Deep tropical moisture pooled ahead of a dissipating late season front across the ranchlands, and combined with an impulse of jet stream energy during the afternoon and evening hours of May 11th.  This resulted in a broken area of diurnally driven late afternoon showers and thunderstorms, which was followed by more widespread and slow moving thunderstorms after sunset which ultimately developed into a convective system that produced flash flooding concentrated from southeast Starr and southwest Hidalgo counties and extended northeast through rural northern Hidalgo and eastern Brooks counties, including Linn/San Manuel, McCook, Encino, and Falfurrias.  There were at least a dozen water rescues in and near Rio Grande City, including the Las Lomas neighborhood and Garciasville, where some homes had up to 3 feet of water inside them after a likely combination of freshwater (drainage) and arroyo flooding from an estimated/measure five to seven inches of rain in two to three hours. Portions of U.S. 83 were closed in southeast Starr County, mainly from Rio Grande City to near the Hidalgo County line, due to standing water of 2 to 4 feet.  Along and near Farm to Market Road 1017 and extending southeast to areas north and east of Edinburg, including Faysville and Monte Alto, poor drainage flooding resulted in water rescues that continued well into May 12th.  The flooding was not isolated to rural areas of the Mid and Upper Valley. Torrential rains slid into the McAllen/Weslaco/Donna area, where nuisance flooding with water levels up to two feet was noted well after midnight when 2 to 3 inches of rain piled up. Significant flooding was noted in Hebbronville when storms clustered just before sunset, with up to a foot of water in most areas, including some into at least one building, along with water rescues. Conditions worsened farther east in and near Falfurrias, where an estimated and measured 5 to 7 inches resulted in minor to moderate urban flooding, with several water rescues in one to two feet of water throughout town just after sunset. High standing water, 1 to 1 �� feet, continued through the night.
Embedded within the flood-producing thunderstorm clusters were hail and damaging wind producing storms. Quarter size hail was reported with the evening storms on May 11th. In addition, a small convective vortex injected into the system near Edinburg, producing estimated wind up to 70 mph from Elsa/Edcouch to La Villa, which caused damage to older structures, trees (mainly ash), and power lines and poles.

Flash Flood in BROOKS, TEXAS
From 11-MAY-15 19:30:00 to 11-MAY-15 22:00:00 (CST-6)
Location: FALFURRIAS ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Brooks County Sheriffs Office reported 1 to 2 feet of water along Highway 281 in Falfurrias, as well as on multiple streets across Falfurrias. The high water on roadways resulted in at least 3 water rescues from stranded vehicles.

Flash Flood in STARR, TEXAS
From 11-MAY-15 20:00:00 to 12-MAY-15 01:00:00 (CST-6)
Location: ROSITA
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Starr County Sheriffs Office reported residence on Chapotito Road had 5 to 6 inches of water in it.

Flash Flood in STARR, TEXAS
From 11-MAY-15 20:00:00 to 12-MAY-15 01:00:00 (CST-6)
Location: RIO GRANDE CITY
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Starr County Sheriffs Office reported at least a dozen water rescues in and near Rio Grande City, including the Las Lomas neighborhood and Garciasville, where some homes had up to 3 feet of water inside them after a likely combination of freshwater (drainage) and arroyo flooding from an estimated/measure five to seven inches of rain in two to three hours. Portions of U.S. 83 were closed in southeast Starr County, mainly from Rio Grande City to near the Hidalgo County line, due to standing water of 2 to 4 feet.

Flash Flood in STARR, TEXAS
From 11-MAY-15 20:00:00 to 12-MAY-15 01:00:00 (CST-6)
Location: ROSITA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Starr County Sheriffs Office reported 3 feet of water on Highway 83 near the Alvarez Road.

Flash Flood in HIDALGO, TEXAS
From 11-MAY-15 21:00:00 to 12-MAY-15 03:00:00 (CST-6)
Location: LINN
Flood cause: Heavy Rain
Property damage: 2.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Hidalgo County EM reported flash flooding along and near FM 1017 and extending southeast to north and east of Edinburg, including Faysville, Monte Alto, and Linn-San Manuel. Water Along and near Farm to Market Road 1017 and extending southeast to areas north and east of Edinburg, including Faysville and Monte Alto. Roadways were covered in high water, which resulted in water entering the fire station in San Manuel and numerous water rescues. Hidalgo County EM reported that water entered the fire station in San Manuel.

Thunderstorm Wind in STARR, TEXAS
From 11-MAY-15 22:45:00 to 11-MAY-15 22:50:00 (CST-6)
Location: GARCIASVILLE
Magnitude: 43.00 EG
Property damage: 7.50K
Crop damage: 0.00K
Reported by: Law Enforcement

Starr County Sheriffs Office reported shingles blown off of a roof and damage to the walls of a structure in Alto Bonito.

Thunderstorm Wind in HIDALGO, TEXAS
From 11-MAY-15 23:00:00 to 11-MAY-15 23:05:00 (CST-6)
Location: MONTE ALTO
Magnitude: 61.00 EG
Crop damage: 50.00K
Reported by: Social Media

Public reported 60 acres of corn leveled by straight line winds at the corner of FM 493 and FM 2812.

Heavy Rain in HIDALGO, TEXAS
From 11-MAY-15 23:00:00 to 12-MAY-15 00:00:00 (CST-6)
Location: (MFE)MILLER INTL ARP
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Public reported 6 to 10 inches of water at intersections and in parking lots across Edinburg and McAllen.

Thunderstorm Wind in HIDALGO, TEXAS
From 12-MAY-15 00:20:00 to 12-MAY-15 00:30:00 (CST-6)
Location: ELSA
Magnitude: 61.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Hidalgo County EM reported widespread damage in La Villa. Multiple metal walls of a prefabricated building were peeled back and blown out 1 mile north of La Villa, a metal fence was blown down and metal canopies for recreational vehicles were blown off at Nature Resort RV Park in La Villa. Shingled roofs were peeled back, small wood and metal storage buildings were toppled over and moved from foundations. Multiple trees were downed as well as multiple cedar fences. A mobile home was shifted off the foundation blocks. A trampoline was blown into the middle of a cotton field. The press box at La Villa High School was destroyed. Numerous utility poles were downed as well.

Thunderstorm Wind in CAMERON, TEXAS
From 12-MAY-15 00:25:00 to 12-MAY-15 00:35:00 (CST-6)
Location: LA FERIA
Magnitude: 52.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

La Feria Police Department reported a utility pole leaning heavily on a palm tree due to thunderstorm wind gusts at the intersection of Frontage Road and Solis Road and a tree blown down in the alley between 7th and 8th streets.

Flash Flood in JIM HOGG, TEXAS
From 11-MAY-15 17:00:00 to 11-MAY-15 20:00:00 (CST-6)
Location: HEBBRONVILLE
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Jim Hogg County Sheriffs Office reported 6 inches to 1 foot of water on all roads in Hebbronville. 2 water rescues were from vehicles were completed and water was reported inside 1 building. Los Olmos Creek was reported to be at capacity and in danger of flowing over the roadway.

Heavy Rain in HIDALGO, TEXAS
From 11-MAY-15 23:55:00 to 12-MAY-15 00:30:00 (CST-6)
Location: WESLACO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Weslaco Police Department reported 1 foot of water on Airport Road from Business 83 to 8th Street and 1.5 to 2 feet of water at the intersection of Westgate and Pike.

Heavy Rain in HIDALGO, TEXAS
From 12-MAY-15 00:05:00 to 12-MAY-15 00:45:00 (CST-6)
Location: MERCEDES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Mercedes Police Department reported 6 to 8 inches of water at the intersections of Business 83 and Indiana and Business 83 and Washington.

Hail in STARR, TEXAS
From 11-MAY-15 21:40:00 to 11-MAY-15 21:45:00 (CST-6)
Location: RIO GRANDE CITY ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Starr County Sheriffs Office reported quarter size hail at the intersection of FM 1367 and Eisenhower Road.

Thunderstorm Wind in BROOKS, TEXAS
From 11-MAY-15 18:20:00 to 11-MAY-15 18:30:00 (CST-6)
Location: FALFURRIAS ARPT
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Brooks County Sheriffs Office reported power poles bent over along County Road 229 and Highway 285.

Thunderstorm Wind in HIDALGO, TEXAS
From 12-MAY-15 00:00:00 to 12-MAY-15 00:05:00 (CST-6)
Location: PROGRESO
Magnitude: 39.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Progresso Police Department reported a tree was blown down onto a vehicle at a residence on Watts Street in Progresso.

Thunderstorm Wind in HIDALGO, TEXAS
From 12-MAY-15 00:20:00 to 12-MAY-15 00:25:00 (CST-6)
Location: MERCEDES
Magnitude: 52.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Mercedes Police Department reported a window blown out at the outlet mall and a palm tree blown down on Dawson Street.

Flash Flood in BROOKS, TEXAS
From 12-MAY-15 01:30:00 to 12-MAY-15 04:00:00 (CST-6)
Location: FALFURRIAS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Brooks County Sheriffs Office reported water 12 to 18 inches deep on many roads in Falfurrias, including Highway 281. Water was high enough that residents could not get out of their homes.