Tornadoes · United States · Alabama · 2010

EF0 tornado, Blountsville, Alabama, April 8, 2010

This EF0 tornado ran 0.2 miles across Blount County on April 8, 2010, touching down at 4:42 AM CDT and reaching 50 yards wide. It killed nobody, and did $15,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF0
Date
April 8, 2010
Touchdown
4:42 AM CDT (09:42 UTC)
Lifted
4:43 AM CDT (09:43 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.3 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$15,000
County
Blount County
Touchdown point
34.088, -86.594
Lift-off point
34.091, -86.592
Record number
1004080342-01

What the Weather Service recorded

A cold front pushing through the area caused numerous showers and thunderstorms across central Alabama. One storm produced a weak tornado, and another an isolated area of wind damage.

The short-lived tornado touched down on the northernmost ball field in Blountsville Park, where it ripped the tin roofing off the dugouts and carried them to a tree line approximately 300 to 400 yards down the path. It then continued to the north-northeast for less than a quater mile and crossed Park Drive, where it damaged a portion of the roof of a house. One large oak tree with a poor root system was also uprooted.

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

The warnings

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 forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 05:47 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 air that afternoon

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, AL (KBMX), 00:00Z

9.7 hours before the tornado, 103 km from the path. April 8, 2010.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2010-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 136 joules per kilogram, CIN -133, lifted condensation level 1553 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Birmingham, AL at 00:00Z on 2010-04-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 50 square meters per square second, 0 to 6 km bulk shear 31 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
136 J/kg
Mixed-layer CIN
-133 J/kg
Surface CAPE
102 J/kg
Mixed-layer LCL
1553 m above ground
0-6 km bulk shear
31 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

Birmingham, AL (KBMX), 12:00Z

2.3 hours after it, 103 km from the path. April 8, 2010.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2010-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 247 joules per kilogram, CIN -7, lifted condensation level 447 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Birmingham, AL at 12:00Z on 2010-04-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 213 square meters per square second, 0 to 6 km bulk shear 57 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
247 J/kg
Mixed-layer CIN
-7 J/kg
Surface CAPE
8 J/kg
Mixed-layer LCL
447 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
36 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
232 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

The radar

The Birmingham radar (KBMX), 103 km away, was scanning. The volume nearest the touchdown began at 09:40 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
09:42 UTCTORNADO 01 Wsw BlountsvilleBlount, ALA NWS SURVEY TEAM HAS CONFIRMED THE ROOF DAMAGE TO A WELL BUILT HOME WAS CAUSED BY A BRIEF TOUCHDOWN OF AN EF-0 TORNADO WITH WINDS OF APPROXIMATELY 80 MPH. THE PATH LENGTH WAS 0.2 MILES WITH A MAXIMUM WIDTH OF 50 YARDS.
09:44 UTCTSTM WND DMGBlountsvilleBlount, ALPARTIAL ROOF DAMAGE TO A RESIDENCE. POSSIBLE TORNADO.
11:28 UTCTSTM WND DMG3 Nw GadsdenEtowah, ALREPORTS OF LOTS OF TREES DOWN IN THE ATTALLA/GADSDEN AREA. STATE TROOPERS HAVE ALSO REPORTED TREES DOWN BETWEEN MILE MARKER 183 AND 188 ON INTERSTATE 59. THE INTERSTATE HAS BEEN CLOSED IN BOTH DIRECTIONS.
11:28 UTCTSTM WND DMGAttallaEtowah, ALLOTS OF POWER LINES DOWN ON US HIGHWAY 11 IN ATTALLA.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2010 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

The other tornadoes of April 8, 2010

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 87:15 AM CDTEF0Washington, AL0.1100
April 812:10 PM CDTEF0Coffee, AL3.075
April 82:38 PM EDTEF0Gadsden, FL1.075
April 84:50 PM EDTEF1Morgan, GA1.850$218,000
April 85:01 PM EDTEF0Oconee, SC0.730$5,000
April 85:26 PM EDTEF1Anderson, SC2.075$100,000
April 811:11 PM EDTEF0Beaufort, SC0.120$40,000

What this means

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.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.