Gale Warning 3, NWS Brownsville, TX

Area Forecast Discussion
National Weather Service Brownsville TX
336 AM CST Mon Jan 15 2024

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

.SHORT TERM...
(Today through Tuesday)
Issued at 334 AM CST Mon Jan 15 2024

Key Messages:

...Much colder temperatures through Tuesday...
...Wind chills falling below 20 degrees...
...Possible wintry mix mid and lower rio Grande Valley...

.Short term (Today through Tuesday):Arctic cold front has cleared
all of Deep South Texas with cold air advection (CAA) well underway
and forecast through Tuesday. A shortwave trough rounding the base
of the Central Plains longwave trough sends a second surge of cold
air south late tonight with the main surface ridge settling over
Texas Tuesday. Light rain has already begun with isentropic upglide
strengthening with the 290-295k layer becoming almost instantly
saturated. Patches of light rain and drizzle continue this morning
mainly east of the I-69c/E corridor with uncertainty among the 00Z
model output when the first round of rain might end. Currently the
forecast calls for the rain chances to tapper off this afternoon
before another round redevelops with the second surge of high
pressure late tonight and Tuesday morning. This second round of
precipitation may include a wintry mix of freezing rain, patches of
sleet and possible snow flurries as forecast soundings indicate the
saturated layer dipping below 0C with the arctic air deepening to
near 3000 feet. Favored areas along and either side Interstate
highway 2 from Pharr, Weslaco to Harlingen and along I-69 E north of
Harlingen and possibly as far south as Brownsville and Bayview may
see a few snow flakes but do not expect any accumulations with the
ground rather warm. Any ice accumulations are likely to remain trace
amounts and impact elevated surfaces like overpasses and bridges.
Confidence is below average and duration of the potential wintry mix
should be short-lived so not planning on a winter weather advisory
at this time.

Otherwise, A whole slew of other winter weather products have been
issued starting with a wind chill advisory this morning for all
areas except the Lower RGV and Padre Island. Freeze warnings go into
affect late tonight into Tuesday with wind chill warnings starting
up tonight as the pressure gradient tightens with the second surge
of high pressure.

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 334 AM CST Mon Jan 15 2024

High pressure begins to pivot eastward into Wednesday, with low
pressure working back into the Southern Plains, allowing winds to
become fairly light Tuesday night into Wednesday before gradually
turning southeast. Model guidance had been trending drier into
Tuesday night, but have since leaned toward the coastal trough
pulling in additional moisture. This will be a good thing for the
lower to mid RGV, maintaining some sort of cloud cover and
limiting radiational cooling into Wednesday morning. Despite the
help, widespread freezing temperatures are expected Tuesday night
across the CWA, with a hard freeze likely across the ranchlands.
There could be a period of around 6 hours of freezing temperatures
across the mid to lower RGV just after midnight Tuesday night,
with portions of Willacy and Starr counties below freezing an hour
or two before and after the rest of the RGV. The northern
ranchlands could see 12 hours of subfreezing temperatures Tuesday
evening into mid Wednesday morning.

Expect temperatures to warm into the 50s Wednesday afternoon, 40s
Wednesday night, and into the 70s on Thursday thanks to some dry
downsloping southwesterly winds. The next cold front arrives
Thursday night, with a persistent coastal trough setting up
through the weekend, gradually building moisture with a chance of
cold rain or drizzle Saturday night through Sunday. Temperatures
drop into the 40s Thursday night, 60s on Friday, upper 30s to mid
40s Friday night and warm gradually back toward normal from there
into Sunday.

Dense marine fog along the coast may be possible by mid week as
well with SSTs dropping and warmer southerly flow returning
Wednesday into Thursday night. Southwesterly flow Thursday may
push any marine fog further offshore during the day, before
returning Thursday evening and night.

&&

.AVIATION...
(06Z TAFS)
Issued at 1030 PM CST Sun Jan 14 2024

A cold front currently across the Rio Grande Valley will continue
to push southward overnight. Light east to northeast winds will
turn to the north and increase through the night. Widespread MVFR
ceilings at local aerodromes will deteriorate overnight into the
early morning as cold air works into the area. IFR to LIFR
conditions will be likely, especially BRO and HRL. Besides lower
ceilings/fog/mist, a chance of light rain could complicate ground
operations.

&&

.MARINE...
Issued at 334 AM CST Mon Jan 15 2024

Today through Tuesday...The cold front is moving trough the
coastal waters this morning and should clear all areas before
Noon. Small Craft advisories have been issued for all areas for
today and this evening. Gale conditions are expected to develop
later tonight into Tuesday morning as a second surge of high
pressure builds into Texas. Cold temperatures through Tuesday with
patches of rain and some fog at times.

Tuesday Night through Sunday...High pressure works east as low
pressure develops across the Southern Plains into Wednesday,
allowing northerly winds to diminish and turn southeasterly.
Light to moderate southerly then southwesterly flow follows on
Thursday before a cold front Thursday night with increasing
northerly winds Friday. A coastal trough of low pressure
strengthens through the weekend, turning winds more easterly
Saturday and southeasterly Sunday with increasing swell and
building seas. Expect SCEC to SCA conditions behind the front
Friday afternoon through Friday night, with SCEC offshore
Saturday, and SCEC to SCA Saturday night through Sunday. Cooler
SSTs but much warmer southerly flow could set up dense marine fog
Wednesday night into Thursday night, pushing further offshore
during the day Thursday with a period of southwesterly flow. The
chance of rain returns and increases late Saturday through Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             51  33  39  32 /  30  40  30   0
HARLINGEN               44  30  40  28 /  20  40  20   0
MCALLEN                 43  30  42  30 /  10  10  10   0
RIO GRANDE CITY         44  30  42  28 /  10   0  10   0
SOUTH PADRE ISLAND      56  41  43  41 /  30  60  50   0
BAYVIEW/PORT ISABEL     51  35  40  33 /  30  50  30   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Wind Chill Advisory until 1 PM CST this afternoon for TXZ248>251.

     Wind Chill Warning from 9 PM this evening to 6 PM CST Tuesday
     for TXZ248>251-351-451.

     Freeze Warning from 2 AM to 10 AM CST Tuesday for TXZ248>251-351.

     Hard Freeze Watch from Tuesday evening through Wednesday morning
     for TXZ248>251-351.

     Wind Chill Advisory until 1 PM CST this afternoon for TXZ252-253-
     353.

     Wind Chill Warning from midnight tonight to 6 PM CST Tuesday for
     TXZ252>255-353>355-454-455.

     Freeze Warning from 5 AM to 10 AM CST Tuesday for TXZ252>255-353.

     Freeze Watch from Tuesday evening through Wednesday morning for
     TXZ252>255-353>355.

GM...Small Craft Advisory until 3 AM CST Tuesday for GMZ130-132-135-
     150-155-170-175.

     Gale Warning from 3 AM to noon CST Tuesday for GMZ130-132-135-
     150-155-170-175.

&&

SHORT TERM...59-GB
LONG TERM....56-Hallman
AVIATION...59-GB