EF1 tornado, Ashland to Greenville, Delaware, August 7, 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 7, 2020

Touchdown

5:40 PM EDT (21:40 UTC)

Lifted

5:51 PM EDT (21:51 UTC)

On the ground

11 minutes

Path length

4.2 miles (6.7 km)

Path width

450 yards (411 m)

Deaths

0

Injuries

0

County

New Castle County

Touchdown point

39.797, -75.658

Lift-off point

39.790, -75.580

Record number

2008071540-01

24 damage points were recorded along this path by NWS PHI, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 107 mph.

• Trunk snapped, fell onto the roof of a house.
• Several trees uprooted. Collatoral damage to wires and poles.
• Large tree uprooted causing major damage to a residence.
• At least 5 trees uprooted or snapped on a single property.

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

An impulse riding along a west to east boundary stalled near the Mason-Dixon line produced severe thunderstorms and heavy rain across sections of northern Delaware from late afternoon through the evening hours on August 7th. Strong winds knocked down trees, and torrential downpours on ground already saturated from the remnants of Hurricane Isaias produced flash flooding on many roadways and small streams in the area.

A tornado touched down around 5:40 PM on August 7th close to the |Ashland Nature Center of the Delaware Nature Society or just east |of the intersection of Brackenville Road and Barley Mill Road |where some tree damage occurred. The tornado continued east |southeast to the Swallow Hill area where there were multiple trees|down across Pyles Ford Road. Trees were snapped at the trunk, |with one tree falling on the roof of a house. Pyles Ford Road was |closed due to the amount of tree damage across the road. This wind|damage was estimated to be 105 mph, equivalent to an EF1 on the |Enhanced Fujita Scale. ||The tornado continued in an easterly direction where substantial |tree damage occurred just north of Valley Garden Park where over |20 trees were uprooted or damaged. Campbell Road was also closed |due to the multiple trees down. More damage occurred along Kennett|Pike between Kirk Road and the entrance of Wilmington Country |Club where several trees were uprooted along with large tree limbs|knocked down. The tornado continued through the Wilmington |Country Club where approximately 200 trees were damaged. A noted |convergent pattern in the debris was observed in the tree damage |across the Wilmington Country Club. The tornado then continued |eastward before lifting prior to reaching Rockland, Delaware. No |further damage was noted in the DuPont Country Club or on Concord |Pike.

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 Marginal Risk. The outlook in force was issued at 19:34 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.

Wilmington Airport (ILG), 13 km from the path, in the two hours either side.

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

The Philadelphia radar (KDIX), 105 km away, was scanning. The volume nearest the touchdown began at 21:41 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 DelawareEvery tornado in Delaware since 1950Warnings in force in Delaware nowThe forecast where you are

2 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.