EF0 tornado, Guilford, Maryland, July 29, 2021

1. EF065 to 85 mphthis tornado

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

2. EF186 to 110 mph

   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

EF0

Date

July 29, 2021

Touchdown

5:07 PM EDT (21:07 UTC)

Lifted

5:08 PM EDT (21:08 UTC)

On the ground

1 minutes

Path length

0.3 miles (0.5 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$50,000

County

Howard County

Touchdown point

39.181, -76.822

Lift-off point

39.182, -76.817

Record number

2107291507-01

4 damage points were recorded along this path by NWS LWX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

• 50 foot section of exterior wall façade removed.
• Large branches snapped and blown in multiple directions. Debris blown to the southeast.

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

Supercell thunderstorms produced large hail, damaging wind and a tornado during the afternoon hours. The hardest hit areas were near Columbia, Maryland, and near Falmouth, Virginia.

A brief EF0 tornado touched down at the Snowden Square shopping mall. Damage was limited to a quarter-mile path, and peak wind gusts were estimated to have been around 70 mph.||Initial tree damage was noted in front of the Goodwill store where two ornamental trees were snapped at their base. Small branch and leaf litter was noted as the tornado passed over the open parking lot towards a BJs store. As the tornado passed over a BJ`s store and tire center, a section of the wall facade, estimated about 50 feet by 20 feet, was removed. The affected wall was on the opposite side from the direction of storm motion. An employee at the tire center noted that nearby shopping carts were lofted and then rapidly blown to the north. The store manager noted the time of the incident from a video taken in the store shortly after it happened. That time matched the time that a tight tornadic circulation with hook echo was noted right over the shopping center by the nearby TBWI terminal doppler weather radar. TBWI|radar had a good view of the event, and was just 10 miles away and sampling only 600 feet off the ground over the shopping center.||Final damage was noted to two more mid-sized trees at the end of Snowden Square Drive. Large branches were snapped off and thrown in multiple directions, north to southeast. Trash and debris was also noted to have been blown to the southeast into an adjacent field. No further damage was noted past this point.

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

8 minutes of warning. NWS LWX issued a tornado warning for this county at 20:59 UTC, 8 minutes before the tornado touched down, in force until 21:19 UTC.

The county was under a tornado watch, issued at 18:25 UTC and running to 23:48 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 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), 62 km away, was scanning. The volume nearest the touchdown began at 21:05 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 2021 tornado in MarylandEvery tornado in Maryland since 1950Warnings in force in Maryland nowThe forecast where you are

36 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.