textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1230 PM CDT Fri May 8 2026

Key Messages:

* There is a Marginal Risk (Level 1/5) of isolated severe thunderstorms and a Marginal Risk (Level 1/4) of isolated flash flooding through tonight across Zapata, Jim Hogg, Starr, and western Hidalgo counties.

* These risks are conditional, but if severe thunderstorms develop, there is at least a 5% probability of large (1+ inch) hail, damaging winds (60+ mph) and excessive rainfall.

* A moderate risk of rip currents continues into this weekend due to long period swell with minor tidal runup each afternoon across narrow beaches.

* Minor to Moderate (Levels 1/4 and 2/4) Heat Risks through the weekend.

DISCUSSION

Issued at 1230 PM CDT Fri May 8 2026

A mid-level trough gradually works eastward through Texas into Saturday, before the subtropical ridge begins to build from the west through mid next week. At the surface, the stalled frontal boundary along the lower Texas coast slowly begins to work further offshore on Saturday, dragging any remaining rain chances with it. The next front arrives late Sunday night into early Monday, with only a brief chance of rain along the boundary early Monday morning. Temperatures are expected to generally bump back above normal through the period, with near to slightly below normal temperatures behind the next front Monday into Tuesday. NBM temperatures may be too warm with the frontal boundary on Monday into Tuesday. Minor to Moderate (levels 1/4 and 2/4) Heat Risks are expected across Deep South Texas through the weekend.

As for tonight, most CAMs try to develop some sort of Sierra Madre convection this evening into tonight, with highly varying solutions both into and avoiding Deep South Texas. The best chance occurs across the brush country of Zapata, Jim Hogg, and into Starr or western Hidalgo counties starting between 7-10 PM and continuing into tonight, if it develops and can persist eastward. PWATs from the morning sounding at BRO were 2.07 inches, the daily max, with the 90th percentile at 1.75 inches, lending plenty of moisture to any showers or thunderstorms. Southern Starr County received 1-2 inches this morning in persistent slow-moving thunderstorms. Any activity this evening or tonight would be very similar, with a general 1-2 inches where anything can develop and locally higher amounts of 3-4 inches where any heavier showers or thunderstorms can persist over a couple of hours.

The severe weather threat remains isolated and marginal, again mainly across Zapata, Jim Hogg, Starr, and western Hidalgo counties due to the threat of large hail or damaging winds. Confidence in severe weather or flooding rainfall remains low to medium, with the most likely outcome being some beneficial rainfall this evening through tonight for a few lucky locations.

Astronomical tides have begun to diminish into the weekend with a few narrow beaches becoming more narrow near high tide this afternoon and again Saturday afternoon. No Coastal Flood Statements are needed at this time. There remains a moderate risk of life-threatening rip currents into this weekend with a persistent long-period swell.

AVIATION

(18Z TAFS) Issued at 1230 PM CDT Fri May 8 2026

MVFR conditions have held on a bit into this afternoon and are expected to briefly break to VFR before returning tonight. The chance of rain, including showers and thunderstorms remains higher west of MFE this evening through tonight and will be monitored. A few strong to severe thunderstorms with tall CB and large hail may be possible just west of the border this evening into tonight.

MARINE

Issued at 1230 PM CDT Fri May 8 2026

Southeasterly winds prevail through the weekend with the next frontal boundary arriving late Sunday night into Monday morning. This briefly elevates seas and winds, before more favorable marine conditions return late Monday through late week. There remains a chance of showers and thunderstorms into Saturday and with the frontal passage early Monday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 77 90 76 92 / 0 30 0 0 HARLINGEN 74 89 73 93 / 10 20 0 0 MCALLEN 76 90 75 95 / 20 20 0 0 RIO GRANDE CITY 74 89 74 94 / 50 30 10 0 SOUTH PADRE ISLAND 78 83 78 85 / 0 20 0 0 BAYVIEW/PORT ISABEL 76 88 76 90 / 0 20 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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