353
FXUS64 KBRO 071735
AFDBRO

Area 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.

&&

.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.

&&

.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.

&&

.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.

&&

.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

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...22-Garcia
LONG TERM....22-Garcia
AVIATION...22-Garcia