A vigorous upper level storm system followed a favorable track for Panhandles severe thunderstorms as it crossed southern Nevada and moved east into the Desert Southwest.  A frontal boundary in the area and the storm system led to significant wind shear and instability across the area.  This led to two rounds of severe weather occurred across the Texas Panhandle on the 20th.  A combination of supercell storms and small thunderstorm line segments developed and moved across the northern Texas Panhandles.  These storms produced wind damage, hail up to tennis ball size and flooding through the morning hours.  The storms helped enhanced a cold front positioned across the area causing it to shift south focusing the strongest storms across the southeastern portions of the area for the afternoon.
After a brief lull in activity, an upper level disturbance back to the west of the Panhandles coupled with daytime heating south of a cold front, moderate and an abundant moisture provided a favorable environment for additional supercell thunderstorm development across areas that previously did not see storms earlier in the morning (the southeast TX Panhandle).  With high amounts of instability during the afternoon, very large hail up to 5.5 in diameter was reported along with a tornado southwest of Wellington, TX.  Supercells eventually moved east of the Panhandles  during the evening of the 20th.

Hail in HUTCHINSON, TEXAS
From 20-MAY-19 07:50:00 to 20-MAY-19 07:50:00 (CST-6)
Location: PRINGLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Late report via social media of golf ball hail size.

Hail in MOORE, TEXAS
From 20-MAY-19 12:04:00 to 20-MAY-19 12:04:00 (CST-6)
Location: FOUR WAY
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in HANSFORD, TEXAS
From 20-MAY-19 05:00:00 to 20-MAY-19 05:00:00 (CST-6)
Location: SPEARMAN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Pictures from social media show at least golf ball sized hail, possibly larger, that fell in the Spearman area this morning. Hail lasted for 20 minutes with a gradual decrease in size over time.

Hail in LIPSCOMB, TEXAS
From 20-MAY-19 06:48:00 to 20-MAY-19 06:48:00 (CST-6)
Location: FOLLETT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report of quarter size hail with heavy rain in the area.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:39:00 to 20-MAY-19 14:39:00 (CST-6)
Location: WELLINGTON
Magnitude: 4.00 
Reported by: Broadcast Media

Late report from ABC affiliate of grapefruit size hail.

Hail in RANDALL, TEXAS
From 20-MAY-19 06:58:00 to 20-MAY-19 06:58:00 (CST-6)
Location: AMARILLO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Late report of quarter size hail in the Sleepy Hollow Neighborhood of Amarillo. Time estimated by radar.

Hail in RANDALL, TEXAS
From 20-MAY-19 07:14:00 to 20-MAY-19 07:14:00 (CST-6)
Location: AMARILLO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report for Caprock High School.

Hail in WHEELER, TEXAS
From 20-MAY-19 16:15:00 to 20-MAY-19 16:15:00 (CST-6)
Location: WHEELER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Late report of pea to penny size hail, time estimated from radar.

Thunderstorm Wind in HANSFORD, TEXAS
From 20-MAY-19 05:04:00 to 20-MAY-19 05:04:00 (CST-6)
Location: SPEARMAN
Magnitude: 52.00 EG
Reported by: Broadcast Media

Late report of multiple center pivot sprinklers overturned by thunderstorm winds. Time estimated from radar.

Hail in DONLEY, TEXAS
From 20-MAY-19 14:49:00 to 20-MAY-19 14:49:00 (CST-6)
Location: CLARENDON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Late report of dime to quarter size hail, time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 16:25:00 to 20-MAY-19 16:25:00 (CST-6)
Location: WELLINGTON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DONLEY, TEXAS
From 20-MAY-19 19:17:00 to 20-MAY-19 19:17:00 (CST-6)
Location: HEDLEY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report of quarter size hail, time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:39:00 to 20-MAY-19 14:39:00 (CST-6)
Location: WELLINGTON
Magnitude: 5.50 
Reported by: Social Media

Late report, with picture from Social Media of 5.5 inch hail displayed from local NBC affiliate. Time estimated from radar.

Hail in LIPSCOMB, TEXAS
From 20-MAY-19 06:39:00 to 20-MAY-19 06:39:00 (CST-6)
Location: FOLLETT
Magnitude: 1.50 
Reported by: Social Media

Hail not measured, but received pictures on social media along with reports of at least two broken windows.

Flood in HUTCHINSON, TEXAS
From 20-MAY-19 08:22:00 to 20-MAY-19 08:22:00 (CST-6)
Location: BORGER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Street flooding causing traffic delays in Borger.

Hail in DONLEY, TEXAS
From 20-MAY-19 19:22:00 to 20-MAY-19 19:22:00 (CST-6)
Location: HEDLEY
Magnitude: 2.00 
Reported by: Public

Late report of hail damaging windshield on Texas highway 273.

Hail in HANSFORD, TEXAS
From 20-MAY-19 05:10:00 to 20-MAY-19 05:10:00 (CST-6)
Location: SPEARMAN
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Flood in HUTCHINSON, TEXAS
From 20-MAY-19 08:25:00 to 20-MAY-19 08:25:00 (CST-6)
Location: FRITCH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Street flooding causing traffic delays in Fritch.

Flash Flood in HUTCHINSON, TEXAS
From 20-MAY-19 09:48:00 to 20-MAY-19 09:48:00 (CST-6)
Location: PRINGLE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Flooding in area of Texas Highway 136, with 18 inches, rapidly flowing over roadway.

Hail in OCHILTREE, TEXAS
From 20-MAY-19 06:00:00 to 20-MAY-19 06:00:00 (CST-6)
Location: PERRYTON MUNI ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report. Time estimated by radar.

Hail in LIPSCOMB, TEXAS
From 20-MAY-19 06:19:00 to 20-MAY-19 06:19:00 (CST-6)
Location: LIPSCOMB
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in POTTER, TEXAS
From 20-MAY-19 07:14:00 to 20-MAY-19 07:14:00 (CST-6)
Location: AMARILLO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WHEELER, TEXAS
From 20-MAY-19 14:43:00 to 20-MAY-19 14:43:00 (CST-6)
Location: NEW MOBEETIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Late report of heavy rain and up to quarter size hail, time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:46:00 to 20-MAY-19 14:46:00 (CST-6)
Location: WELLINGTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in POTTER, TEXAS
From 20-MAY-19 07:18:00 to 20-MAY-19 07:18:00 (CST-6)
Location: AMARILLO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Hail in RANDALL, TEXAS
From 20-MAY-19 07:01:00 to 20-MAY-19 07:01:00 (CST-6)
Location: AMARILLO
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in HANSFORD, TEXAS
From 20-MAY-19 10:45:00 to 20-MAY-19 10:45:00 (CST-6)
Location: SPEARMAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Late report of water over roadway requiring rescue of 1 motorist along Highway 15 west of Spearman. Other completely flooded roadways include County Road U and Highway 760 west and northwest of Spearman.

Hail in RANDALL, TEXAS
From 20-MAY-19 07:00:00 to 20-MAY-19 07:00:00 (CST-6)
Location: CANYON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Picture from social media of quarter size hail.

Hail in RANDALL, TEXAS
From 20-MAY-19 07:00:00 to 20-MAY-19 07:00:00 (CST-6)
Location: AMARILLO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in LIPSCOMB, TEXAS
From 20-MAY-19 06:40:00 to 20-MAY-19 06:40:00 (CST-6)
Location: LIPSCOMB
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:50:00 to 20-MAY-19 14:50:00 (CST-6)
Location: WELLINGTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in OLDHAM, TEXAS
From 20-MAY-19 11:33:00 to 20-MAY-19 11:33:00 (CST-6)
Location: BOYS RANCH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail up to the size of quarters (1) reported at Boys Ranch.

Hail in OLDHAM, TEXAS
From 20-MAY-19 11:40:00 to 20-MAY-19 11:40:00 (CST-6)
Location: BOYS RANCH
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report of  quarter size hailstones.

Hail in HUTCHINSON, TEXAS
From 20-MAY-19 08:06:00 to 20-MAY-19 08:06:00 (CST-6)
Location: HUTCHINSON CO ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Late report of hail at one inch.

Hail in HUTCHINSON, TEXAS
From 20-MAY-19 13:08:00 to 20-MAY-19 13:08:00 (CST-6)
Location: STINNETT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Late report of quarter size hail north of Stinnett, TX.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:27:00 to 20-MAY-19 14:27:00 (CST-6)
Location: WELLINGTON
Magnitude: 2.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Reported by a live media broadcast.

Tornado in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:29:00 to 20-MAY-19 14:30:00 (CST-6)
Location: WELLINGTON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

NWS damage survey information suggests that a tornado touchdown occurred at 0329 pm CDT 6 miles southwest of Wellington, lasting only 1 minute. Small tree limbs were broken as a result, with time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:39:00 to 20-MAY-19 14:39:00 (CST-6)
Location: WELLINGTON
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:27:00 to 20-MAY-19 14:27:00 (CST-6)
Location: WELLINGTON
Magnitude: 3.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Late report of teacup size hail, time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:43:00 to 20-MAY-19 14:43:00 (CST-6)
Location: WELLINGTON
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Late report from Facebook of tennis ball size hail, time estimated from radar.

Hail in COLLINGSWORTH, TEXAS
From 20-MAY-19 14:39:00 to 20-MAY-19 14:39:00 (CST-6)
Location: WELLINGTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in RANDALL, TEXAS
From 20-MAY-19 07:03:00 to 20-MAY-19 07:03:00 (CST-6)
Location: TIMBERCREEK CANYON
Magnitude: 1.27 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

University researchers reported 1.27 inch hail, measured by calipers.