Tornadoes · United States · Alabama · 2006

F0 tornado, Limestone County, Alabama, May 9, 2006

This F0 tornado ran 5.0 miles across Limestone County on May 9, 2006, touching down at 5:00 PM CDT and reaching 60 yards wide. It killed nobody.

The rating scale

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

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

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

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F0
Date
May 9, 2006
Touchdown
5:00 PM CDT (22:00 UTC)
Path length
5.0 miles (8.0 km)
Path width
60 yards (55 m)
Deaths
0
Injuries
0
County
Limestone County
Touchdown point
34.900, -87.120
Lift-off point
34.900, -87.020
Record number
500

The warnings

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.

The county was under a severe thunderstorm watch, issued at 21:50 UTC and running to 23:08 UTC.

Issued (UTC)ExpiredProductOffice
21:38 UTC22:09 UTCSevere Thunderstorm WarningHUN
21:50 UTC23:08 UTCSevere Thunderstorm WatchHUN
22:02 UTC22:30 UTCTornado WarningHUN

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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:06 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.

Nashville Metro, TN (KBNA), 12:00Z

10.0 hours before the tornado, 143 km from the path. May 9, 2006.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2006-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -70401, lifted condensation level 810 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 2006-05-09The 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 80 square meters per square second, 0 to 6 km bulk shear 34 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
0 J/kg
Mixed-layer CIN
-70401 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
810 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.4 K/km

Open this sounding in Storm Lab

Nashville Metro, TN (KBNA), 00:00Z

2.0 hours after it, 143 km from the path. May 10, 2006.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2006-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -76312, lifted condensation level 1489 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Nashville Metro, TN at 00:00Z on 2006-05-10The 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 140 square meters per square second, 0 to 6 km bulk shear 39 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
0 J/kg
Mixed-layer CIN
-76312 J/kg
Surface CAPE
53 J/kg
Mixed-layer LCL
1489 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
309 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

The radar

The Northeast Alabama radar (KHTX), 90 km away, was scanning. The volume nearest the touchdown began at 21:58 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
21:39 UTCTSTM WND DMG3 Wsw LexingtonLauderdale, ALFOUR TREES DOWN NEAR THE INTERSECTION OF HWY 64 AND 43. TREES BLOCKING THE ROAD ON HWY 64. RELAYED BY WHNT-TV.
21:40 UTCTSTM WND DMGElginLauderdale, ALHOUSE WITH ROOF DAMAGE ALONG HIGHWAY 101.
21:40 UTCTSTM WND DMGUnderwood-PetersvilleLauderdale, ALLARGE TREE DOWN.
21:44 UTCTSTM WND DMGLeightonColbert, ALBARN BLOWN DOWN ALONG OLD HWY 20.
21:44 UTCTSTM WND DMGTuscumbiaColbert, ALNUMEROUS TREES DOWN COUNTYWIDE.
22:00 UTCTSTM WND DMGCairoLimestone, ALSEVERAL TREES DOWN ACROSS THE CAIRO AND SALEM COMMUNITIES. TIME ESTIMATED.
22:07 UTCTSTM WND DMG2 Nw AthensLimestone, ALSEVERAL TREES DOWN ALONG EASTER FERRY AND LUCAS FERRY ROADS NEAR ATHENS.
22:20 UTCTSTM WND DMGCourtlandLawrence, ALTHREE TREES DOWN NEAR CR 150...FELL ON A CAR AND PULLED A POWER LINE DOWN.
22:29 UTCFUNNEL CLOUDHarvestMadison, ALPOSSIBLE FUNNEL OR WALL CLOUD NEAR THE INTERSECTION OF JEFF RD. AND HWY 53.
22:30 UTCTSTM WND DMGHarvestMadison, ALTWO TREES DOWN ALONG WALL TRIANA HWY...ONE ACROSS THE ROAD NEAR THE HARVEST RD INTERSECTION. TIME ESTIMATED.
22:33 UTCFUNNEL CLOUDHazel GreenMadison, ALREPORTED NEAR BROOKS CHAPEL RD. AND IN COMMUNITY OF BOBO. RELAYED BY MADISON COUNTY EMA.
22:40 UTCTSTM WND DMGHuntsvilleMadison, ALPOWER LINES DOWNED ALONG PULASKI PIKE NORTH OF SPARKMAN DR.
22:45 UTCTSTM WND DMGHazel GreenMadison, ALPOWER LINE DOWNED AND ON FIRE ALONG SHILOH ROAD. TIME ESTIMATED.

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

This ground now

The live radar over the trackEvery 2006 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

The other tornadoes of May 9, 2006

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 95:05 PM CDTF0Limestone, AL0.130$20,000
May 96:59 PM CDTF0Coal, OK0.220
May 98:01 PM CDTF0Atoka, OK0.630
May 98:04 PM CDTF0Atoka, OK0.220
May 99:10 PM CDTF0Grayson, TX0.125
May 99:30 PM CDTF2Childress, TX1.51751$5.7 million
May 910:26 PM CDTF0Collin, TX0.125
May 910:33 PM CDTF0Collin, TX0.440$30,000
May 910:37 PM CDTF3Collin, TX9.3300310$1.5 million

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.