A weak upper level disturbance, which had produced a few days of healthy thunderstorms in the western Gulf of Mexico during the final week of June, crossed the coast on June 30th and produced local downpours that flooded small portions of Cameron and Zapata/western Starr County. The disturbance combined with sea breeze influences and boundaries from activity across the Coastal Bend to enhance initial thunderstorms along the coast of eastern Willacy and Cameron County around noon. Boundaries from these storms combined with the circulation of the upper disturbance to create a system of thunderstorms which persisted in a very small area along and west of Highway 77 from Matamoros, Tamaulipas, Mexico to the north side of Brownsville, from 1 PM until a little after 5 PM. A final round of torrential rains swept through Brownsville just prior to 11 PM and dropped another inch in some areas of the city. Farther west, boundaries from stronger cells across the Rio Grande Plains near Laredo and just west of the river set up a train of storms that hugged the Rio Grande for several hours into the early evening of the 30th. A number of locations along and near Federal Highway 83 reported water across the road from near Roma to Lope��o, along the Starr/Zapata border.

Flash Flood in CAMERON, TEXAS
From 30-JUN-12 15:45:00 to 30-JUN-12 18:30:00 (CST-6)
Location: MAUDLIN ARPT
Flood cause: Heavy Rain
Property damage: 75.00K
Crop damage: 0.00K
Reported by: NWS Employee

Heavy rain fell during the afternoon hours across Brownsville. Western and downtown portions of Brownsville were especially hard hit with rainfall totals over 5 inches reported by a spotter and CoCoRaHS reports. Flash floods closed several roads, overtopped resacas, and reached into properties near and in downtown.   A trained spotter reported water in the streets and resacas out of their banks and over walls; this spotter also reported five inches of rain. A NWS employee reported that Price Road was impassible with at least a foot of water over it in western Brownsville.  Emergency manager reported water in a few homes in downtown Brownsville and resacas getting high. Emergency manager also reported that Price Road was mostly closed, Boca Chica Blvd was closed in a few spots, and a few other streets were closed as well.

Flash Flood in STARR, TEXAS
From 30-JUN-12 18:00:00 to 30-JUN-12 19:30:00 (CST-6)
Location: ROMA ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported water over the road at Highway 83, near Falcon Heights.

Flash Flood in ZAPATA, TEXAS
From 30-JUN-12 17:15:00 to 30-JUN-12 19:00:00 (CST-6)
Location: LOPENO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

At Law enforcement reported water completely covering Highway 83 at Lopeno.

Flash Flood in ZAPATA, TEXAS
From 30-JUN-12 16:00:00 to 30-JUN-12 18:15:00 (CST-6)
Location: SAN YGNACIO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Zapata County law enforcement officials reported flash flooding was occurring in northwestern Zapata County, north of San Ygnacio.  Officials reported that water and mud was flowing across HIghway 83.