Isolated dryline thunderstorms developed on the evening of May 16, well in advance of an approaching upper level low.  These storms produced an EF-0 tornado on the north side of Anson, and large hail and damaging winds in Fisher and Haskell Counties.  An approaching upper low from New Mexico interacted with a warm front on May 17, and produced a long track EF2 tornado across northern Sterling County along with several severe weather reports.  Many storm chasers videotaped this tornado as it tracked across the wind farms.  Heavy rain resulted in some flash flooding in Fisher County on the night of May 18 and in Irion County on the afternoon of May 19.

Tornado in HASKELL, TEXAS
From 16-MAY-21 21:46:00 to 16-MAY-21 21:47:00 (CST-6)
Location: STAMFORD
Tornado F-scale: EF0
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

This EF-0 tornado with peak winds estimated at 85 mph began just west of U.S. Highway 277 where it damaged a roof of a home and broke many smaller to medium size Mesquite tree branches.  It crossed U.S. Highway 277, broke more tree limbs and struck an auto and body shop.  The tornado lifted a small steel metal building at the auto and body shop and threw it 75 yards.  It broke tree branches and damaged the roof of a nearby building.  The tornado also caused debris to penetrate a nearby metal building, and it damaged a nearby porch.

Tornado in STERLING, TEXAS
From 17-MAY-21 18:11:00 to 17-MAY-21 18:47:00 (CST-6)
Location: STERLING CITY
Tornado F-scale: EF2
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A NWS Storm Survey was conducted for this tornado that was videotaped by many storm chasers throughout it's track across northern Sterling County.  We found many snapped Mesquite tree trunks and plenty of tree limb damage.  The tornado moved large wind turbine propellers at two different locations, and it snapped 16 power poles across two ranches.  The tornado caused a wind mill stand to bend over.  A nearby crane located about a mile south of the tornado track or in the rear flank downdraft, measured a wind speed of 109 mph.  The twister destroyed a camper.
The collective videotapes on social media from the many storm chasers, showed the tornado starting out as a multi-vortex tornado in the northwest part of Sterling County around 711 PM CDT, transitioning to a large cone near the wind farms, and then becoming rain wrapped as it struck the gas plant at around 747 PM CDT. As the tornado struck a gas plant on State Highway 163, it slung a large dumpster about 300 yards into a nearby pasture, snapped a telephone pole and threw a large Conix container about 50 feet.  It also bent one of the towers on the plant.
Many thanks to the Sterling County Sheriff's Department, the Stewart Ranch, National Weather Service Midland, other ranchers and all of the storm chasers for their excellent assistance.

Thunderstorm Wind in HASKELL, TEXAS
From 16-MAY-21 21:23:00 to 16-MAY-21 21:23:00 (CST-6)
Location: O BRIEN
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Damaging thunderstorm winds damaged an outbuilding and blew down a grain house on the south side of O'Brien near State Highway 6.

Thunderstorm Wind in COLEMAN, TEXAS
From 17-MAY-21 08:08:00 to 17-MAY-21 08:08:00 (CST-6)
Location: COLEMAN
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Large tree limbs and power lines were blown down by damaging thunderstorm winds across the central and south central part of Coleman.

Hail in STERLING, TEXAS
From 17-MAY-21 18:40:00 to 17-MAY-21 18:40:00 (CST-6)
Location: STERLING CITY
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A storm chaser reported baseball size hail.

Hail in NOLAN, TEXAS
From 17-MAY-21 18:57:00 to 17-MAY-21 18:57:00 (CST-6)
Location: SWEETWATER
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported this 1.25 inch hail report on the north side of Sweetwater using the Mping App.

Hail in FISHER, TEXAS
From 16-MAY-21 20:08:00 to 16-MAY-21 20:08:00 (CST-6)
Location: CLAYTONVILLE
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter measured this hail stone at 2.2 inches.

Hail in TAYLOR, TEXAS
From 17-MAY-21 20:21:00 to 17-MAY-21 20:21:00 (CST-6)
Location: ABILENE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A member of the public on social media measured 1 inch hail on the northeast side of Abilene.

Hail in TOM GREEN, TEXAS
From 18-MAY-21 01:15:00 to 18-MAY-21 01:15:00 (CST-6)
Location: VANCOURT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in COKE, TEXAS
From 17-MAY-21 20:37:00 to 17-MAY-21 20:37:00 (CST-6)
Location: BRONTE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Flash Flood in FISHER, TEXAS
From 18-MAY-21 04:58:00 to 18-MAY-21 04:58:00 (CST-6)
Location: CELOTEX
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The Fisher County Sheriff's Office reported flooding for several miles along FM 57, between Hamlin and McCaulley.

Flash Flood in IRION, TEXAS
From 19-MAY-21 18:30:00 to 19-MAY-21 18:30:00 (CST-6)
Location: BARNHART
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The Irion County Sheriff's Office reported numerous locations along FM 163 north of Barnhart under water with debris floating in the roadway.  Flooding was also reported on CR 401 and CR 131.