862
FXUS64 KBRO 140927
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
327 AM CST Tue Jan 14 2025

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Today through Wednesday)
Issued at 320 AM CST Tue Jan 14 2025

The KBRO Doppler radar shows very light rain and drizzle
spreading northwest into Deep South Texas and the Rio Grande
Valley from the adjacent coastal waters. However, local ASOS and
AWOS platforms are not registering any precipitation, and this may
be due to the fact that the most recent KBRO upper air sounding
indicated only .77 inches of precipitable water in the atmospheric
column, with significant dry air above 3700 feet.

Overall, the chance of rain will increase across the BRO CWFA during
the period, as inverted surface troughiness develops and strengthens
along the Lower Texas Coast, subsequently developing into a closed
area of low pressure. The best opportunity for rainfall appears to
be late tonight and into Wednesday morning, with the closed low
situated over the Laguna Madre.

Temperature-wise, the scattered to numerous patches of rainfall,
abundant cloud cover, and cold air advection of the back side of the
low will keep daytime high and overnight low temperatures in the
below normal range for this time of year.

Finally, elevated seas along the Lower Texas Coast will produce a
High Risk of rip currents at the local beaches through the entire
short term forecast period.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 320 AM CST Tue Jan 14 2025

There will be a lingering chance for precipitation tomorrow night as
the ongoing coastal low continues to bring moisture onshore (20-40%
chance east of I-69C). On Thursday an upper-level shortwave pushes
the coastal low off to the east and out of the area, which will
sharply decrease chances for any precipitation, though areas along
the coast could still see a shower or two. Conditions will be dry
Friday through the weekend, but skies will stay mostly cloudy and
winds will turn southerly.

A strong cold front is expected to pass through Deep South Texas
later Saturday into Sunday, bringing another round of arctic air
into the region. Current guidance is showing that this particular
system is taking on a McFarland shape, which is a notorious
troughing pattern for effectively bringing much colder air to the
Rio Grande Valley, with the potential for freezing low temperatures.
No precipitation is expected with the frontal passage itself, but
rain chances could return early next week in the wake of this cold
front, as another inverted coastal low may develop offshore.

Low temperatures for the next few nights will be in the upper
40s/lower 50s.  On Friday night, low temperatures will be a little
bit warmer, mainly in the mid-to-upper 50s. Once the front passes
through late on Saturday, low temperatures will be back down to the
mid 40s/lower 50s Saturday night, and will drop to the 30s
throughout Deep South Texas Sunday night and Monday night.  There is
the potential for freezing temperatures in the Northern Ranchlands
on both of these nights. The surge of arctic air will also
decrease sea surface temperatures to a cold enough level to pose
a hazard for sea turtle stunning.

High temperatures will be in the 60s Thursday, the 70s Friday, and
may even hit the lower 80s on Saturday before the cold front comes
through the area.  The front is expected to decrease high
temperatures to the upper 50s/lower 60s on Sunday, and the upper
40s/lower 50s on Monday. As guidance for the shaping of this
troughing pattern evolves, there is the possibility that post-
frontal temperatures could trend colder than current forecast
models are currently suggesting.

&&

.AVIATION...
(06Z TAFS)
Issued at 1050 PM CST Mon Jan 13 2025

VFR conditions gradually give way to MVFR ceilings and a chance of
rain working from east to west Tuesday. IFR conditions are
possible where any heavier or more persistent rain settles in,
especially BRO and HRL.

&&

.MARINE...
Issued at 320 AM CST Tue Jan 14 2025

(Today through Wednesday): Buoy 42020 reported northeast
winds around 16 knots gusting to around 19 knots with seas slightly
over 4.5 feet with a period of 7 seconds at 1:50 CST/07:50 UTC.
Small Craft Advisory conditions have not prevailed on the Gulf of
Mexico waters for the past several hours, and therefore, the
Advisory will be cancelled at this time. However, Advisory
conditions will develop tonight, and even more so on Wednesday, as
low pressure develops along the Lower Texas Coast and enhances the
pressure gradient.

(Wednesday Night through Monday)...Due to the presence of a
coastal low, sea heights will be elevated tomorrow night (between
5 and 8 feet), and Small Craft Advisories will likely be needed.
Winds are expected to be northerly. Marine conditions will become
more favorable Friday and Saturday as the coastal low moves out of
the area and the sea heights decrease to around 3-4 feet. Winds
will also turn to a more southerly direction. However, seas will
become elevated again as the next cold front comes through the
area by Sunday, changing the wind direction back to a northerly
direction and increasing speed and wave heights. Small Craft
Advisories will most certainly be needed after the frontal
passage, and the potential for gale conditions is not out of the
realm of possibility.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             65  56  61  51 /  50  60  50  40
HARLINGEN               63  53  58  47 /  50  70  60  30
MCALLEN                 59  53  58  50 /  50  70  40  30
RIO GRANDE CITY         57  50  56  49 /  50  60  40  20
SOUTH PADRE ISLAND      67  59  63  56 /  50  70  70  40
BAYVIEW/PORT ISABEL     67  55  62  50 /  40  60  60  40

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through Wednesday afternoon for TXZ451-454-
     455.

GM...None.
&&

$$

SHORT TERM...66-Tomaselli
LONG TERM....55-MM
AVIATION...66-Tomaselli