652
FXUS64 KBRO 271730
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1230 PM CDT Wed Aug 27 2025

...New DISCUSSION, AVIATION, MARINE...

.DISCUSSION...
Issued at 1230 PM CDT Wed Aug 27 2025

The latest radar and satellite imagery reveal generally rain free
conditions early this afternoon across Deep South Texas, with
only isolated showers over the Gulf waters and east of I-69E.
There should be a slight uptick in activity along the sea breeze
once again this afternoon as favorable moisture content and
diurnal instability interact with the boundary. However, the
GOES-19 Total Precipitable Water derived product estimates PWATs
ranging from 1.90-1.97 inches along and east of US-281, which is
lower than the past several days. This may result in more isolated
to widely scattered coverage for the afternoon and early evening
hours as the sea breeze pushes further inland. Similar to previous
days, the main threats with any development are gusty winds,
lightning, and locally heavy rainfall.

Precipitation chances should come to an end through the first
half of Labor Day weekend as subsidence associated with mid level
ridging centered over Central Texas builds over Deep South Texas.
While an isolated shower or thunderstorm cannot be ruled out,
chances are less than 10%. Our main weather concern will shift to
summer heat, especially as low level southeasterly winds keep dew
points/humidity elevated. Afternoon high temperatures are expected
to be near to slightly above normal for late August, with highs
ranging from the mid 90s along the immediate coast to around 105
degrees across the Rio Grande Plains. In combination with the
humidity, heat index values are expected to range from 100-110
degrees each afternoon. Given many of us will likely be enjoying
outdoor activities through the holiday weekend, it is important to
practice heat safety, including staying hydrated and taking
breaks in the shade, to prevent heat-related illnesses.

For Sunday into early next week, deterministic and ensemble
guidance suggest the aforementioned mid level ridge will shift
west, which will allow for a shortwave to translate along the
periphery of the ridge and approach the Texas Coast. Moisture
content is expected to increase in response to the shortwave,
resulting in precipitable water values upwards of 1.8-2.0 inches
by Sunday afternoon. This should allow for low to medium (20-40%)
precipitation chances Sunday afternoon through at least Tuesday,
as conditions should be favorable for diurnally-driven isolated to
scattered showers and thunderstorms.

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Wed Aug 27 2025

VFR and southerly to southeasterly winds will prevail through the
forecast period at all TAF sites. Limited sea breeze activity is
expected this afternoon, with the main threats from any convection
being gusty winds, brief heavy rainfall, lightning, and brief MVFR
ceilings/visibility. Otherwise, expect light and variable winds
tonight and mostly clear skies.

&&

.MARINE...
Issued at 1230 PM CDT Wed Aug 27 2025

Generally favorable marine conditions will prevail through next
week with light to moderate southeasterly winds and low seas as
mid level high pressure prevails. Low to medium (20-40%) rain
chances return Sunday into early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             79  94  79  95 /  10  10   0   0
HARLINGEN               76  97  75  98 /   0  10   0   0
MCALLEN                 79 100  79 102 /  10  10   0   0
RIO GRANDE CITY         77 102  77 104 /  10   0   0   0
SOUTH PADRE ISLAND      83  89  82  89 /  10  10   0   0
BAYVIEW/PORT ISABEL     78  93  78  93 /   0  10   0   0

&&

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

$$

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