EF1 tornado, Alanreed, Texas, May 10, 2017

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 mphthis tornado

   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

EF1

Date

May 10, 2017

Touchdown

4:01 AM CDT (09:01 UTC)

Lifted

4:09 AM CDT (09:09 UTC)

On the ground

8 minutes

Path length

2.6 miles (4.3 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Gray County

Touchdown point

35.200, -100.900

Lift-off point

35.220, -100.860

Record number

1705100301-01

19 damage points were recorded along this path by NWS AMA, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 105 mph.

• srn extent of visible damage path width 180 yards at this point
• nrn edge of visible damage
• nern extent of visible damage
• center pivot irrigation overturned

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

As the day progressed through the Panhandles, an upper level trough over eastern New Mexico was moving further towards the western Panhandles and as a result, upper level dynamics with a SW-NE 250 hPa jet streak was setting up over SE New Mexico and the Texas south Plains as we went into the over night hours into the 10th. This set up good upper level dynamics in-conjunction with a good low level veering SE-SW veering profile advecting moisture into the region. With CAPE between 1000-2000 J/kg and LCL heights around 500m across the central and eastern Panhandles, the dynamics were there for supercells and the possibility of tornadoes. From the evening of the 9th through the very early morning hours of the 10th, several large hail and wind reports were confined mainly to the TX but also a few in the OK Panhandle. Two EF-1 tornadoes also occurred in the TX Panhandle from the same supercell early morning on the 10th.

Tornado started in open field WSW of Lake McClellan, TX in Gray County. Moving NE, the tornado peaked in intensity as it approached and moved parallel to the lake and through the north side of the Lake McClellan campground. Peak damage included numerous large tree branches and several trees uprooted or snapped. A few recreational vehicles in the campground also sustained some damages. The tornado dissipated ENE of Lake McClellan just north of McClellan Creek.

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 severe thunderstorm watch, issued at 04:03 UTC and running to 12:00 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 05:48 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.

Pampa (PPA), 46 km from the path, in the two hours either side.

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

The Amarillo radar (KAMA), 75 km away, was scanning. The volume nearest the touchdown began at 09:01 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 2017 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

13 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.