Two separate rounds of severe thunderstorms developed the afternoon and evening of the 18th ahead of a vigorous upper level trough. By mid-afternoon, a dryline ignited widely scattered supercell thunderstorms from near Childress south to near Aspermont.  Marginally severe hail was common with these supercells. One storm south of Guthrie produced a funnel cloud observed by storm chasers. As the dryline retreated early in the evening, a left-moving supercell organized in northwest Garza County and raced north-northeast at highway speeds for the next 2.5 hours accompanied by large hail up to golfball size and severe winds.
A second and more extensive round of thunderstorms emerged late on the 18th across the southwest South Plains as a Pacific cold front collided with the retreating dryline.  The result was an extensive squall line that at one point extended from the Oklahoma Panhandle south to the western Permian Basin. Strong low-level shear in the vicinity of this squall line resulted in the formation of at least three persistent, non-tornadic circulations as observed by the NWS-LBB WSR-88D. One of these circulations was sampled in high detail by research meteorologists from Texas Tech University near Reese Center using mobile Doppler radars and high resolution surface stations (sticknets). The mobile data collected suggests these vorticies were likely gustnadoes producing very localized winds up to 78 mph. Shortly after midnight CST, the squall line intensified in the southeast Texas Panhandle where downburst winds of at least 74 mph caused numerous instances of mostly minor structural damage in Memphis.

Funnel Cloud in KING, TEXAS
From 18-MAR-12 16:17:00 to 18-MAR-12 16:17:00 (CST-6)
Location: GUTHRIE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser broadcasted live video of a funnel cloud and rapidly rotating wall cloud about 16 miles south of Guthrie.

Hail in FLOYD, TEXAS
From 18-MAR-12 19:03:00 to 18-MAR-12 19:05:00 (CST-6)
Location: FLOYDADA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Fire department personnel estimated quarter size hail at 1903 CST and golfball size hail at 1905 CST in Floydada. No damage was reported.

Thunderstorm Wind in GARZA, TEXAS
From 18-MAR-12 18:11:00 to 18-MAR-12 18:11:00 (CST-6)
Location: SOUTHLAND
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A NWS co-op observer in Southland estimated straight line winds of 60 mph. No damage was reported.

Hail in CHILDRESS, TEXAS
From 18-MAR-12 15:05:00 to 18-MAR-12 15:05:00 (CST-6)
Location: TELL
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement estimated quarter size hail in Tell. No damage was reported.

Hail in CHILDRESS, TEXAS
From 19-MAR-12 01:37:00 to 19-MAR-12 01:37:00 (CST-6)
Location: CHILDRESS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement estimated dime to quarter size hail in Childress. No damage was reported.

Hail in CHILDRESS, TEXAS
From 18-MAR-12 16:09:00 to 18-MAR-12 16:09:00 (CST-6)
Location: LONNIE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement estimated golfball size hail ten miles north of Childress along Highway 83. No damage was reported.

Hail in CHILDRESS, TEXAS
From 18-MAR-12 15:37:00 to 18-MAR-12 15:37:00 (CST-6)
Location: LONNIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser estimated one inch diameter hail seven miles north of Childress. No damage was reported.

Thunderstorm Wind in HALL, TEXAS
From 19-MAR-12 00:57:00 to 19-MAR-12 01:00:00 (CST-6)
Location: MEMPHIS
Magnitude: 64.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Destructive straight line winds measured up to 74 mph by a KVII-TV mesonet in Memphis resulted in numerous instances of mostly minor damage throughout the town.  The most visible damage was caused after a tin roof was lifted and thrown into a nearby health clinic collapsing a small exterior wall.  Also, portions of the high school football stadium press box were removed.  The majority of the damage reports involved downed tree limbs, power lines and road signs.  Some fences were also blown over and roofs were reported to have sustained generally minor damage.  No injuries were reported.

Hail in LUBBOCK, TEXAS
From 18-MAR-12 18:20:00 to 18-MAR-12 18:20:00 (CST-6)
Location: SLATON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media relayed a report of quarter size hail in Slaton.

Hail in KING, TEXAS
From 18-MAR-12 16:48:00 to 18-MAR-12 16:48:00 (CST-6)
Location: GUTHRIE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A storm chaser measured quarter size hail 12 miles east-southeast of Guthrie. No damage was reported.

Hail in LAMB, TEXAS
From 18-MAR-12 21:42:00 to 18-MAR-12 21:42:00 (CST-6)
Location: LITTLEFIELD
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Post Office

A postal employee estimated nickel size hail near Littlefield.

Thunderstorm Wind in GARZA, TEXAS
From 18-MAR-12 17:45:00 to 18-MAR-12 17:55:00 (CST-6)
Location: GRAHAM CHAPEL
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

From 1745 CST to 1755 CST, a Texas Tech University West Texas Mesonet site near Graham measured severe wind gusts ranging from 65 to 73 mph.

Thunderstorm Wind in BRISCOE, TEXAS
From 18-MAR-12 23:49:00 to 18-MAR-12 23:49:00 (CST-6)
Location: SILVERTON
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Reported by broadcast media. No damage was reported.

Thunderstorm Wind in BRISCOE, TEXAS
From 18-MAR-12 19:35:00 to 18-MAR-12 19:35:00 (CST-6)
Location: SILVERTON
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured by the Texas Tech University West Texas Mesonet near Silverton.

Thunderstorm Wind in LUBBOCK, TEXAS
From 18-MAR-12 18:32:00 to 18-MAR-12 18:32:00 (CST-6)
Location: MIDWAY
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Fire department personnel estimated straight line winds of 65-75 mph three miles east of Ranson Canyon. No damage was reported.

Thunderstorm Wind in LUBBOCK, TEXAS
From 18-MAR-12 22:39:00 to 18-MAR-12 22:39:00 (CST-6)
Location: REESE AFB
Magnitude: 68.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Texas Tech University researchers measured a wind gust to 78 mph associated with a gustnado along a leading edge of a squall line near Reese Center.

Thunderstorm Wind in HALL, TEXAS
From 19-MAR-12 00:25:00 to 19-MAR-12 00:25:00 (CST-6)
Location: TURKEY
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured by the Texas Tech University West Texas Mesonet site near Turkey.