EF0 tornado, Hayden, Alabama, March 31, 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

March 31, 2021

Touchdown

8:15 AM CDT (13:15 UTC)

Lifted

8:16 AM CDT (13:16 UTC)

On the ground

1 minutes

Path length

0.2 miles (0.3 km)

Path width

65 yards (59 m)

Deaths

0

Injuries

0

County

Blount County

Touchdown point

33.891, -86.738

Lift-off point

33.893, -86.735

Record number

2103310715-01

9 damage points were recorded along this path by NWS BMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 80 mph.

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

A warm front moved pushed northward into north Central Alabama late on March 30th and into the early morning hours on March 31st. A low pressure area developed along the warm front and tracked from west to east across northern Alabama. This feature pooled instability just south of the front and added just enough shear for some rotating and organized storms. Subsequently, three weak and short-lived tornadoes developed. Due to the strong southerly winds and lift near the front, heavy rainfall was observed across northern Alabama. Widespread amounts of 1 to 3 inches of rain were observed with localized amounts of 5 to 6 inches west of I-65. These amounts produced flash flooding in several locations where roads were washed out and or became impassable. Additionally, many local creeks and streams flooded and this eventually lead to river and lake flooding.

National Weather Service meteorologists surveyed damage in southeast Blount County and determined that it was consistent with an EF0 tornado, with maximum winds near 80 mph.||The tornado touched down just west of Armstrong Loop and initially snapped several large branches and uprooted several large pine trees in the front yard of a residence. The tornado traveled into a wooded area nearly parallel to Russell Drive where a few more softwood trees were uprooted and large branches snapped. The tornado lifted at the end of Russell Drive just before crossing Hayes Creek.

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.

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 12:51 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.

Birmingham Municipal (BHM), 36 km from the path, in the two hours either side.

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

The Birmingham radar (KBMX), 80 km away, was scanning. The volume nearest the touchdown began at 13:17 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 AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

4 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.