EF2 tornado, Silverhill, Alabama, March 9, 2011

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 mph

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

3. EF2111 to 135 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. 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

EF2

Date

March 9, 2011

Touchdown

9:17 AM CST (15:17 UTC)

Lifted

9:21 AM CST (15:21 UTC)

On the ground

4 minutes

Path length

2.0 miles (3.3 km)

Path width

350 yards (320 m)

Deaths

0

Injuries

0

County

Baldwin County

Touchdown point

30.534, -87.761

Lift-off point

30.557, -87.739

Record number

1103090917-01

10 damage points were recorded along this path by NWS MOB, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU. The highest wind the damage implies is 130 mph.

• Also a few trees downed in the vicinity of the damage indicator.
• Large town meeting hall shifted several feet off of its foundation with damage to exterior walls and roof. Also nearby, a well built workshop building lost entire roof and some walls. Also at this location several large pine trees snapped mid-trunk.
• Entire roof of home was blown off. Roof not attached with hurricane clips with connections straight nailed.
• Truck was being backed out of post office parking lot...was picked up by tornado and flipped into grass area in front of post office.

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

A powerful cold front brought widespread severe thunderstorms to southwest Alabama. These thunderstorms produced many reports of large hail...damaging winds and tornadoes. The thunderstorms also produced heavy rain which caused flash flooding.

The tornado first touched down on West Boulevard just south of South Boulevard in Silverhill. At this location two homes suffered roof damage with some windows blown out. The tornado then tracked toward the northeast quickly widening and reaching EF-2 intensity on the Enhanced Fujita Tornado Scale as it moved just south of South Avenue west of County Road 55. Maximum winds were between 111 miles per hour and 135 miles per hour. Several homes were destroyed or severely damaged, and a utility trailer was thrown nearly 100 yards. A pickup truck that was backing out of the U.S. Post Office was tossed 40 yards and flipped, with minor injuries to the driver. The tornado continue northeast crossing Highway 104, doing major damage to several homes, businesses and structures. The tornado lifted near County Road 52 just east of Hill Road.

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

50 minutes of warning. NWS MOB issued a tornado warning for this county at 14:27 UTC, 50 minutes before the tornado touched down, in force until 15:30 UTC.

The county was under a tornado watch, issued at 13:26 UTC and running to 18:22 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 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 12:38 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 Mobile radar (KMOB), 49 km away, was scanning. The volume nearest the touchdown began at 15:16 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 2011 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

14 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.