Raindrops Keep Falling...
10 to 12 inches likely in some Locations by July 9th
The torrential rains which dropped another 1 to 2 inches on portions of the Lower Rio Grande Valley through early afternoon have largely ended...for now. Areas receiving the most rain today included portions of Hidalgo, Jim Hogg, western Cameron, where local pockets of more than 2 inches of rain fell. Unofficially, local airports received lesser rain totals than on the 7th, with Brownsville/South Padre Island International leveling at 1 inch so far. Based on radar indications, it is possible that isolated locations between Rancho Viejo and Harlingen may have approached or topped 10 inches for July so far. Updated values will be available on July 9th.
After several days of steady, drought-relieving days of moderate area wide rainfall, enhanced energy associated with a now elongated upper level disturbance helped set up even more prodigious rainfall on July 7th, which set up in nearly stationary lines, or "trains", of showers and thunderstorms, which moved across the same areas for several hours at a time. The first "train" affected a large portion of Hidalgo County, dropping generally between 1 and 2 inches of rain during the morning commute. The second, more pronounced line developed in northeast Tamaulipas, then surged into western Cameron, Willacy, and Kenedy Counties from late morning through mid afternoon.
The second surge, which dropped generally between 2 and 4 inches of rain along and within 10 miles of Federal Highway 77 between Rancho Viejo and Raymondville, on into Kenedy County, produce numerous instances of nuisance type urban flooding in areas with poor drainage. Numerous reports of high water on roads were received, including several in Harlingen and a few in Brownsville and Raymondville.
A summary of rainfall from July 1st through early on July 8th, not including the day's totals, can be found here. Additional updates will be provided each morning until the event concludes.
Subtle changes in the pattern will gradually allow more typical summer weather to return to the Valley by the end of the week. Unfortunately, the combination of continued deep layered moisture with an unstable air mass will promote numerous showers and scattered thunderstorms again on the 9th and perhaps on the 10th as well. While rain "trains" are not expected, individual stronger storm cells may well produce locally 2 to 3 inches of rain once again. Should these rains fall on already saturated ground, minor flooding and perhaps flash flooding could develop each afternoon.
In rural areas, additional rains could produce rapid rises of streams, creeks, and arroyos along with localized flooding of low water crossings. Residents of Deep South Texas and the Lower Rio Grande Valley should continue to monitor weather conditions through Wednesday the 9th, and remain alert to flash flood warnings or flood advisories for their area.
If high water is observed, do not drive your vehicle into areas where the water covers the road. The depth of the water may be too great to allow you to cross safely. If travels take you near known poor drainage locations, consider bringing a life jacket along. Always remember: Don't become a statistic. Turn around, Don't DrownTM!