F3 tornado, Anna to Pilot Grove, Texas, May 9, 2006

1. F040 to 72 mph

   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 mphthis tornado

   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.

Rating

F3

Date

May 9, 2006

Touchdown

10:37 PM CDT (03:37 UTC)

Path length

9.3 miles (15.0 km)

Path width

300 yards (274 m)

Deaths

3

Injuries

10

Property damage

$1.5 million

Counties

Collin and Grayson counties

Touchdown point

33.370, -96.520

Lift-off point

33.450, -96.400

Record number

509

A damage survey conducted by the National Weather Service in Fort Worth found that a significant tornado developed approximately three miles east-northeast of Anna. A house was unroofed and another damaged just east of Collin County Road 477. Trees and power lines were also downed. A roof was damaged along FM 2862 west of Collin County Road 480. The tornado ranged from an F1 to an F2 on the Fujita Tornado Intensity Scale during this part of its lifetime. The tornado then turned on a slightly more northerly track.The tornado reached its maximum intensity of F3 as it crossed FM 3133 just north of the Westminster community. Vegetation west of FM 3133 was scoured. Two homes were heavily damaged south of Collin County Road 531. A mobile home and several permanent structures suffered heavy damage along Brangus and Black Roads, near the Collin-Grayson County line. These were the locations of the fatalities. Several other people suffered injuries and were transported to hospitals. Numerous livestock were killed. The affected parts of Collin County were declared disaster areas.The tornado continued on its destructive path as it crossed into Grayson County.

A significant tornado which formed in northern Collin County continued into southeastern Grayson County. A damage survey conducted by the National Weather Service in Fort Worth found that the tornado remained strong F3 as it crossed into Grayson County. A fatality occurred on Black Road, just over the border into Grayson County, where permanent homes suffered heavy damage. Numerous trees were snapped or uprooted along Yellow Bridge Road, Durham Road, and Red Moore Road. The tornado damaged outbuildings, rolled over a mobile home, and caused at least minor damage to structures in the area. The tornado, which had briefly weakened to an F1, strengthened again and caused F2 damage as it approached Gordon Road southeast of the Pilot Grove community. At least two additional homes were heavily damaged. The tornado crossed FM 121 and damaged a shed along Bethel Canyon Road, just west of Highway 160. The tornado crossed Highway 160, weakened to an F0, and dissipated approximately three miles south of Whitewright just before 11 PM. In addition to the fatality, several people suffered injuries and were transported to the hospital.

The deaths

3 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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

29 minutes of warning. NWS FWD issued a tornado warning for this county at 03:08 UTC, 29 minutes before the tornado touched down, in force until 04:00 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 01:07 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.

Mc Kinney (TKI), 28 km from the path, in the two hours either side.

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

The Dallas/Ft Worth radar (KFWS), 122 km away, was scanning. The volume nearest the touchdown began at 03:36 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 2006 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

9 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.