textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 634 PM CDT Tue Jul 14 2026

- Seasonal heat (based on the 1991-2020 average) with overall heat risk for the region remaining in the moderate (level 2 of 4) range through Sunday, with some potential for major (level 3 of 4) heat risk early next week but with low confidence.

- Minimal rain chances and very low rainfall rates/totals through Wednesday night for northern Zapata through northern Brooks County...uncertainty for some showers across the lower RGV early next week - Generally moderate intensity south-to-north longshore currents with a few embedded rip currents through Friday, with some improvement over the weekend.

DISCUSSION

Issued at 112 PM CDT Tue Jul 14 2026

This afternoon through Thursday: The RGV looks to remain dry as the combination of a weak 500 mb closed off low, robust tropical moisture, and mesoscale forcing maintains a prodigious rainfall event that ebbs and flows across portions of the Edwards Plateau to the Big Bend region for the next couple of days. While the Valley remains dry, there are some hints that remnants of the convection could slide into the northern ranchlands, mainly from Zapata to northern Brooks County overnight tonight and Wednesday. Ensemble probabilities of very low QPF (0.01") do sneak above 50% (LREF model) in some pockets of these areas, while the NBM 5.0 keeps non-mentionable chances (generally below 10%) for nearly all of the period. Sometimes, southeast-moving cells/MCS type systems can reach parts of our region, so would not be surprised if we may need to edit some higher chances into these areas both overnight tonight and again on Wednesday.

Otherwise, it's more of the same with seasonal heat (95 to 100 from east to west by day, mid 70s rural areas and upper 70s urban by sunrise) and the late morning through early evening southeast breeze under a mix of scattered low clouds and residual cirrus nosing southward from the aforementioned convection.

At the beaches, the steady southeast to south wind and wave pattern will maintain mainly moderate south-north longshore currents with embedded rips.

Thursday night through Sunday night: The upper low continues to spin, but nudges into west and southwest Texas and takes the better forcing with it, as the back side of the larger ridge that extends from the central/northern Plains into the eastern Gulf nudges westward across the Texas coast and especially the southern tip. This ends any rain chances but maintains the persistent seasonal heat along with the daily late morning through early evening gusty southeast breezes for most. Beach conditions should also remain status quo, though the back-building of the surface ridge to the western Gulf should begin reducing both waves and currents later Saturday and Sunday.

Monday through Tuesday: Model differences continue to show up, with the deterministic GFS more pronounced with a "new" upper low setting up across north-central Mexico and extending toward the Tamaulipas coast as the heat-dome 500 mb ridge sets up shop from the southern Plains into the central Rockies. This new upper low, if it does set up, help force deeper tropical moisture into the region from northeast Mexico late Monday through Tuesday. GFS ensembles from the 06Z run suggested 50% chances of 0.01" across the lower RGV. The ECMWF, meanwhile, is holding onto its drier (and gradually hotter) solution with the 500 mb ridge connecting from the central/northern Rockies through the eastern two-thirds of Texas and northeast Mexico, with no hint of a new upper low in north-central Mexico.

As of now, the NBM has not caught on or caught up with the GFS trends - so the forecast continues to show slightly hotter daytime temperatures Monday-Tuesday with mostly sunny skies. Note that this may change over the next few days, so stay tuned.

AVIATION

(00Z TAFS) Issued at 634 PM CDT Tue Jul 14 2026

Moderate and gusty southeast winds with widespread cirrus clouds prevail across Deep South Texas early this evening. Southeast winds will decrease later this evening and become lighter overnight. Winds are expected to increase around 15 knots mid to late Wednesday morning with some gusts near 25 knots in the afternoon. VFR conditions will continue through late this evening into the overnight hours. MVFR ceilings will be possible late tonight into early Wednesday morning. Will continue to mention a TEMPO for all terminals between 08-12Z. Otherwise, VFR conditions are expected for the next 24 hours.

MARINE

Issued at 112 PM CDT Tue Jul 14 2026

This afternoon through Sunday Night: Southeast flow is the story, with diurnal speeds shifting caution conditions (15-20 kt and gusty) from the Laguna Madre (late morning through sunset or so) to most of the Gulf waters (mid evening through pre-dawn). With the surface high nudging westward toward the coast later in the weekend, overnight winds over the 0-60 nm legs could slip toward or just below 15 knots. Otherwise, during the lower diurnal wind periods, 10-15 knots will do it.

As for waves...there is a window of 4 to 5 foot Gulf waves Thursday into Friday due to the persistence of the aforementioned flow, before setting back toward 3 feet later in the weekend as the ridge nudges toward the coast and reduces the gradient.

HYDROLOGY

Issued at 112 PM CDT Tue Jul 14 2026

The ongoing and forecast heavy rainfall pockets along the Rio Grande between Amistad and Eagle Pass, as well as through runoff into the river from any flash floods and tributaries, is now forecast to produce a flood wave (at least minor flooding at some gauges) that will track down river through Laredo and along the Zapata line before emptying into Falcon Lake, which should see at least some minor rises in water levels (known as conservation levels) beginning later this week and into next week. The Rio Grande between the northern end of the lake and the Zapata/Webb County line will run fast and fairly high - not enough to produce landslide flooding but enough to impact any equipment or other items in the river (USA side). For details on the flood forecasts north of Falcon Lake, go to https://water.noaa.gov and click on the gauge locations along the Rio Grande.

CLIMATE

Issued at 112 PM CDT Tue Jul 14 2026

If it's July, it's hot in the Valley (unless we get beneficial rains from a tropical event or a similar disturbance to what is occurring across the Big Bend/Edwards Plateau). But just how hot? So far (through the 13th), we've been running a little 0.5 to 1.8 degrees above the 1991-2020 30-year average, which is the highest on record dating back to the early 20th century. So...for the periods of record, most Valley locations are within the top 10% hottest on record. The numbers so far for available locations, day and night combined, through the 13th:

Location(records since) 2026 avg. Rank Prior Record(year)

Brownsville (1878) 87.6 3 88.2(2023) McAllen (1942) 89.8 6 92.0(2009) Harlingen (1912) 86.0 22 89.1(2016) Weslaco(1914) 87.7 3 88.5(2022) Port Mansfield(1958) 85.4 6 86.8(2016)

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 81 93 81 94 / 0 10 10 10 HARLINGEN 78 94 78 95 / 0 0 10 10 MCALLEN 81 98 81 99 / 10 0 10 0 RIO GRANDE CITY 79 98 79 99 / 0 0 10 0 SOUTH PADRE ISLAND 82 87 81 88 / 0 10 10 10 BAYVIEW/PORT ISABEL 80 91 80 92 / 0 10 10 10

BRO WATCHES/WARNINGS/ADVISORIES

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