textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 148 PM CDT Tue Oct 6 2026

- Medium to likely (40-80%+) chances of rain continue along/east of US-281 through tomorrow, becoming a region-wide low to medium (30-60%) on Thursday before gradually reducing in extent and chances over the weekend.

- The National Hurricane Center (NHC) indicates a high (90%) chance of tropical development of a low pressure system, currently situated over the southwestern Gulf, through the next 7 days.

- While direct impacts are not expected across deep south Texas, there is an ongoing risk of life-threatening rip currents, elevated surf and minor coastal flooding, particularly towards the later half of this week and into this weekend.

- Mostly minor risks of heat-related illnesses (level 1/4) become moderate (level 2/4) by next Monday as deep low-level moisture returns.

DISCUSSION

Issued at 148 PM CDT Tue Oct 6 2026

Persistent coastal troughing along a stationary boundary and a little bit of divergence aloft along/near the coast are expected to maintain medium to likely (40-80%+) chances of intermittent light to moderate showers and perhaps a few thunderstorms across the coastal counties tonight, expanding inland to along/east US-281 tomorrow morning into the afternoon hours. Due to deep moisture (PWAT values > 2.0 in.) remaining in place over the southeastern portions of the region, the highest chances of rain and the potential for brief heavy rain persist closer to the coast during this timeframe. The stationary boundary begins to move further offshore tomorrow night, but a mid/upper level low moving into western Texas shifts low to medium (30-60%) chances of rain from along/east I-69 E tomorrow night to most of the region on Thursday.

Troughing aloft continues low to medium (30-40%) chances of rain along/east of US-281 on Friday, but should be on the lighter side as subsidence increases aloft, west of a developing tropical system over the central Gulf, discussed further below. This should help cut down on chances of rain over the weekend before low (15-30%) chances of rain return in the beginning of next week as a bit of vorticity aloft and southeasterly surface winds return and enhance moisture content back to above average.

In the meantime, NHC continues monitoring the development of a broad area of low pressure located over the southwestern Gulf, indicating a high (90%) chance of tropical development over the next 7 days. While direct impacts are not likely to deep south Texas, a continued threat of rip currents, elevated surf and minor coastal flooding, resulting from increased winds and a northeasterly fetch over the Gulf, is expected to continue through most of the forecast. In the immediate term, a medium risk of rip currents persists through tomorrow afternoon. Yet, this risk is likely to become high into the middle and later parts of this week as long period swells and elevated wave heights arrive to the Lower Texas coast.

Otherwise, high temperatures increase from the upper 80s further east (and low 90s further west) today to mostly the low/mid 90s by tomorrow, perhaps warming a bit further in the early parts of next week. Mostly minor risks of heat-related illnesses persist through this weekend, becoming a moderate risk by next Monday as moisture returns, deteriorating heat indices to near 100-110 F. Overnight lows in the 70s prevail.

AVIATION

(18Z TAFS) Issued at 1220 PM CDT Tue Oct 6 2026

VFR conditions and light northerly winds should prevail through most of the 18 Z TAF cycle, though brief periods of light to moderate shower activity, and perhaps a thunderstorm or two, are possible at KBRO and KHRL, which could reduce ceilings and visibility to MVFR at times. Meanwhile, KMFE should remain dry, though a light shower or two is not out of the question.

MARINE

Issued at 148 PM CDT Tue Oct 6 2026

Moderate to fresh northeasterly winds are likely to maintain moderate (3-5 foot) seas and periods of Small Craft Exercise Caution (SCEC) conditions through tomorrow night. Thursday into Friday, a pressure gradient tightens and enhances northeasterly winds to fresh to strong, with Small Craft Advisory (SCA) headlines becoming likely, especially across the offshore Lower Texas Gulf coastal waters (20-60 nm). This is in response to a broad low pressure system, currently situated over the southwestern Gulf, which NHC has forecast a high (90%) chance of undergoing tropical development within the next 7 days. While winds are not anticipated to strengthen beyond strong, there is the potential for seas to rise to above 7 feet from Thursday into this weekend, likely maintaining SCA conditions across all Gulf waters (0-60 nm).

Medium to likely (50-80%+) chances of rain reduce to low to medium (30-50%) on Friday, minimizing this weekend and then increase to low to medium (20-40%) by next Monday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 77 90 77 91 / 50 80 50 60 HARLINGEN 72 92 72 93 / 30 70 40 50 MCALLEN 76 95 75 95 / 10 50 20 60 RIO GRANDE CITY 73 94 72 94 / 10 20 10 40 SOUTH PADRE ISLAND 80 86 81 86 / 80 90 60 70 BAYVIEW/PORT ISABEL 77 88 76 89 / 70 80 60 60

BRO WATCHES/WARNINGS/ADVISORIES

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