textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 130 PM CDT Sat Sep 12 2026

- Hot, rain-free, and breezy conditions will continue through mid week across Deep South Texas. This may result in elevated fire weather concerns across portions of the region, mainly during the afternoon hours.

- A Heat Advisory remains in effect for portions of the region through 6 PM this evening. A Small Craft Advisory remains in effect for the Laguna Madre and nearshore Gulf waters through 8 PM this evening.

- Low to medium (20-50%) precipitation chances are in store Wednesday through the weekend across the region.

DISCUSSION

Issued at 130 PM CDT Sat Sep 12 2026

Triple-digit heat will continue to be the primary weather concern across Deep South Texas through next week as the region remains under the influence of ridging aloft. Expect unseasonably hot temperatures, near record breaking at times, to continue each day across the region, with the exception being along the lower Texas beaches. The combination of temperatures and humidity will result in heat index values ranging from 109-114 degrees, with the highest values closer to the immediate coast. The prolonged period of unseasonable heat will also result in a major (level 3 of 4) to extreme (level 4 or 4) heat risk for the entire region. Expect additional heat headlines through at least early next week. If spending time outdoors, continue to practice heat safety to prevent heat related illnesses.

Guidance continues to highlight a pattern change by mid to late week, as an upper level trough translates nearby. In combination with diurnal instability and the presence of high moisture content, this would support some low to medium rain chances (around 20-40%) across the region. Rainfall amounts remain fairly low/light at this time, but there should be better clarity as guidance comes into agreement over the next several days.

AVIATION

(18Z TAFS) Issued at 130 PM CDT Sat Sep 12 2026

VFR will prevail through the forecast period at all TAF sites. Expect southeasterly winds around 15 knots with occasional higher gusts up to 25 knots through late this evening before falling to around 5-10 knots tonight. Winds should increase once again tomorrow by mid to late morning.

MARINE

Issued at 130 PM CDT Sat Sep 12 2026

A Small Craft Advisory remains in effect through this evening for the Laguna Madre and nearshore Gulf waters as breezy winds persist due to an enhanced pressure gradient. Small Craft Exercise Caution conditions will continue through the weekend, mainly during the late morning into early evening hours. Conditions should improve slightly next week, although brief Small Craft Exercise Caution conditions may continue during the afternoon hours. Rain chances increase by mid week across the Gulf waters.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 82 98 81 97 / 10 30 10 20 HARLINGEN 78 102 78 101 / 10 20 10 10 MCALLEN 82 103 81 103 / 0 10 0 0 RIO GRANDE CITY 80 105 79 104 / 0 0 0 0 SOUTH PADRE ISLAND 83 90 83 90 / 10 30 10 10 BAYVIEW/PORT ISABEL 80 96 79 96 / 10 30 10 10

BRO WATCHES/WARNINGS/ADVISORIES

TX...Heat Advisory until 6 PM CDT this evening for TXZ250>255-351- 353>355.

GM...Small Craft Advisory until 8 PM CDT this evening for GMZ130-132- 135-150-155.