653
FXUS64 KBRO 041146 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
546 AM CST Thu Dec 4 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 533 AM CST Thu Dec 4 2025

* A cool fropa will result in scattered showers and maybe a
  thundershower during the day on Thursday along with falling
  temperatures; best chances near the coast and over the Gulf Waters.

* Lingering post-frontal, stratiform showers are expected to persist
  through Friday.

* Fluctuating (roller-coaster) temperature regime expected through
  next week.

* Small Craft Advisory is in effect from 5 PM CST Thursday to Noon
  CST Friday in response to the cool fropa.

&&

.DISCUSSION...
Issued at 1035 PM CST Wed Dec 3 2025

The forecast period will consist of unsettled weather conditions
initially (Thursday through Friday) followed by rain-free weather
through the remainder of the period. Cloud coverage will range
between mostly cloudy to partly cloudy with mostly cloudy skies
early in the period and partly cloudy skies developing next week.
A fluctuating temperature pattern will also take place, though
temperature anomalies will overall run near normal levels for the
balance of the forecast period.

Latest satellite and MSAS sfc observations depicted the eastern
half of Texas socked under a scattered to overcast deck of stratus
to strato-cumulus clouds with some areas of fog with a nearby
frontal boundary and weak shortwave trough over Deep South Texas.
Here across Deep South Texas, particularly over the mid to lower
Rio Grande Valley, there is a lull in cloud coverage. However,
satellite trends are suggesting that clouds will begin to increase
over these areas over the next 3-6 hours. Dewpoint depressions
are low as well ranging between 2-4 at the local terminals, so may
have to watch for the potential for mist/fog later. Expect a
quiet night ahead with at least periods of clouds and maybe some
mist as the frontal boundary remains to our north.

During the late morning to early afternoon hours, the aforementioned
frontal boundary to our north will pass to our south as a cool front.
Showers and maybe a few thunderstorms are expected to develop late
morning and especially during the afternoon hours on Thursday in
response to this frontal boundary. High temperatures (lower 80s
along the Rio Grande Valley; 70s elsewhere) will likely be reached
during the early afternoon hours as temperatures will fall throughout
the remainder of the day. As cold air advection (CAA) on northerly
winds continues to build into the region, overnight low temperatures
will fall to below normal levels with values in the 50s along the
RGV and coastal area, and 40s over the Northern Ranchlands. Lingering
post-frontal stratiform type rain showers will take place on Friday.
High temperatures will struggle to make it out of the 60s across
the region on Friday due to rain chances and abundant cloud cover.
Overnight low temperatures Friday night will be near seasonable
levels with values in the 50s areawide with any lingering rain
showers ending.

Rainf-free or tranquil weather conditions returns Saturday and will
persist through the remainder of the forecast period or through
next Thursday. Cloud coverage is expected to improve in time as
well transitioning from mostly cloudy to partly cloudy. A warming
trend takes place Saturday and Sunday before cooling down again on
Monday and finally warming up again Tuesday through Thursday.

&&

.AVIATION...
(12Z TAFS)
Issued at 533 AM CST Thu Dec 4 2025

MVFR to VFR conditions will prevail at the aerodromes through the
next 24 hours due to the approach and passage of a cold front. The
latest HRRR model data does not indicate a robust chance of
precipitation for the TAF period, and therefore it has been
removed for this most recent TAF issuance.

&&

.MARINE...
Issued at 1035 PM CST Wed Dec 3 2025

Small Craft Advisory (SCA) conditions are expected to develop
Thursday afternoon through Thursday night in response to a cool
fropa. Marine conditions improve on Friday with low to moderate
winds and seas persisting into Sunday. Sunday night into Monday,
an enhanced pressure gradient will result in the potential for
adverse marine conditions developing. Marine conditions look to
improve once again Monday night through the remainder of the
forecast period or through Thursday with low to moderate winds and
seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             78  53  67  58 /  40  40  20  30
HARLINGEN               75  49  65  54 /  40  30  20  20
MCALLEN                 75  52  67  58 /  20  20  10  30
RIO GRANDE CITY         72  50  67  55 /  10  20  10  20
SOUTH PADRE ISLAND      75  59  69  66 /  60  60  30  40
BAYVIEW/PORT ISABEL     76  51  68  58 /  50  40  20  30

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk from this evening through Friday afternoon
     for TXZ451-454-455.

GM...Small Craft Advisory from 5 PM this afternoon to noon CST Friday
     for GMZ130-132-135-150-155-170-175.

&&

$$