across portions of eastern and southeast Virginia.

The tornado, as an EF1, tracked from Lancaster county into Northumberland County near Browns Store Road before lifting just north of Light Street. Mostly trees were snapped or downed in this area.

A damage survey conducted by the NWS Wakefield office found a path of storm damage consistent with an EF1 tornado. The tornado moved onshore from the Chesapeake Bay in the town of Fleeton, crossing Fleeton Road where several houses experienced roof and siding damage. In addition, trees were snapped and uprooted. The tornado then crossed over the Wicomico River and then moved back onshore near Timbs Road where trees were uprooted and snapped, and a few houses experienced roof and siding damage. The tornado then moved northward to near Buzzards Point Road, destroying a canopy, before lifting.

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

24 minutes of warning. NWS AKQ issued a tornado warning for this county at 09:42 UTC, 24 minutes before the tornado touched down, in force until 10:15 UTC.

The county was under a tornado watch, issued at 06:28 UTC and running to 12:31 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 05:53 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 Norfolk radar (KAKQ), 114 km away, was scanning. The volume nearest the touchdown began at 10:03 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 2020 tornado in VirginiaEvery tornado in Virginia since 1950Warnings in force in Virginia nowThe forecast where you are

30 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.