Deep tropical moisture, a series of upper level disturbances, and a pronounced low level jet streak have produced three days of on and off rainfall across the Rio Grande Valley and Deep South Texas. The big hitter occurred early Sunday, September 19th, when a persistent band of tropical rains set up camp between Brownsville and the east side of Harlingen, dumping 4 to 7 inches of rain in a 3 to 5 hour span and flooding a number of communities and dozens of roads especially between Brownsville and Los Fresnos, particularly those that drain poorly. Perhaps one hundred homes from Brownsville to San Benito were flooded, with dozens of residents evacuating to shelters for several days after the rains ended and a slow drainage began.

Flash Flood in CAMERON, TEXAS
From 19-SEP-10 05:00:00 to 19-SEP-10 11:00:00 (CST-6)
Location: VILLA NUEVA
Flood cause: Heavy Rain
Property damage: 5.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Upper level energy, low level convergence, and a possible overnight low level jet stream of extremely moisture laden air from the Gulf of Mexico produced prolonged torrential rains across south central Cameron County between 2 and 7 AM CST September 19th.  The area shifted to the east and northeast between 7 and 8 AM CST, but not before dumping 5 to 7 inches of rain from Brownsville to San Benito and creating extensive flooding, impacting perhaps 100 or more structures, particularly in poorly draining areas.
Impacts included: Up to 60 homes with water incursion in Colonia Galaxia in West Brownsville along Military Highway; several homes with water in them in the nearby subdivision of Quail Hollow; 37 residents evacuated from 9 flooded homes in Laureles (2.5 miles northwest of Los Fresnos); several homes flooded in the Green Valley Farms area along FM 510 near San Benito, including one location where 17 small mixed-breed dogs were rescued.  Dozens of roads were closed temporarily or, in some cases, through the day.  Notable closures included Paredes Line Road just north of Ruben Torres in Brownsville, Pablo Kisel near the Morrison Blvd. intersection in Brownsville, FM 1575 near/at State Highway 100 in Los Fresnos, and portions of State Highway 345 between San Benito and Rio Hondo.  The Frontage Road near Price Road, along Federal Highway 77 in Brownsville had 2 to 3 feet of water well after the rains ended; notable poor draining roads in downtown Brownsville had similar high water.
Though the rains ended between 8 and 9 AM CST, significant poor drainage flooding continued through 11 AM CST and pockets of flooding remained into the morning of September 20th.  Dozen of pumps equipment were borrowed from Hidalgo County to assist with clearing water in poor drainage locations for the next few days.
Damage estimates will be into the $millions [final numbers available later this autumn].  Fortunately, no fatalities or injuries were reported as a direct consequence of the rains.

Heavy Rain in CAMERON, TEXAS
From 19-SEP-10 04:00:00 to 19-SEP-10 09:30:00 (CST-6)
Location: DEL MAR
Property damage: 50.00K
Crop damage: 0.00K
Reported by: ASOS

Heavy rainfall associated with a slow moving convergence zone slid east from what had been a train of 5 to 7 inches in 5 hours a bit farther west in Cameron County (Brownsville to San Benito).  Between South Padre Island and Laguna Atascosa/Arroyo City, measured and estimated 3 to 5 inches of rain produced more nuisance flooding with up to 2 feet of water covering Padre Boulevard (Town of South Padre Island), a known poorly draining road which frequently experiences minor flooding.  As of this writing, no significant damage was reported from the heavy rains in these areas.