326
FXUS64 KBRO 140345
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1045 PM CDT Wed Aug 13 2025

...New DISCUSSION, MARINE...

.DISCUSSION...
Issued at 1042 PM CDT Wed Aug 13 2025

Summertime heat will continue on Thursday with highs in the mid to
upper 90s east of I-69E to the triple digits along and west of the
I- 69E corridor. The combination of the heat and elevated humidity
will result in triple-digit heat index values on Thursday.

A broad low pressure area has formed along the tropical wave,
currently located over of the Yucatan Peninsula, and is expected to
track west-northwestward across the southwestern Gulf later tonight.
This system will continue to move towards the western Gulf coast
through Friday. The National Hurricane Center has a low chance (20%)
of development through the next 48 hours. Regardless of any tropical
development, this feature will bring an surge of tropical moisture
across much of the area early Friday morning into Saturday.

Model guidance continues to suggest precipitable water values
ranging from 2.2 to 2.4 inches along and east of US-281/I-69C by
Friday afternoon and remaining through Saturday afternoon. Both the
GFS/NAM12 indicate a pocket of 2.5+ inches moving northward along
the Lower Texas Coast Friday afternoon. Scattered showers and
isolated thunderstorms are expected to develop along the coast and
Gulf waters Friday morning before spreading further inland during
the late morning into the afternoon. The latest NBM probabilistic
guidance indicates forecast rainfall amounts between 0.1-0.5 inches.
Given the efficient rain-producing environment, locally heavy
rainfall upwards of 1 inch cannot be ruled out. This may result in
minor/nuisance flooding issues along low-lying or poor drainage
areas. High temperatures are expected to be few degrees lower Friday
and Saturday due to the increasing rain chances and cloud cover.

In addition, there will be an increased risk of rip currents and
increasing swell along the Lower Texas beaches Friday into Saturday
as the tropical wave/broad area of low pressure approaches the
western Gulf coast.

Conditions will begin to improve late in the weekend into early as
mid-level builds and provides subsidence across the region. Hot
conditions with mainly low rain chances will return through late
week.

&&

.AVIATION...
(00Z TAFS)
Issued at 634 PM CDT Wed Aug 13 2025

Mostly clear skies with moderate to gusty southeast winds prevail
across Deep South Texas early this evening. Winds will gradually
decrease through the evening hours and become light overnight.
Southeast winds increase again by late Thursday morning with some
gusts near 25 knots in the afternoon. VFR conditions are expected
for the next 24 hours.

&&

.MARINE...
Issued at 1042 PM CDT Wed Aug 13 2025

Favorable conditions will continue through Thursday with light to
moderate southeast winds and low to moderate seas. Slightly adverse
conditions with increasing wave heights, will develop Friday into
Saturday as a tropical wave approaches the region. Rain chances (30-
50%) will also be increasing Friday into Saturday with showers and
thunderstorms over the Gulf waters. More favorable conditions return
along the Lower Texas Coast late in the weekend into early next
week.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             98  80  97  80 /  10   0  10  10
HARLINGEN               99  76 100  77 /  20   0  10   0
MCALLEN                104  80 102  80 /  10   0   0   0
RIO GRANDE CITY        104  78 104  77 /  10  10   0   0
SOUTH PADRE ISLAND      89  82  90  82 /  10   0  10  10
BAYVIEW/PORT ISABEL     94  79  95  79 /  10   0  10  10

&&

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

$$

SHORT TERM...63-KC
LONG TERM....63-KC
AVIATION...63-KC