textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 551 PM CDT Sun Sep 20 2026

- Daily low medium chances of rain return Monday and become region-wide by next Tuesday.

- Temperatures remain warm but ease off a few degrees from widespread areas of low 100s along/west I-69 E to mostly upper 90s by Tuesday.

- Extreme risks of heat-related illnesses (level 4/4) are likely to continue for more populated portions of the RGV/Rio Grande Plains through at least Tuesday while the rest of the region experiences moderate to major risks (level 2/4 and 3/4).

- A moderate risk of life-threatening rip currents continues through tonight.

DISCUSSION

Issued at 1206 PM CDT Sun Sep 20 2026

Quiet conditions expected today before a somewhat active weather pattern takes hold early week.

Deeper moisture begins to move into South Texas and rain chances will increase early week as the high pressure overhead weakens a bit and a frontal boundary pushes into central Texas. Low rain chances are expected in the low to mid-valley on Monday but become more widespread and increase to 30-60% on Tuesday. Rain chances up to 50% linger into late week. The bulk of any shower or thunderstorm activity will primarily coincide with peak daytime heating.

Heat Risk will remain Moderate to Extreme over the next week, though increased cloud cover and/or showers and thunderstorms could bring a little relief. Extreme heat risk is primarily expected in more urban/populated areas. Temperatures will still remain above normal with mid to upper 90s to low triple digits, though by Thursday and Friday, could struggle to reach the triple digits with the excess cloudcover and rain chances. Heat indices will peak each afternoon between 105-110 degrees.

There is a moderate risk of rip currents at area beaches. The strongest and most life threatening rips currents often occur near jetties and piers. Use caution if entering the water.

AVIATION

(00Z TAFS) Issued at 551 PM CDT Sun Sep 20 2026

VFR will prevail at the aerodromes through the next 24 hours, with light to moderate winds with breezy gusts and clear to partly cloudy skies. Convection is possible, but will be too isolated to warrant a mention in the current issuance of TAFs.

MARINE

Issued at 1206 PM CDT Sun Sep 20 2026

Generally favorable conditions will prevail with light to moderate southeasterly winds with seas around 2-3 ft and 5-6 second periods. Daily chances of showers and thunderstorms could lead to locally enhanced winds and seas.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 97 80 95 / 0 20 0 40 HARLINGEN 76 99 75 98 / 0 10 0 40 MCALLEN 80 103 79 100 / 0 20 0 60 RIO GRANDE CITY 78 102 77 100 / 0 10 10 40 SOUTH PADRE ISLAND 82 89 82 89 / 0 10 10 30 BAYVIEW/PORT ISABEL 79 95 79 94 / 0 10 10 30

BRO WATCHES/WARNINGS/ADVISORIES

None.