423 FXUS64 KBRO 192324 AFDBROArea Forecast Discussion National Weather Service Brownsville TX 624 PM CDT Fri Sep 19 2025
...New AVIATION...
.DISCUSSION... Issued at 1223 PM CDT Fri Sep 19 2025
Ample tropical moisture, along with diurnal heating and sea breeze activity will continue to support shower and thunderstorm activity for Deep South Texas and the Rio Grande Valley throughout this weekend and next week. Chances will be between 40-50% for areas east of US 281/I-69C between now and Sunday, and around 20-30% for areas west of US 281/I- 69C during the same timeframe. Early afternoons are the most favorable time of day for shower and thunderstorm development as daytime heating increases and the sea breeze advances westward, creating enhanced lift for convective initiation. On Monday and Tuesday, rain chances decrease to 20-30%, mainly only for areas east of I-69C, with the potential for increasing chances again on Wednesday and beyond.
High temperatures are expected to be in the low to mid 90s through the weekend, gradually warming into the mid to upper 90s throughout next week. Some areas in the Western Ranchlands could see temperatures in the triple digits by mid-week next week. Minor (level 1 of 4) Heat Risk is expected throughout Deep South Texas over the weekend, but this is expected to gradually increase to predominantly Moderate (level 2 of 4) and Major (level 3 of 4) by mid-week, with the highest Heat Risk expected on Wednesday. Low temperatures should generally be in the mid to upper 70s, with a few of the Western counties seeing low temperatures in the lower 70s. Partly cloudy and light to moderate east-southeasterly winds are expected throughout the forecast period.
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.AVIATION... (00Z TAFS) Issued at 616 PM CDT Fri Sep 19 2025
For the most part, convective activity has diminished this evening, though there continues to be showers popping up southwest of KHRL, which may continue over the next hour or so, bringing brief periods of moderate to heavy rain, before clearing up. VFR conditions continue overnight and through tomorrow aside from the possibility of morning showers at KBRO and again in the afternoon across all terminals as showers and thunderstorms develop, bringing additional rounds of lightning, gusty winds and heavy rain, possibly reducing visibility and lowering ceilings as noted within the PROB30`s. Gentle easterly winds of around 5-10 knots continue, though becoming light and variable overnight tonight.
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.MARINE... Issued at 1223 PM CDT Fri Sep 19 2025
Light to moderate east-southeasterly winds are expected for the forecast period and should remain below SCEC conditions. In addition, wave heights are expected to be between 2-3 feet. Therefore, overall favorable marine conditions are expected for the next seven days. Conditions could briefly deteriorate in the immediate vicinity of any thunderstorms that happen to form offshore.
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.PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 76 91 77 92 / 30 60 30 50 HARLINGEN 73 93 73 94 / 10 50 10 50 MCALLEN 76 95 77 96 / 10 40 10 30 RIO GRANDE CITY 73 96 74 97 / 10 30 0 10 SOUTH PADRE ISLAND 81 87 81 88 / 40 50 50 60 BAYVIEW/PORT ISABEL 76 89 77 91 / 20 50 30 50
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.BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. &&
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SHORT TERM...55-MM LONG TERM....55-MM AVIATION...65-Irish
NWS BRO Office Area Forecast Discussion