textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1227 AM CDT Sun May 31 2026

* Seasonably hot temperatures and dry conditions continue through the remainder of this weekend, with highs in the low/mid 90s and a mostly minor heat risk (level 1 of 4) as afternoon heat indices range from the upper 90s to lower 100s.

* Building moisture and abundant sunshine further elevate apparent temperatures to around 100-105 F early next week, resulting in a minor to moderate (level 2 of 4) heat risk on Monday.

* Clouds build and at least a daily low (15-30%) chance of rain arrives by late Monday afternoon, building to as much as a low to medium (20-50%) Tuesday into Thursday, which should help to temporarily cool temperatures and heat indices.

* Chances of rain gradually decrease later next week, thus warming temperatures and building heat risks again into next weekend.

* Low risks of rip currents are anticipated to steadily increase to a medium or a high risk throughout next week.

DISCUSSION

Issued at 1026 PM CDT Sat May 30 2026

Not too much has changed for the 7 day forecast across deep south Texas. High pressure aloft maintains control for the next couple of days, resulting in mainly dry conditions through this weekend and near-normal temperatures, maximizing in the low/mid 90s into the early parts of next week. Throughout this weekend, a mostly minor heat risk is anticipated across the CWA, with heat indices ranging from 95-100 F over the Northern Ranchlands and the Rio Grande Plains while peaking in the lower 100s across the RGV and coastal plains, where some areas could experience a moderate heat risk. Meanwhile, a persistent area of weak low pressure over the Bay of Campeche maintains a steady stream of deep moisture into our region via southeasterly to easterly winds, significantly increasing lower level moisture content, with PWAT values surpassing 2.0 in. next Monday and Tuesday. As moisture builds, heat indices are likely to increase by a few degrees on Monday, with a minor to moderate heat risk across all of deep south Texas as apparent temperatures top out around 100-105 F, possibly warmer in a few spots in the RGV.

Lift and winds over the Gulf enhance and shift from southeasterly to easterly early next week ahead of a frontal boundary stalling across the coastal Deep South while 500 mb heights and subsidence aloft slowly decline. Beginning later Monday afternoon, pulses of Gulf moisture are expected to bring at least a daily low (15-30%) chance of showers and thunderstorms, peaking in convective coverage and activity in the afternoon during maximum diurnal instability, with the best chances along/east US-281. PoPs could rise to as much as a low to medium (20-50%) chance Tuesday into Thursday afternoon. Increased cloud coverage should help knock down temperatures, heat indices and heat risks by Tuesday, with highs in the upper 80s/low 90s and a mostly minor heat risk. Overnight lows continue to fall to the 70s along with a low (15-30%) chance of rain. However, high pressure may begin to build aloft again by next weekend, thus warming temperatures and re- escalating heat risks as chances of rain lower and cloud cover begins to clear.

A low risk of rip currents continues through Sunday afternoon. Rip current risks are currently expected to gradually enhance to a medium or high risk throughout next week as an easterly fetch enhances wave heights and lengthens wave periods over the Gulf.

AVIATION

(06Z TAFS) Issued at 1227 AM CDT Sun May 31 2026

MVFR to VFR will prevail at the aerodromes through the next 24 hours, with light to moderate winds and increasing cloudiness.

MARINE

Issued at 1026 PM CDT Sat May 30 2026

Gentle to moderate southeasterly to easterly winds continue throughout the forecast period, resulting in slight to moderate (2-4 feet) seas through at least the early or middle part of next week. Later in the week, a pressure gradient developing over the Gulf could increase seas just a bit, resulting in more moderate (4-6 feet) seas into next weekend. There is a slight chance of rain over the weekend, but daily rounds of showers and a few thunderstorms bring at least a low (15-30%) chance of rain beginning and increasing to as much as a low to medium (30-60%) chance on Tuesday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 92 79 92 79 / 0 0 20 10 HARLINGEN 92 76 91 75 / 0 0 20 10 MCALLEN 96 79 95 78 / 0 0 20 10 RIO GRANDE CITY 96 77 96 77 / 0 0 0 0 SOUTH PADRE ISLAND 86 82 85 81 / 0 0 20 10 BAYVIEW/PORT ISABEL 89 79 89 78 / 0 0 10 10

BRO WATCHES/WARNINGS/ADVISORIES

None.