textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 936 PM CDT Fri Sep 11 2026

- Hot, mainly dry, and at times breezy conditions will continue through Wednesday of next week.

- A Heat Advisory has been issued for all of Deep South Texas, outside of Zapata, Jim Hogg Counties, and the island from 11 AM to 6 PM CDT Saturday.

- Borderline Fire Danger Statement for Saturday due to the minimum relative humidity (RH) values coupled with the breezy winds and antecedent dry soils (see Fire Weather Section).

- A Small Craft Advisory has been issued for the Bay and Nearshore Waters from 11 AM to 8 PM CDT Saturday due to breezy southeast winds (see Marine Section).

- Record to near record-breaking temperatures are expected to continue over the next couple of days at least (see Climate Section).

- Widespread Major (level 3 of 4) to increasing areas of Extreme (level 4 of 4) Heat Risk will continue through the middle of next week.

- Widespread shower and thunderstorm chances increase Wednesday night through Friday of next week; currently there is a low- medium (20-50%) chance for showers and thunderstorms during this time.

DISCUSSION

Issued at 936 PM CDT Fri Sep 11 2026

Hot, mainly dry, and at times breezy conditions will continue to be the theme through the middle part of next week as an anomalously strong and elongated 591-594 dam heat ridge complex remains anchored over the southern U.S. This persistent and dominant feature in our pattern will continue to foster record to near record-breaking heat in the days ahead (see CLIMATE SECTION for more details). High temperatures are progged to continue to climb into the upper 90s to mid 100s through much of the forecast period with overnight lows in the 70s to lower 80s. Peak heat indices ranging between 105-115F degrees will continue to warrant day-to-day or near daily Special Weather Statements (SPSs) and/or Heat Advisories through at least this weekend. The combination of very hot temperatures during the day and very warm temperatures at night providing little relief, widespread Major (Level 3 of 4) Heat Risk to increasing areas of Extreme (Level 4 of 4) Heat Risk will be the case through the middle part of next week.

Medium range forecast models are signaling the low, non-zero chance for showers and thunderstorms along the sea breeze on Sunday. The weather pattern looks to turn wetter mid to late next week as a stonger and more widespread chance for showers and thunderstorms are possible Wednesday night through Friday. These showers and thunderstorms are associated with a nearby shortwave trough. We will continue to monitor the potential for any breakthrough rains and the potential for a wetter pattern change to develop during this time frame. Currently, we have low-medium (20-50%) chances for showers and thunderstorms during the Wednesday night to Friday timeframe.

AVIATION

(00Z TAFS) Issued at 510 PM CDT Fri Sep 11 2026

Through 00z Sunday....VFR conditions are expected to prevail through the 00z TAF cycle under clear to mostly clear skies.

Southeast winds 10-20 kts with gusts as high as 25-30 kts or so will prevail through the forecast period.

MARINE

Issued at 936 PM CDT Fri Sep 11 2026

A Small Craft Advisory is in effect for the Laguna Madre and the Nearshore Gulf Waters from 11am to 8pm CDT on Saturday due to a continuation of breezy southeasterly winds 15-25 kts gusting as high as 30 kts. These winds have also helped to drive moderate wave heights over the Gulf Waters. That said, Small Craft Exercise Caution (SCEC) conditions will be in place for the Offshore Gulf Waters on Saturday. Sunday through next week, winds will lighten up from compared to prior days. This will result in mainly moderate seas with wave heights up to 3 feet prevailing Sunday through much of next week. Outside of the winds and waves, there will be periodic chances for showers and thunderstorms through the forecast period, namely on Sunday and then to a greater degree Wednesday through Friday.

FIRE WEATHER

Issued at 936 PM CDT Fri Sep 11 2026

Borderline Fire Danger Statement (RFD) conditions will be present on Saturday. While the winds (southeasterly 15-25 mph with gusts between 30-40 mph) will meet criteria, the minimum relative humidity (RH) values will be near criteria for a Fire Danger Statement. Will monitor trends and let the next set of shifts decide. If confidence increases on the next shift(s), we'll issue a Fire Danger Statement for Saturday. Regardless, we continue to urge you to practice fire weather safety, especially given how dry it's been and how breezy it is.

CLIMATE

Issued at 936 PM CDT Fri Sep 11 2026

Record to near record-breaking temperatures are possible through at least Sunday, courtesy of a persistent and strong 591-594 dam heat ridge complex established over the southern U.S. Below is a list of the record highs from Saturday September 12th and Sunday September 13th.

Saturday September 12, 2026:

Brownsville: 100F in 1919 Harlingen: 101F in 2011 & 1930 McAllen: 103F in 1987

Sunday September 13, 2026:

Brownsville: 100F in 2023 & 1900 Harlingen: 100F in 1961, 2011, & 2023 McAllen: 104F in 1987

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 82 99 82 98 / 0 0 10 20 HARLINGEN 78 102 79 101 / 0 0 10 20 MCALLEN 82 104 82 104 / 0 0 0 10 RIO GRANDE CITY 80 106 80 104 / 0 0 0 0 SOUTH PADRE ISLAND 83 90 83 90 / 0 0 10 20 BAYVIEW/PORT ISABEL 80 97 80 96 / 0 0 10 20

BRO WATCHES/WARNINGS/ADVISORIES

TX...Heat Advisory from 11 AM to 6 PM CDT Saturday for TXZ250>255-351- 353>355.

GM...Small Craft Advisory from 11 AM to 8 PM CDT Saturday for GMZ130- 132-135-150-155.