957
FXUS64 KBRO 191140 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
540 AM CST Sun Jan 19 2025

...New AVIATION...

.SHORT TERM...
(Today through Monday)
Issued at 443 AM CST Sun Jan 19 2025

Arctic high pressure pressure will continue to build into Texas
today and bring a prolonged period of very cold temperatures to
the Rio Grande Valley. Strong cold air advection (CAA) will result
in temperatures falling through the day. Daytime high temps today
are expected to fall and remain steady in the 40s, but a few
locations may remain in the 50s, especially along the coast. Lows
tonight will fall into 30s across much of the area. Tuesday will
remain chilly with highs in generally in the 40s. However, a
coastal trough is forecast to develop Monday afternoon, and
temperatures along the coast may recover and reach the low to mid
50s in the afternoon. A surge of moisture combined with the
develop of a coastal trough will support increasing clouds and
rain chances on Monday.

A Freeze Warning has been issued for portions of the northern
ranchlands and includes Zapata, Jim Hogg and Brooks Counties from
Midnight tonight until 9 AM Monday. The brisk north winds will
also produce very cold "feel like temperatures" temperatures
across portions of the northern ranchlands and the Brush Country
late tonight into Monday morning. Therefore, a Cold Weather
Advisory has been issued for Zapata, Jim Hogg, Brooks and Kenedy
Counties from midnight tonight until 9 AM Monday morning.

Breezy north winds combined with much drier air (RH values in the
20`s) may lead to elevated fire conditions across portions of
Deep South Texas today, especially along and east the of the
I-69C/US Hwy 281 corridor later this morning into the afternoon.
Have issued an Rangeland Fire Danger Statement /RFD/ for today.

There is a High Risk of rip currents along area beaches through the
period.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 443 AM CST Sun Jan 19 2025

- Freezing temps will be possible Monday night/Tuesday morning for
  much of the CWA. Freezing rain/drizzle/wintry precip will also
  be possible for the brush country (Zapata, Jim Hogg, and Brooks
  Counties).

- Near record to record setting cold weather Tuesday night to
  Wednesday morning.

Cold weather and the associated impacts will be front and center
for the long term. A coastal trough will lie right over the coast
Monday night while a surge of high pressure back doors south into
western sections of the the CWA. Monday night will see some
freezing temperatures across the northern tier and even south
central sections and even possible freezing/rain/drizzle/wintry
precip for the brush country. Have issued a winter storm watch for
freezing drizzle for the brush country. The remainder of the CWA
will likely see rain/drizzle as Gulf moisture funnels in via the
coastal trough. High pressure will tend to diminish the trough on
Tuesday as it spreads offshore. Tuesday temps will be in the 30s
and 40s. Rain chances will diminish Tuesday into Tuesday night.

Unfortunately for us Tuesday night, it will be drier with some
overnight clearing, and unusually cold weather for this time of
year, even historically cold, will result in temperatures in the
20s for the entire CWA along with wind chill readings in the
lower 20s and teens. The low temperature record most likely to be
broken Wednesday morning will be that for McAllen which is 33
degrees (1959). The current forecast calls for upper 20s in the
mid- Valley Wednesday morning. Daytime temps will trend higher
later in the week, but clearing skies will promote colder
overnight weather. Wednesday night and Thursday night will also
feature sub- freezing temps for the brush country.

As mentioned, the air mass will modify late in the week with
temperatures trending upward. Weather conditions will be dry with
high pressure spreading over the area. Believe it or not, temps
are forecast to rise into the 70s on Saturday as south winds
return to the area.

&&

.AVIATION...
(12Z TAFS)
Issued at 531 AM CST Sun Jan 19 2025

Breezy north winds with some passing mid level clouds prevail
across Deep South Texas early this morning. Winds are expected to
gradually decrease later this afternoon into this evening. VFR
conditions at all RGV aerodromes are expected through the next 24
hours.

&&

.MARINE...
Issued at 443 AM CST Sun Jan 19 2025

Today through Monday...Latest observations indicate moderate to
strong north winds and seas around 7 seas feet across the Laguna
Madre and the Gulf waters. Hazardous marine conditions are
expected to continue along the Lower Texas coast today. A Small
Craft Advisory remains in effect for the Laguna Madre until 3 PM
this afternoon and for the Gulf Waters until midnight tonight.
There is a medium chance (30 to 50 percent) of some gale force
gusts between 5 to 9 AM this morning. Due to the short duration
and low confidence that frequent gale force will occur, have opted
to keep the current Small Craft Advisory in place. However, can`t
rule out a few gale force gust through mid-morning. Marine
conditions will gradually improve later tonight into early Monday
with winds decreasing and seas briefly subsiding. Winds and seas
are expected to become elevated to adverse on Monday afternoon as
a coastal trough develops.

Monday night through Thursday night...Overland high pressure
interacting with coastal lower pressure (coastal trough) will
sustain a tight pressure gradient and strong north winds through
at least Tuesday night. We will plan on at least an ongoing small
craft advisory. There are a few gusts to gale force in the grids,
so we may need to post a gale watch for portions of the Monday
night to Tuesday night surge. Though winds will diminish after
Tuesday night, high seas on the Gulf will continue to meet small
craft advisory criteria.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             53  41  52  38 /   0   0  40  70
HARLINGEN               52  36  50  32 /   0   0  50  80
MCALLEN                 55  38  49  35 /   0   0  30  70
RIO GRANDE CITY         54  34  48  33 /   0   0  20  60
SOUTH PADRE ISLAND      53  48  58  45 /   0   0  60  80
BAYVIEW/PORT ISABEL     53  42  54  38 /   0   0  50  80

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Freeze Warning from midnight tonight to 9 AM CST Monday for
     TXZ248>250.

     Winter Storm Watch from late Monday night through Tuesday
     morning for TXZ248>250.

     High Rip Current Risk through Monday afternoon for TXZ451-454-
     455.

GM...Small Craft Advisory until 3 PM CST this afternoon for GMZ130-
     132-135.

     Gale Watch from Tuesday morning through Tuesday afternoon for
     GMZ130-132-135-150-155-170-175.

     Small Craft Advisory until midnight CST tonight for GMZ150-155-
     170-175.

&&

$$

SHORT TERM...63-KC
LONG TERM....54-BHM
AVIATION...63-KC