textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 522 AM CDT Tue Jul 7 2026

- Daytime high temperatures in the mid-to-upper 90s and lower 100s, overnight lows in the upper 70s and lower 80s as well as afternoon heat indices of around 100-110 F continue.

- Breezy onshore winds (gusts to 25-30 mph) return later in the week, building moisture content and increasing heat risks from minor and moderate (levels 1 and 2 of 4) to mainly moderate by Friday.

- Daily low (15-20%) chances of afternoon showers and thunderstorms along the daytime seabreeze could increase slightly to a low (20-30%) chance on Friday and Saturday. - A low risk of rip currents prevails through Tuesday afternoon.

DISCUSSION

Issued at 1036 PM CDT Mon Jul 6 2026

Influence from being on the edge of both a weak inverted trough and high pressure aloft over Mexico and the eastern Gulf, respectively, combined with near to slightly above average moisture content, yet weaker onshore southeasterly flow, leave for a bit of uncertainty in coverage and probability of isolated to potentially scattered showers and thunderstorms across deep south Texas along the afternoon seabreeze over the next three days. Though, for now, have left a low (15-20%) chance of rain each afternoon Tuesday through Thursday, mostly residing along and east of US-281/I-69 C.

Wednesday night, a pressure gradient begins to tighten, causing lower level southeasterly winds to increase afternoon gusts to 25-30 mph, amplifying moisture advection inland off of a plume of deep and tropical moisture extending into the Bay of Campeche and the western Gulf; the 18Z deterministic GFS indicates PWAT values increasing substantially Thursday and into the weekend to potentially as high as 2.0-2.4 in. by Saturday. Given slight deepening of weak troughing aloft and above average moisture content, chances of rain remain relatively low, at most a 20-30% chance on Friday and Saturday, all showers and thunderstorms have the potential to produce periods of heavy rain over the later half of this week. At this time, the most widespread chances of rain appear to fall on Friday, but details will become clearer over the next several days. Chances and coverage of rain could begin to wane later in the weekend and into the beginning of next week as a strong high pressure aloft shifts from the western US to the Plains.

Otherwise, high temperatures are expected to ease slightly as clouds build, decreasing by a few degrees from mainly upper 90s inland (lower 100s across portions of the Rio Grande Plains) to mid/upper 90s by Thursday, while heat indices continue to maximize around 100-110 F. Factoring in increasing relative humidity, minor to moderate heat risks are anticipated to escalate to mostly moderate by Friday. Highs in the mid 80s prevail along/near the coast. Overnight lows in the mid/upper 70s inland and lower 80s along/near the coast persist.

A low risk of life-threatening rip currents continues through Tuesday afternoon.

AVIATION

(12Z TAFS) Issued at 522 AM CDT Tue Jul 7 2026

Light southeast winds with mostly clear skies prevail across Deep South Texas early this morning. Light winds will increase and become gusty later this morning into the afternoon. Winds will decrease later this evening. VFR conditions are expected for the next 24 hours.

MARINE

Issued at 1036 PM CDT Mon Jul 6 2026

A tightening pressure gradient increases gentle to moderate, fresh at times, southeasterly winds and slight to moderate (1-3 ft) seas to mainly moderate to fresh with moderate (3-5 ft) seas by Wednesday, when ongoing periods of Small Craft Exercise Caution conditions become more likely. A low (15-30%) chance of rain Tuesday and Wednesday increases to a low to medium (20-40%) chance Thursday and Friday, followed by gradually lowering chances Saturday into the beginning of next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 94 80 94 79 / 20 10 10 10 HARLINGEN 96 76 96 76 / 20 10 20 0 MCALLEN 99 79 99 78 / 10 10 10 0 RIO GRANDE CITY 100 77 99 76 / 10 10 10 0 SOUTH PADRE ISLAND 88 81 88 81 / 10 10 10 0 BAYVIEW/PORT ISABEL 93 78 92 78 / 10 0 10 0

BRO WATCHES/WARNINGS/ADVISORIES

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