The combination of boundaries in the area and an extremely unstable airmass, led to the development of explosive thunderstorms across the mid Valley, during the late evening and overnight hours (apparent temperatures at McAllen were 100 degrees F at 10 pm (C2T) with the actual temperature at just under 90 F). These thunderstorms produced excessive lightning, quarter to golf ball size hail, strong and gusty winds, and flooding across the mid Valley area.

Hail in HIDALGO, TEXAS
From 19-AUG-15 23:25:00 to 19-AUG-15 23:30:00 (CST-6)
Location: MISSION
Magnitude: 1.75 
Crop damage: 0.00K
Reported by: Law Enforcement

Palmview Police Department reported golf ball size hail near the intersection of La Homa Road and U.S. Highway 83.

Thunderstorm Wind in HIDALGO, TEXAS
From 19-AUG-15 23:33:00 to 19-AUG-15 23:45:00 (CST-6)
Location: PALMHURST
Magnitude: 43.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Mission Police Department reported power lines and large tree branches down due to strong winds at the intersection of Inspiration and FM 495 and in the 1400 block of Doherty.

Thunderstorm Wind in HIDALGO, TEXAS
From 19-AUG-15 23:40:00 to 20-AUG-15 00:30:00 (CST-6)
Location: SHAYLAND
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Estimated thunderstorm wind gusts of 50 to 60 mph knocked down trees and power lines across Pharr. The Pharr Police Department reported trees blown down at the intersection of Jackson and Ridge roads and on North Palm Road.

Flash Flood in HIDALGO, TEXAS
From 20-AUG-15 00:04:00 to 20-AUG-15 01:30:00 (CST-6)
Location: MADERO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Between 4 to 6 inches of rain fell across Alton, Mission, and parts of McAllen leading to pockets of water up to three feet deep. Mission Police Department reported flood waters up to the tops of car tires throughout much of the city of Mission. Hidalgo County Sheriff's Office reported flooding resulting in impassable roads at the intersection of U.S.  83 and 23rd Street and U.S. 83 and Ware Road. The city of Alton sent one truck to pump water near Glasscock Boulevard and Main Street.

Heavy Rain in HIDALGO, TEXAS
From 20-AUG-15 01:00:00 to 20-AUG-15 04:00:00 (CST-6)
Location: WESLACO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Between 4 and 7 inches of rain fell over a three hour period across the Weslaco area. Weslaco Co-Op observer reported over 5 inches of rain.

Lightning in HIDALGO, TEXAS
From 20-AUG-15 00:00:00 to 20-AUG-15 02:00:00 (CST-6)
Location: MC ALLEN
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Emergency Manager

At least five homes were struck by lightning and burned in spots in the McAllen Metro and Weslaco areas, some with considerable damage. Numerous lightning strikes were reported throughout Hidalgo County, resulting in utility pole and tree fires, and more than 30,000 residents without power at the peak of the storms.

Thunderstorm Wind in HIDALGO, TEXAS
From 20-AUG-15 00:45:00 to 20-AUG-15 01:15:00 (CST-6)
Location: WESLACO
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Estimated thunderstorm wind gusts of 50 to 60 mph knocked down trees and caused roof and antenna damage across the middle Rio Grande Valley, including the city of Weslaco.

Hail in HIDALGO, TEXAS
From 19-AUG-15 23:25:00 to 19-AUG-15 23:30:00 (CST-6)
Location: MISSION
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Law Enforcement

Mission Police Department reported quarter size hail throughout much of the city of Mission.