Alton, Texas Weather Forecast Discussion

487
FXUS64 KBRO 271114 AAB
AFDBRO
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
614 AM CDT Sat Sep 27 2025
...New AVIATION...
.DISCUSSION...
Issued at 1019 PM CDT Fri Sep 26 2025
Ridging aloft from a building high pressure over northeastern Mexico
is expected to keep dry conditions (less than 10% PoP`s) across most
of Deep South Texas and the Rio Grande Valley today through the
daytime tomorrow, outside of a low (15-20%) chance of rain for
southern portions of Cameron County tomorrow afternoon. Late
tomorrow night through Monday night, a low (15-30%) chance of
showers develops and continues across coastal areas in response to
weak mid-level disturbances passing over southern-central Texas,
expanding inland along the seabreeze boundary throughout Monday
afternoon, remaining mostly east of US-281/I-69 C, with the highest
PoP`s closer to the coast. Following, ridging aloft enhances again
as a mid-level high expands over northwestern Mexico, causing
probabilities of rain to decrease from a low (15-20%) chance on
Tuesday afternoon across portions of the lower Rio Grande Valley to
a less than 15% chance for Wednesday and Thursday. PoP`s look to
increase again later in the work week and into next weekend as a
trough over the eastern CONUS extends southwestward into the
Southern Plains, leading to 20-30% PoP`s along the afternoon
seabreeze on Friday and Saturday.
High temperatures are likely to remain near average, warming to
slightly above normal throughout the later part of this upcoming
week as ridging aloft decreases cloud coverage with inland highs
increasing from low/mid 90`s over the weekend to mid/upper 90`s by
Wednesday. Highs in the mid 80`s persist along the immediate
coast. Mostly minor (level 1 of 4) heat risks continue each day,
though pockets of moderate (level 2 of 4) heat risks are possible
across the upper Rio Grande Valley and the Rio Grande Plains on
Wednesday and Thursday. Average overnight lows are expected to
continue, falling to the upper 60`s/low 70`s inland and upper 70`s
along the immediate coast.
&&
.AVIATION...
(12Z TAFS)
Issued at 612 AM CDT Sat Sep 27 2025
VFR conditions are expected to prevail through the TAF period with
occasional ENE gusts this afternoon around 15 kts.
&&
.MARINE...
Issued at 1019 PM CDT Fri Sep 26 2025
Favorable marine conditions continue as gentle to moderate
northeasterly to easterly winds result in slight (1-2 feet) seas. A
low to medium (15-30%) chance of showers and thunderstorms returns
tomorrow, increasing to a low to medium (20-40%) late tomorrow night
through Monday night with additional chances possible throughout the
remainder of the forecast period.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             91  73  89  74 /  10  10  20  20
HARLINGEN               93  68  91  69 /   0   0  10  10
MCALLEN                 97  72  94  72 /   0   0  10  10
RIO GRANDE CITY         97  68  94  69 /   0   0   0   0
SOUTH PADRE ISLAND      87  78  86  79 /  10  10  20  20
BAYVIEW/PORT ISABEL     89  73  88  74 /   0  10  10  20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...65-Irish
LONG TERM....56-Hallman
AVIATION...56-Hallman

NWS BRO Office Area Forecast Discussion