280
FXUS64 KBRO 070507
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1107 PM CST Sat Dec 6 2025

...New KEY MESSAGES, DISCUSSION, AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1103 PM CST Sat Dec 6 2025

* Mist/fog (some perhaps dense in spots) is possible tonight into
  Sunday morning.

* Hazardous marine conditions are expected to develop Sunday evening
  through Monday in association with a cool/cold front.

* Adverse to hazardous marine conditions could develop once again
  Friday into next Sunday following the passage of a second cold
  front.

* Dry weather with fluctuating temperatures are expected through
  the upcoming workweek.

&&

.DISCUSSION...
Issued at 1103 PM CST Sat Dec 6 2025

A benign weather pattern with fluctuating temperatures is
expected through the forecast period or through next Sunday.

Through tonight and into Sunday morning, the first weather concern
will be the likelihood of fog development (possibly becoming dense
in spots). Dewpoint depressions are already low (3 degrees or less)
as of this update. The combination of light winds and copious
amounts of low level moisture trapped underneath a sharp inversion
around 850 mb, per this evening`s 00z BRO sounding, will support the
development of fog later this evening/tonight. Fog is expected to
become widespread and possibly dense in spots tonight into Sunday
morning. We`ll closely be monitoring trends on if a Dense Fog
Advisory will be needed tonight. Any fog that develops tonight is
expected to gradually scour or burn out Sunday morning. The timing
will depend on how strong the capping inversion above the sfc is.

Sunday through the upcoming workweek will be dry and quiet for the
most part. A couple of cool/cold fronts are expected to sweep
through Deep South Texas through the upcoming week. The first will
be in the Sunday night into Monday time frame. The second will be on
Friday. The passage of the front will lead to our second weather
concern, which is deteriorating marine/coastal conditions Sunday
evening through Monday (see MARINE SECTION for more details).

With a couple of cool fronts expected to push through the region
over the next week, temperatures are expected to fluctuate. High
temperatures on Sunday will be in the 80s. Following the cool fropa
Sunday night, Monday`s highs will be noticeably cooler with values
in the lower 70s along the RGV and 60s elsewhere. Tuesday, highs
rebound into the 70s across all of Deep South Texas and into the 80s
on both Wednesday and Thursday.

A second cold front arrives on Friday which will result in highs
only reaching the 70s across Deep South Texas. Additional cold air
advection (CAA) on Saturday will result in highs struggling to make
it out of the 60s most places. Finally, next Sunday, high
temperatures rebound into the 70s most places and 60s across Brush
Country. Overnight low temperatures for the most part will be in the
50s and 60s. Sunday night, Monday night, and then again Friday night
and Saturday night, lows will be in the 40s most places (50s along
the RGV).

&&

.AVIATION...
(06Z TAFS)
Issued at 1103 PM CST Sat Dec 6 2025

Through 06z Monday....The main weather concern to aviation operations
during the 06z TAF period is the likelihood of mist, fog, and/or
low stratus developing tonight. The latest satellite and sfc
observations showed a SCT-OVC deck of stratus clouds ranging
between 600-3,500 feet AGL. Flying conditions have been fluctuating
over the past few hours. Currently, MVFR conditions were taking
place at KBRO and KHRL. However, IFR conditions are taking place
over KMFE due to low ceilings. Visibilities are ranging between
5-8 statute miles due to mist/haze.

Due to the combination of light winds and copious amounts of low
level moisture trapped underneath a sharp inversion just above the
sfc, per this evening`s BRO Sounding, and narrowing dewpoint
depressions, low stratus, mist, or fog are expected to increase in
probability and coverage over the next few hours and persist into
Sunday morning.

Have maintained TEMPO groups for all the terminals to account for
the likelihood of fog/mist/low stratus developing tonight into
Sunday morning. Any fog/mist that develops will have the capabilities
of reducing cigs/vsbys to MVFR-LIFR levels through Sunday morning.
The likelihood of dense fog developing is increasing as well and
we could see extended period of LIFR-VLIFR conditions occur tonight
into Sunday morning.

Any fog/mist/low stratus that develops overnight is expected to
gradually scour or burn out by mid to late Sunday morning. Depending
on how strong the capping inversion is just above the sfc will
depend on how quickly the fog/mist will burn out. Eventually,
flying conditions will return to VFR-MVFR conditions on Sunday.

Light north-northeast winds 5-10 kts this evening will trend towards
light and variable to calm tonight.

&&

.MARINE...
Issued at 1103 PM CST Sat Dec 6 2025

Favorable marine conditions will persist into Sunday. However,
marine conditions are expected to rapidly deteriorate Sunday
evening into Sunday night in response to a cold frontal boundary
and an enhanced pressure gradient. A Small Craft Advisory has been
issued for the Laguna Madre and Gulf Waters from 6 PM CST Sunday
to 6 PM CST Monday as a result. Marine conditions become more
favorable with low to moderate seas returning Monday night into
Tuesday. These favorable marine conditions will persist through
Thursday/Thursday night. Friday into next Sunday, marine conditions
are expected to deteriorate once again with Small Craft Exercise
Caution (SCEC) to Small Craft Advisory (SCA) conditions developing.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             77  65  85  54 /  40  10  10   0
HARLINGEN               77  61  86  49 /  40  10   0   0
MCALLEN                 79  64  87  52 /  40  10   0   0
RIO GRANDE CITY         79  60  86  48 /  20   0   0   0
SOUTH PADRE ISLAND      74  66  77  60 /  40  10  10   0
BAYVIEW/PORT ISABEL     75  63  83  54 /  40  10   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory from 6 PM Sunday to 6 PM CST Monday for
     GMZ130-132-135-150-155-170-175.

&&

$$

SHORT TERM...23-Evbuoma
LONG TERM....23-Evbuoma
AVIATION...23-Evbuoma