918
FXUS64 KBRO 080335
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1035 PM CDT Tue Oct 7 2025

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Updated at 1028 PM CDT Tue Oct 7 2025

* Daily low to medium (20-60%) chances for isolated to scattered
  showers and thunderstorms are expected through Friday.

* Thursday will present a medium-high (30-70%) chance for showers
  and thunderstorms; highest chances along and east of IH-69C.

* Warmer than normal temperatures are expected to persist through
  early next week.

* Small Craft Exercise Caution (SCEC) conditions are possible late
  Wednesday night into Friday with wave heights between 4-6 ft.

&&

.DISCUSSION...
Issued at 1028 PM CDT Tue Oct 7 2025

The influx of moisture over the region coupled with a nearby weak
shortwave trough will continue to be the focus of day-to-day or near
day-to-day chances for isolated to scattered showers and thunderstorms
through Friday. The influx of moisture is evident over the region
this evening with precipitable water (PWAT) values of 1.90", per
this evening`s 00z BRO sounding. Through tonight, another round of
showers (isolated to widely scattered) are possible across Deep
South Texas and the Rio Grande valley as additional moisture is
seen streaming in from the Gulf via radar and satellite imagery
this evening. The best chance for any showers will be located
along the Rio Grande Valley and areas near the Lower Texas Coast.

Wednesday through Friday will be a rinse and repeat from
today/tonight as sfc convergence along the seabreeze, outflow
lift from nearby thunderstorms, and/or an adequate amount of sfc
based differential heating will serve as lifting mechanisms for
the initiation of showers and thunderstorms, particularly during
the daytime with isolated chances possible during the nighttime
hours. Any rain that develops could produce heavy downpours and
posing of roadways, but ultimately will prove to be beneficial
given the overall dry trends of late.

As far as probabilities, we continue to maintain a general low-
medium(20-60%) chance for showers and thunderstorms tonight through
Friday, with the best chance being anywhere from the late morning
to early evening hours and the greatest confidence/probabilities
being along and east of IH-69C. Wednesday and Thursday will be the
days where PoPs peak. That`s where we have a medium-high (30-70%)
chance for showers and thunderstorms with categorical PoPs being
located along the Rio Grande Valley, and along and east of IH-69C.

Temperature anomalies will continue to run warmer than normal for
this time of year, courtesy of a 588-591 dam heat ridge in place
overhead. This feature will generate daily daytime highs in the low
to mid 90s through early next week. Overnight lows will be in the
60s and 70s with 60s found across parts of the Northern Ranchlands
and occurring mainly late week into early next week (due to clearing
skies and increased radiational cooling).

&&

.AVIATION...
(00Z TAFS)
Issued at 637 PM CDT Tue Oct 7 2025

Through 00z Thursday....VFR to MVFR conditons are expected to be
in place through 00z Thursday. Isolated to scattered showers and
thunderstorms are expected to persist this evening through the day
on Wednesday. Showers and storms will come in waves through Wednesday.
Have VCSH and Prob30 groups to account for the potential for showers
and thunderstorms. Some of the heavier showers/storms could briefly
reduce cigs/vsbys to IFR levels.

East-northeast winds with speeds between 5-15 kts this evening are
expected to trend towards light and variable to calm tonight. East-
northeast winds will pick up again on Wednesday with speeds between
5-15 kts and gusts up to 20 kts or so, particularly during the
afternoon hours. Any thunderstorms that move over a TAF site will
have the capabilities of briefly producing variable winds with
gusts up to 35kts or so.

&&

.MARINE...
Issued at 1028 PM CDT Tue Oct 7 2025

Light to moderate winds and low to moderate seas are expected
through the forecast period. An enhanced pressure gradient will
result in 3-6 ft seas developing Wednesday-Wednesday night and
persisting through Saturday, before potentially decreasing to 2-4
ft Sunday through early next week. Small Craft Exercise Caution
(SCEC) conditions are possible late Wednesday night into Friday,
with wave heights between 4-6 ft. Finally, daily low to medium
(20-60%) rain chances in general are expected to persist through
Friday. Thursday will see medium-high (60-80%) chances. 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...23-Evbuoma
LONG TERM....23-Evbuoma
AVIATION...23-Evbuoma