252
FXUS64 KBRO 291724 CCA
AFDBRO

Area Forecast Discussion...CORRECTED
National Weather Service Brownsville TX
1224 PM CDT Fri Aug 29 2025

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

.KEY MESSAGES...
Updated at 1206 PM CDT Fri Aug 29 2025

 - Moderate to major heat risks (levels 2 and 3 of 4) continue
   across all of deep south Texas through Sunday as daily
   afternoon heat indices reach 105-110 degrees F, with some
   locations experiencing indices of up to 112 degrees F for brief
   periods of time. Visit weather.gov/heatsafety for more
   resources.

 - The Weather Prediction Center (WPC) has included the
   northernmost portions of Brooks and Kenedy counties within a
   Marginal Risk (level 1 of 4) of excessive rainfall on Sunday as
   well as the northern half of Zapata, Jim Hogg, Brooks and
   Kenedy counties on Monday.

&&

.DISCUSSION...
Issued at 1206 PM CDT Fri Aug 29 2025

Dangerous heat continues to be the main focus for all of deep south
Texas through Sunday, thanks to a mid-level high pressure persisting
over the region, extending from the Desert Southwest to the Gulf,
which is providing subsidence and maintaining mostly sunny skies
with very low (less than 10%) chances of rain through Saturday.
Although air temperatures are expected to remain near to above
average, moderate southeasterly winds continue to advect moist Gulf
air inland, resulting in moderate to major (levels 2 and 3 of 4)
heat risks as afternoon heat indices reach 105-110 degrees F for a
few hours, with a few locations potentially experiencing indices up
to 112 degrees for brief periods of time. Like today, Special
Weather Statements (SPS`s) are possible again for all, or portions,
of deep south Texas, except for the barrier islands, on Saturday and
Sunday. The hottest indices are likely to be felt across portions of
the coastal counties and the Rio Grande Valley.

Meanwhile, amplification of the jet stream over the Rockies and
Plains throughout the weekend is expected to gradually push a
stationary boundary southward into southern Texas, gradually
enhancing surface convergence and upper level forcing from north to
south into the beginning of next week; probabilities of rain
increase from a low (15-20%) chance along the seabreeze on Sunday to
a medium (40-60%) chance by Monday afternoon, persisting overnight
into Tuesday and further elevating to a medium to likely (60-70%)
chance Tuesday afternoon and evening, before pushing through all of
the CWA by Wednesday morning. As the boundary approaches,
moisture pooling will aid in elevating PWAT`s to at least 2.0
inches by Monday evening, increasing into Tuesday. As these
ingredients interact with the high levels of instability already
in place, slow-moving convection producing heavy rainfall (in
addition to lightning and gusty winds) is expected and WPC has
included the northernmost portions of Brooks and Kenedy counties
within a Marginal Risk (level 1 of 4) of excessive rainfall on
Sunday as well as the northern half of Zapata, Jim Hogg, Brooks
and Kenedy counties on Monday due to the possibility of isolated
instances of minor flooding.

Following, PWAT`s decrease substantially throughout Tuesday night
and Wednesday, diminishing probabilities of rain to a low (15-30%)
chance along the seabreeze each afternoon from Wednesday through
Friday, expanding in coverage from southern portions of the Rio
Grande Valley on Wednesday to the northern ranchlands by Friday as
southeasterly return flow arrives and lifts the boundary
northward. Temperatures gradually cool to average by next Tuesday
along with mostly minor (level 1 of 4) heat risks into Friday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1206 PM CDT Fri Aug 29 2025

Mostly clear skies and VFR conditions continue over the next 24
hours with moderate (10-15 knots, gusting to around 20 knots)
southeasterly to southerly winds this afternoon diminishing to
light to gentle overnight tonight and back to moderate by
Saturday afternoon.

&&

.MARINE...
Issued at 1206 PM CDT Fri Aug 29 2025

Favorable marine conditions continue as mainly light to gentle
(moderate in the afternoons) southeasterly winds and slight (1-2
feet) seas prevail. Chances of showers and thunderstorms increase
to a medium to likely (30-60%) chance Monday into Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             80  96  79  95 /   0   0   0  10
HARLINGEN               76  99  76  98 /   0   0   0  10
MCALLEN                 80 102  79 102 /   0   0   0  10
RIO GRANDE CITY         77 104  77 103 /   0   0   0  10
SOUTH PADRE ISLAND      82  89  82  89 /   0   0   0  10
BAYVIEW/PORT ISABEL     78  94  79  94 /   0   0   0  10

&&

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

$$

SHORT TERM...65-Irish
LONG TERM....65-Irish
AVIATION...65-Irish