An upper level low in the southwestern US combined with ample instability across West Texas to create numerous severe thunderstorms with one long lived supercell producing a tornado. There were two areas of thunderstorm development late in the afternoon of the 16th. The first was in the extreme southeastern Texas Panhandle along a lingering outflow boundary located from northwest Texas into the central Panhandle near Amarillo. The second area was along a dryline in the western South Plains. The lone thunderstorm that developed along the dryline to survive past sunset became a long lived supercell which tracked from Lamb County into Crosby County over several hours. Shortly after this supercell developed in western Lamb County, it produced a brief tornado between Earth and Amherst photographed by several storm chasers. The tornado remained over open land and did not cause any known damage. This supercell would go on to nearly dissipate while over western Hale County. However, it regenerated over central Hale County and would go on to produce a long hail swath of up to three inch diameter hail from central Hale County to Petersburg (Hale County). Meanwhile, widespread thunderstorms developed in the extreme southern Texas Panhandle into the Rolling Plains on a cold pool that moved south out of the central Texas Panhandle. These thunderstorms would produce sporadic severe wind gusts and severe hail.

Hail in SWISHER, TEXAS
From 16-MAY-21 18:40:00 to 16-MAY-21 18:40:00 (CST-6)
Location: HAPPY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A report of quarter size hail was received from the public just south of Happy.

Thunderstorm Wind in HALL, TEXAS
From 16-MAY-21 20:07:00 to 16-MAY-21 20:28:00 (CST-6)
Location: LESLEY
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A Texas Tech University West Texas mesonet site near Lesley measured severe wind gusts from 2007 CST through 2028 CST. A maximum wind gust of 73 mph was reported at 2028 CST.

Hail in COTTLE, TEXAS
From 16-MAY-21 18:30:00 to 16-MAY-21 18:30:00 (CST-6)
Location: CEE VEE
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A report was received via social media of half dollar size hail east of Cee Vee.

Tornado in LAMB, TEXAS
From 16-MAY-21 18:40:00 to 16-MAY-21 18:43:00 (CST-6)
Location: SUDAN
Tornado F-scale: EFU
Reported by: Trained Spotter

Numerous storm chasers photographed a brief tornado in an open field about seven miles south of Earth. No known damaged occurred so a rating of EF-unknown was assigned to this tornado.

Hail in HALE, TEXAS
From 16-MAY-21 21:31:00 to 16-MAY-21 22:17:00 (CST-6)
Location: HALE CENTER
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

An intense supercell thunderstorm, which previously produced a tornado earlier in the evening, produced a large hail swath from approximately six miles south of Hale Center to Petersburg. Numerous reports of hail were received along this path length. Hail sizes ranged from quarter size at the initial report near the intersection of Interstate 27 and Farm to Market Road 37 at 2131 CST to three inches in diameter about five miles northwest of Petersburg at 2157 CST.

Hail in LAMB, TEXAS
From 16-MAY-21 18:29:00 to 16-MAY-21 18:29:00 (CST-6)
Location: EARTH
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A storm spotter reported hail up to ping pong size south of Earth on Farm to Market Road 1055. No damage was reported.

Hail in CHILDRESS, TEXAS
From 16-MAY-21 16:33:00 to 16-MAY-21 16:49:00 (CST-6)
Location: KIRKLAND
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Reports of hail up to ping pong size from law enforcement and an NWS cooperative weather observer in Kirkland. No damage was reported.