Scattered thunderstorms developed late this afternoon ahead of a dryline, initially in the Rolling Plains and then farther west and in greater number across the southern South Plains through late evening.  Strong instability and moderate wind shear resulted in many of these storms becoming supercells, some with destructive hail to 3 inches in diameter, but very few severe wind gusts were reported.  The south side of Lubbock was especially hard hit by very large hail that fell for up to 15 minutes in some locales.  Total losses to homes and vehicles in Lubbock alone could exceed $30 million.  Some of these supercell storms were stationary at times which led to torrential rain, flash flooding and at least two road closures.

Hail in COTTLE, TEXAS
From 19-MAY-18 16:20:00 to 19-MAY-18 16:20:00 (CST-6)
Location: PADUCAH
Magnitude: 1.00 
Reported by: Storm Chaser

Damage information was not available.

Hail in DICKENS, TEXAS
From 19-MAY-18 18:00:00 to 19-MAY-18 18:00:00 (CST-6)
Location: MC ADOO
Magnitude: 0.75 
Reported by: Public

No damage was reported, but heavy rain of 1.6 inches was measured in addition to minor flooding.

Hail in LUBBOCK, TEXAS
From 19-MAY-18 18:10:00 to 19-MAY-18 18:12:00 (CST-6)
Location: SLATON
Magnitude: 2.75 
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A swath of very large hail from golf ball size to at times baseballs accompanied a stationary supercell thunderstorm in southeast Lubbock County.  Photos from residents in Slaton indicated sporadic damage to some vehicles, with unknown damage elsewhere along the hail's footprint.

Hail in LUBBOCK, TEXAS
From 19-MAY-18 19:09:00 to 19-MAY-18 19:37:00 (CST-6)
Location: SLIDE
Magnitude: 3.00 
Property damage: 30.00M
Crop damage: 0.00K
Reported by: NWS Employee

A pair of nearly stationary supercell storms inflicted heavy tolls on thousands of residents across South Lubbock.  The largest hail from tennis ball to just over baseball size occurred along a swath from near Quaker Avenue and 130th Street to Slide Avenue and 122nd Street.  On both sides of this line and extending outwards for a few miles, hail from quarter size to golf ball size was common.  With very little storm movement, large hail fell for up to 15 minutes at some locations causing even greater damage.  In Lubbock's Vintage Township alone, it was estimated that every home would require a new roof.  Preliminary insurance data indicated approximately 4000 auto claims were filed, with an estimated 1200 homes potentially in need of new roofs.  Many area auto body shops were required to work overtime to meet the onslaught of customers.  Fortunately, very little wind accompanied the hail which prevented even greater damage to the siding and windows of most homes and buildings.

Hail in CROSBY, TEXAS
From 19-MAY-18 20:40:00 to 19-MAY-18 20:40:00 (CST-6)
Location: KALGARY
Magnitude: 1.75 
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Public

Many windshields were broken in White River Lake and at least one house window was shattered.

Flash Flood in DICKENS, TEXAS
From 19-MAY-18 21:30:00 to 20-MAY-18 00:00:00 (CST-6)
Location: SPUR
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flowing water was reported over several sections of FM Road 834 northwest of Spur.  The road was temporarily closed overnight until flooding receded.

Hail in LUBBOCK, TEXAS
From 19-MAY-18 20:45:00 to 19-MAY-18 21:20:00 (CST-6)
Location: WOLFFORTH
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

A swath of large hail up to golf ball size trekked east from Wolfforth to southwest Lubbock.  Most of the hailstones were sub-severe in size. No known damage accompanied this round of hail.

Hail in LYNN, TEXAS
From 19-MAY-18 22:55:00 to 19-MAY-18 22:55:00 (CST-6)
Location: TAHOKA
Magnitude: 1.75 
Reported by: Law Enforcement

Damage information was not available.

Thunderstorm Wind in LAMB, TEXAS
From 20-MAY-18 00:55:00 to 20-MAY-18 00:55:00 (CST-6)
Location: AMHERST
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured by a Texas Tech University West Texas mesonet.

Flash Flood in KENT, TEXAS
From 19-MAY-18 23:05:00 to 20-MAY-18 01:00:00 (CST-6)
Location: GIRARD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Highway 70 between Jayton and Spur was impassable due to mud and debris flows from floodwaters.

Flash Flood in DICKENS, TEXAS
From 19-MAY-18 18:00:00 to 19-MAY-18 19:30:00 (CST-6)
Location: BROADWAY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Torrential rain resulted in flowing water across US Highway 82 in far western Crosby County and disrupted travel for nearly one hour.  Radar indicated a maximum of four inches of rain fell in nearby eastern Crosby County, but no reports of flooding were available in this area.

Flash Flood in TERRY, TEXAS
From 20-MAY-18 01:40:00 to 20-MAY-18 03:15:00 (CST-6)
Location: NEW MOORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Many rural roads in southeast Terry County were flooded following two to six inches of rain that fell in the span of two hours.  Thick mud deposits were commonplace and required removal in the following days.