textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1239 AM CDT Sat May 23 2026

Key Messages:

- A Flood Watch is in effect until Monday morning. There is a chance of isolated to scattered flash flooding in areas that receive heavier rainfall on Saturday and Sunday.

- The Storm Prediction Center as all of Deep South Texas under a Marginal Risk (level 1 of 5) for severe weather. - A moderate risk of rip currents continues through Saturday afternoon.

DISCUSSION

Issued at 1055 PM CDT Fri May 22 2026

The active weather pattern is forecast to continue through the weekend. Widespread showers and thunderstorms are likely across Deep South Texas Saturday. An upper level shortwave traversing South Texas will increase forcing across the area, combining with a deep moisture profile and CAPE values above 3000 J/kg resulting in an environment favorable for heavy rainfall, and isolated strong to severe thunderstorms. Observed PWAT value of 1.8 inches from the 0z Brownsville sounding approaches the 90th percentile value of 1.84 inches. A flood watch remain in effect through Monday morning and the Weather Prediction Center has a slight risk (level 2 of 4) for excessive rainfall for all of Deep South Texas Saturday. Additionally, the Storm prediction Center has Deep South Texas under a marginal (level 1 of 5) risk for severe weather.

Showers an thunderstorms will likely continue Sunday with PoPs around 40-60% along the coast decreasing to around 15-20% over western portions of the CWA. Rain chances fall to around 20-30% Monday and Tuesday, before another upper level trough increases rain chances to 40-50% Tuesday night into Wednesday.

AVIATION

(06Z TAFS) Issued at 1239 AM CDT Sat May 23 2026

Mid and high level clouds from fading convection over Mexico prevail across Deep South Texas early this morning. Mainly VFR conditions are forecast through the next 24 hours. However, there is a low to medium probability of MVFR ceilings overnight to around sunrise. Also, brief periods of MVFR/IFR will be possible in and around any convection that occurs later today. Widespread showers and thunderstorms will likely to impact the terminals later this morning into the afternoon. However, the timing of the convection remains low.

MARINE

Issued at 1055 PM CDT Fri May 22 2026

Generally favorable winds and seas are forecast to continue through the forecast, however daily showers and thunderstorms will be possible through the middle of next week. Saturday and Sunday will likely feature the highest chances for showers and thunderstorms, with chances around 60-70%. These storms could produce heavy rainfall, frequent lightning, strong winds, and locally higher seas. Otherwise, generally light to moderate southeasterly to easterly winds and slight to moderate seas are forecast to persist.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 91 77 90 75 / 60 50 70 10 HARLINGEN 90 73 88 72 / 70 50 60 20 MCALLEN 90 75 90 75 / 80 40 40 30 RIO GRANDE CITY 89 72 90 73 / 60 30 20 40 SOUTH PADRE ISLAND 85 79 84 78 / 50 40 60 20 BAYVIEW/PORT ISABEL 89 76 88 75 / 60 50 60 20

BRO WATCHES/WARNINGS/ADVISORIES

TX...Flood Watch through Monday morning for TXZ248>255-351-353>355- 451-454-455.

GM...None.