textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 623 PM CDT Wed Apr 29 2026

Key Messages:

- Next best chance for rainfall is Friday night ahead of a cold front.

- Cold front expected to bring cooler temperatures for a short time before temperatures rebound to above average by this time next week.

DISCUSSION

Issued at 1230 PM CDT Wed Apr 29 2026

Once again, not too much as changed with the forecast for the next week. The Storm Prediction Center has a very small portion of Northern Zapata in a general thunderstorm outlook. This is likely due to the potential for storms to develop over the Sierra Madre and then move into the region. However the Convection Allowing Models (CAM) have been rather mixed on this situation. With some showing a thunderstorm or a shower making it in to some not showing anything at all. Given the current environment at this time, the current forecast is not expecting much in the potential for rainfall tonight.

The main focus for tomorrow will be the heat as the high temperatures are expected to be in the upper 90 and triple digits. As such the heat risk for tomorrow is mostly moderate (level 2 of 4), with small portions of minor (level 1 of 4) and just a bit of major (level 3 of 4). It is important practice heat safety in these conditions so limit time outdoors and make sure to drink plenty of water.

However, with an approaching cold front and a mid-level shortwave in the atmosphere to help that cold front push through Deep South Texas and the Rio Grande Valley, there could be low to medium (30-40%) for rain on Friday night. This cold front is expected to bring a good change in the temperatures for about a day as the high temperatures on Saturday will be in the mid 70s. However, this cool down will not last long as the heat returns by Sunday with temperatures climbing back up again and by the end of the forecast period the highs could be back into the upper 90s. This front will at least provide a bit of relief from the heat and hopefully a little bit of rain as well.

AVIATION

(00Z TAFS) Issued at 623 PM CDT Wed Apr 29 2026

Through 00z Friday.....VFR-MVFR conditions are expected to persist through the 00z TAF period. MVFR cigs will be more prevalent during the night hours into the morning hours.

Winds will continue out of the southeast with speeds between 8-15 kts through the 00z TAF period. Winds will gusts as high as 20-25 kts during the afternoon hours.

MARINE

Issued at 1230 PM CDT Wed Apr 29 2026

While a good part of the forecast period will be generally favorable, this weekend looks to be rather active. A cold front is forecasted to move through the Lower Texas coast on Friday night and in its wake cause adverse to hazardous marine conditions and ahead of the front could see some showers and thunderstorms as well. With winds around 25 knots and seas around 8 to 9 feet possible for most of the weekend, Small Craft Advisory seems to be likely needed for much of the weekend. However, favorable conditions are expected to return by the start of next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 76 90 75 92 / 0 0 0 10 HARLINGEN 73 92 73 95 / 0 0 0 10 MCALLEN 76 95 77 96 / 0 0 0 10 RIO GRANDE CITY 74 95 74 95 / 10 0 0 10 SOUTH PADRE ISLAND 76 82 76 83 / 0 0 0 10 BAYVIEW/PORT ISABEL 74 88 74 89 / 0 0 0 10

BRO WATCHES/WARNINGS/ADVISORIES

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