A positive tilted upper level trough digging into southern Nevada developed a 80-100 kt jet downstream of its axis. In-conjunction with 700-500 hPa perturbations in the mean flow along with a surface dryline, the ingredients were set for multi cellular thunderstorm develop along a uniform deep uni-directional flow. Other surface features included good theta-e advection along with surface winds advecting moisture east of the dryline. Clusters of supercells then developed in the afternoon hours on the 13th across the eastern panhandles given SBCAPE of 1000-2500 J/Kg. Low to moderate effective shear of around 30 kts did not give these supercells their discrete characteristics and instead developed along a loose line from southwest to northeast along the dryline. However, severe wind gusts along with hail up to the size of baseball size were still reported. Thunderstorms then moved east into western Oklahoma going into the evening hours.

Hail in DONLEY, TEXAS
From 13-MAY-18 16:21:00 to 13-MAY-18 16:21:00 (CST-6)
Location: CLARENDON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in ROBERTS, TEXAS
From 13-MAY-18 16:25:00 to 13-MAY-18 16:25:00 (CST-6)
Location: MIAMI
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in DONLEY, TEXAS
From 13-MAY-18 16:30:00 to 13-MAY-18 16:30:00 (CST-6)
Location: CLARENDON
Magnitude: 1.00 
Reported by: Law Enforcement

Nickel to quarter sized hail reported at Clarendon College.

Hail in WHEELER, TEXAS
From 13-MAY-18 16:35:00 to 13-MAY-18 16:35:00 (CST-6)
Location: LELA
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail in OCHILTREE, TEXAS
From 13-MAY-18 16:37:00 to 13-MAY-18 16:37:00 (CST-6)
Location: PERRYTON MUNI ARPT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Thunderstorm Wind in OCHILTREE, TEXAS
From 13-MAY-18 16:39:00 to 13-MAY-18 16:39:00 (CST-6)
Location: PERRYTON MUNI ARPT
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in OCHILTREE, TEXAS
From 13-MAY-18 16:39:00 to 13-MAY-18 16:39:00 (CST-6)
Location: PERRYTON MUNI ARPT
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in LIPSCOMB, TEXAS
From 13-MAY-18 17:08:00 to 13-MAY-18 17:08:00 (CST-6)
Location: BOOKER
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in LIPSCOMB, TEXAS
From 13-MAY-18 17:11:00 to 13-MAY-18 17:11:00 (CST-6)
Location: LIPSCOMB
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in OCHILTREE, TEXAS
From 13-MAY-18 17:11:00 to 13-MAY-18 17:11:00 (CST-6)
Location: TWICHELL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in GRAY, TEXAS
From 13-MAY-18 17:25:00 to 13-MAY-18 17:25:00 (CST-6)
Location: ALANREED
Magnitude: 1.25 
Reported by: Broadcast Media

Half Dollar sized hail reported along I-40 in Alanreed.

Hail in LIPSCOMB, TEXAS
From 13-MAY-18 17:25:00 to 13-MAY-18 17:25:00 (CST-6)
Location: LIPSCOMB
Magnitude: 2.75 
Reported by: Public

Late picture report received of baseball sized hail.

Hail in LIPSCOMB, TEXAS
From 13-MAY-18 17:32:00 to 13-MAY-18 17:32:00 (CST-6)
Location: LIPSCOMB
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Late report of quarter to half dollar sized hail.

Hail in LIPSCOMB, TEXAS
From 13-MAY-18 18:00:00 to 13-MAY-18 18:00:00 (CST-6)
Location: LIPSCOMB
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorm Wind in LIPSCOMB, TEXAS
From 13-MAY-18 18:12:00 to 13-MAY-18 18:12:00 (CST-6)
Location: LIPSCOMB
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Estimated by law enforcement.

Hail in HEMPHILL, TEXAS
From 13-MAY-18 18:13:00 to 13-MAY-18 18:13:00 (CST-6)
Location: CANADIAN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Hail in WHEELER, TEXAS
From 13-MAY-18 19:10:00 to 13-MAY-18 19:10:00 (CST-6)
Location: ALLISON
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WHEELER, TEXAS
From 13-MAY-18 19:13:00 to 13-MAY-18 19:13:00 (CST-6)
Location: ALLISON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public