textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 103 PM CDT Fri Oct 2 2026

- Wetter and slightly cooler conditions are expected into early next week due to a frontal passage and a multi-day rainfall event that gradually shifts toward the coast by late this weekend.

- A Coastal Flood Statement is in effect for tidal runup ahead of and after high tide tonight at 127 AM.

- Isolated flash flooding will remain a concern through the weekend across all of Deep South Texas, especially in areas that have already received several inches of rain, and along the coast into early next week.

DISCUSSION

Issued at 103 PM CDT Fri Oct 2 2026

Unsettled weather has arrived, with mostly beneficial rainfall overnight and a few locations where heavier rain and flash flooding was observed, mainly across southeastern Starr County.

The slow-moving surface front continues to work towards the lower Texas coast, interacting with deep tropical moisture and humid southeasterly flow off the Gulf to continue rain chances this weekend. A coastal trough of low pressure is expected to develop by late this weekend into early next week behind the front, increasing the threat of heavy rainfall along the coastal counties Sunday into Tuesday. Overall, the chance of rain continues into late next week, mainly with sea breeze or diurnally driven streamer showers. Expect generally northerly winds through the forecast period and near to slightly below normal temperatures.

Areas of advanced drought conditions may experience excessive runoff and flash flooding where any heavy rain persists, especially across the brush country and portions of the upper valley, where heavier rain has already occurred and flash flooding is generally more common.

The Weather Prediction Center has issued a Slight Risk (at least 15 percent chance) for flooding rainfall for areas along and west of US-281/I-69C through tonight, with a Marginal Risk (at least 5 percent chance) for flooding rainfall for locations east. There remains a Marginal Risk for flooding rainfall Saturday into Monday for all of Deep South Texas, and along the coast and lower valley Monday into Tuesday.

The most likely rainfall amounts from today into Sunday morning are around 1 to 3 inches across all Deep South Texas and the Rio Grande Valley, with an additional one-half inch to 2 inches along and west of US-281/I-69C and 2 to 4 inches of rainfall east of US-281 expected Sunday into Tuesday.

Locally higher amounts are possible where any heavier rainfall persists, with the latest probabilistic guidance of higher end (10 percent chance) 48-HR rainfall amounts of 3-5 inches across all of Deep South Texas and the Rio Grande Valley into Sunday morning and 2-3 inches across areas along and west of US-281/I-69C Sunday through Tuesday. For areas east of US-281, especially along the coast, the latest probabilistic guidance shows higher end (10 percent chance) 48-HR rainfall amounts of 3-6 inches Sunday into Tuesday.

Will continue to monitor beach and marine hazards over the weekend, with a potential for tidal run-up near high tides beginning tonight and an elevated risk of life-threatening rip currents by Sunday into next week. A Coastal Flood Statement has been issued for tonight and another may be needed Saturday night. A Coastal Flood Advisory may be needed.

AVIATION

(18Z TAFS) Issued at 103 PM CDT Fri Oct 2 2026

VFR conditions are generally expected to prevail through the TAF period, with MVFR ceilings and periodic showers or thunderstorms possible late tonight into Saturday morning. Light northerly winds are settling into Deep South Texas, but may become variable at times, especially near any showers or thunderstorms.

MARINE

Issued at 103 PM CDT Fri Oct 2 2026

A slow-moving frontal boundary approaches coastal waters into tonight before stalling through the weekend, with a coastal trough of low pressure developing into next week. Light to moderate northerly winds are working into the coastal waters with a taste of Fall-like conditions and periods of heavy rainfall and reduced visibility becoming more frequent into Sunday night and through Monday night. Marine conditions may deteriorate again Monday and Tuesday due to the surface low and coastal trough with Small Craft Advisories potentially needed.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 78 91 76 88 / 80 90 80 80 HARLINGEN 73 92 72 88 / 70 80 80 90 MCALLEN 77 92 76 87 / 60 70 90 90 RIO GRANDE CITY 74 90 73 85 / 80 60 90 80 SOUTH PADRE ISLAND 81 87 80 86 / 80 90 90 80 BAYVIEW/PORT ISABEL 77 90 75 88 / 70 80 90 80

BRO WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.