EF0 tornado, Knapp to Winston, Texas, April 23, 2008

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

April 23, 2008

Touchdown

2:34 PM CDT (19:34 UTC)

Lifted

2:42 PM CDT (19:42 UTC)

On the ground

8 minutes

Path length

5.1 miles (8.1 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Scurry County

Touchdown point

32.685, -101.082

Lift-off point

32.692, -100.995

Record number

0804231334-01

Strong southeast winds were established during the proceeding night bringing abundant low level moisture to the region. By morning, a surface low located just west of Wink had an associated warm front extending northeastward into Oklahoma. Based on the NWS Midland morning upper air balloon sounding, a very unstable airmass was in place. The potential for large hail, damaging winds, and tornadoes was realized across the Permain Basin, Western Low Rolling plains, and Trans Pecos Regions as an upper level disturbance interacted with atmospheric instability currently in place across the area. In addition, strong low and mid level wind shear resulted in well organized and long lived thunderstorms. The strongest storms, which produced hail up to softball size and multiple tornadoes, developed as outflow boundaries from thunderstorms north of the area converged with the warm front that became stationary during the afternoon. The severe weather events began by mid morning and lasted into the early evening hours.

The NWS survey conducted by WFO Midland did confirm power pole damaged approximately 2.8 miles south of the Union community along Farm to Market Road 1609. This tornado damage was indicative of EF0 intensity. Based on radar imagery and storm speed, primary indications are that the tornado path extended to the west of Farm to Market Road 1609 for approximately 4-6 miles. The width of the tornado is estimated at 50 yards.

A tornado developed near the city of Winston. In Towle Park, large trees were uprooted. At the nearby High School, a 20x40 storage building adjacent to the school was rolled and destroyed. The new football scoreboard was also demolished. The uprooting of well established trees in Towle Park and the damage observed to the storage building at Snyder High School are indicative of EF1 tornado damage. EF1 damage was also observed along Voss Lane near the end of the Snyder tornado life cycle, where metal farm buildings sustained significant damage. Wind speeds for this tornado are estimated at 90-100 mph, which is believed to have stayed on the ground for approximately 3.5 minutes, travelling approximately 1.75 miles. The tornado width is estimated at 100 yards.|||A 59 mph wind gust from the north was measured at Winston Field at 3:05 pm. A 69 mph wind gust from the northwest was measured at the Texas Tech Mesonet station located 3 miles east of Snyder at 3:10 pm. In both cases, these wind gusts occurred after the tornadic supercell thunderstorm had already moved east of the area.

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. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 15:10 UTC and running to 20:25 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 Moderate Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 17:08 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.

Snyder (SNK), 8 km from the path, in the two hours either side.

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

The Lubbock radar (KLBB), 129 km away, was scanning. The volume nearest the touchdown began at 19:34 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 2008 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

19 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.