353 FXUS64 KBRO 071735 AFDBROArea Forecast Discussion National Weather Service Brownsville TX 1235 PM CDT Tue Oct 7 2025
...New DISCUSSION, AVIATION, MARINE...
.KEY MESSAGES... Updated at 1235 PM CDT Tue Oct 7 2025
- Low to medium (20-60%) chances for isolated to scattered showers and thunderstorms through Friday.
- Highest rain chances are on Thursday, with medium to high (40-70%) chances across most of the Rio Grande Valley and immediate coast.
- Coastal Flood Statement remains in effect through this evening along the Lower Texas Coast beaches.
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.DISCUSSION... Issued at 1235 PM CDT Tue Oct 7 2025
A somewhat unsettled weather pattern is expected through the end of the week across Deep South Texas, with daily chances for isolated to scattered showers and thunderstorms. An influx of tropical moisture, aided by persistent easterly flow, will maintain elevated precipitable water values across the Rio Grande Valley and the immediate coast. However, subsidence associated with a building mid level ridge across the state of Texas will result in a notable airmass gradient across the Northern Ranchlands, with more limited moisture content. As a result, the highest precipitation chances each day will reside across most of the Rio Grande Valley and immediate coast, which coincides with the axis of highest precipitable water values.
This mornings 12Z sounding observed a precipitable water value of 1.85 inches, which is just above the 75th percentile for this time of year. Deterministic and ensemble guidance indicate precipitable water values ranging from 1.8 inches to upwards of 2.0 inches through the end of the week. In combination with daytime heating and the sea breeze, isolated to scattered showers and thunderstorms may develop from late morning into the early evening hours. Some activity may develop overnight as well given the unsettled airmass, particularly over the Gulf waters and immediate coast. Showers and thunderstorms will be capable of locally heavy rainfall, and while this will be beneficial given recent dry trends, may result in nuisance flooding issues across flood-prone areas and ponding on roadways. Precipitation chances come to an end by the weekend as subsidence builds overhead.
Otherwise, expect near to slightly above normal temperatures for early October. Increased cloud cover associated with showers and thunderstorms may temper the heat for a few hours each afternoon. A minor (level 1 of 4) to moderate (level 2 of 4) heat risk will continue due to the combination of slightly above normal temperatures and increasing humidity.
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.AVIATION... (18Z TAFS) Issued at 1235 PM CDT Tue Oct 7 2025
VFR will generally prevail through the forecast period at all TAF sites. However, isolated to scattered convection may result in brief MVFR ceilings/visibility. Additionally, brief heavy rainfall, gusty winds, and lightning cannot be ruled out. Given the isolated to scattered coverage, a PROB30 will continue for this afternoon. Opted to include VCSH for tomorrow morning, but adjustments in subsequent TAFs may be needed as high res guidance captures trends.
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.MARINE... Issued at 1235 PM CDT Tue Oct 7 2025
Low to moderate seas and light to moderate winds will prevail through the forecast period. Seas are expected to increase to around 3-5 feet by Thursday and continuing through at least the first half of the weekend. Otherwise, expect daily low to medium (20-60%) rain chances through the week, with low (20% or less) rain chances through the weekend. Locally enhanced winds and seas are likely within any showers or thunderstorms.
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.PRELIMINARY POINT TEMPS/POPS... BROWNSVILLE 77 90 77 89 / 60 50 50 70 HARLINGEN 74 90 73 90 / 40 50 30 70 MCALLEN 76 93 76 93 / 40 50 30 60 RIO GRANDE CITY 73 94 71 93 / 30 40 20 40 SOUTH PADRE ISLAND 80 87 81 86 / 60 60 50 70 BAYVIEW/PORT ISABEL 76 88 76 88 / 50 50 40 70
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.BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. &&
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SHORT TERM...22-Garcia LONG TERM....22-Garcia AVIATION...22-Garcia
NWS BRO Office Area Forecast Discussion