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000
FXUS64 KBRO 210913
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
413 AM CDT Sun Apr 21 2024

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

.SHORT TERM...
(Today through Monday)
Issued at 411 AM CDT Sun Apr 21 2024

A cold front is currently moving south across Deep South Texas and
is expected to be south of the Rio Grande River around sunrise.
Brownsville radar indicates a large cluster of showers and
thunderstorms well south of the Rio Grande Valley, moving farther
south across Northeast Mexico. Scattered showers and isolated
thunderstorms will linger through the morning and early afternoon
hours across the Rio Grande Valley as warm, humid air rises above
the frontal boundary. Today will be much cooler as breezy north
winds, cloudy skies and lingering rain prevail across the region.

High temperatures will reach the upper 60s across the Northern
Ranchlands and low 70s across the Rio Grande Valley, mainly this
morning. Temperatures are expected to steadily fall through the
afternoon into the 60s with the arrival of the cooler airmass.
Leaned towards a NBM/ConsShort/ConsAll blend or mix for temperatures
for today and tonight, as the NBM temperatures seemed a bit too
warm. Wind gusts around 20-30 MPH will be likely beginning by mid to
late morning. Winds will begin to diminish this evening as
high pressure settles into the region.

Lows tonight will fall into the mid 50s across the Rio Grande Plains
and the Northern Ranchlands and into the low to mid 60s across the
Rio Grande Valley and along the coast. Lingering low rain chances
will possible tonight and Monday.

A High Risk of Rip Currents will be likely along the Lower
Texas Coast today into tonight due to increasing seas. A Moderate
Risk of Rip Currents is expected on Monday.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 411 AM CDT Sun Apr 21 2024

Key Messages:

* Warmth and humidity increases through the week and into next
  weekend

* Becoming breezy Thursday through next Sunday

* Adverse marine conditions developing Thursday PM through Sunday

Dry and tranquil weather conditions will prevail through the long-
term forecast period with a ~1016 mb surface high pressure system in
place. Global deterministic forecast models and ensemble are
advertising a amplified ridge axis approaching from the west Tuesday
before being overhead on Wednesday. Thursday through next weekend,
an anomalously strong trough is expected to dive into the
Southwestern U.S. This in turn will result in downstream ridging
over the eastern half of the country with a southwest flow aloft
pattern over Deep South Texas. Near the sfc, the local forecast area
will be on the western flank of a high pressure system to the east.

A strengthening pressure gradient with low pressure systems over the
mountains of north-central Mexico will drive a strengthening low
level jet (LLJ) over the area. Ultimately, this will result in
breezy south-southeast winds over Deep South Texas and the Lower Rio
Grande Valley which will aid in stronger moist and warm air
advection (WAA) over the area Thursday through Sunday.

That said, we`ll see temperature and humidity levels rebound this
week into next weekend. Wednesday will start off with daytime highs
ranging between the upper 80s to lower 90s. By Saturday/Sunday of
next weekend, daytime highs will range between the lower 90s to
lower 100s with dewpoints in the lower 70s. Overnight lows are
expected to be in the lower to mid 70s for much of the long-term
period.

&&

.AVIATION...
(06Z TAFS)
Issued at 1245 AM CDT Sun Apr 21 2024

Light to moderate east to southeast winds with some low cloud
decks prevail across Deep South Texas early this morning. A mix of
VFR to MVFR ceilings are expected to continue across the area
tonight as a cold front approaches from the north. Thunderstorms
are possible, mainly west of MFE into mid morning. This may bring
a period of LIFR conditions. Breezy northeasterly winds follow
into this afternoon with persistent cloud cover through the TAF
period.

&&

.MARINE...
Issued at 411 AM CDT Sun Apr 21 2024

Now through Monday...A cold front is currently moving through the
Lower Texas Coast waters. The front should be south of the Rio
Grande River around sunrise. In the wake of the front, increasing
winds and building seas will result in Small Craft Advisory
conditions along the Laguna Madre through later this evening and on
the Gulf waters late tonight. Small Craft Advisories may be needed
for offshore Gulf of Mexico waters on Monday. Additional scattered
showers and isolated thunderstorms will be possible through the
period.

Monday Night through Saturday Night....The long-term period will
start off Monday night into Tuesday with favorable marine
conditions with light to moderate winds and seas. By the time we
get into Thursday PM into next weekend, more adverse marine
conditions are expected to develop amid the tightening of the
pressure gradient and strengthening of boundary layer winds. Small
Craft Exercise Caution conditions will be possible Thursday PM
through Friday PM before Small Craft Advisory conditions become
possible over next weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             77  65  74  66 /  50  30  20  10
HARLINGEN               75  62  74  62 /  30  20  20   0
MCALLEN                 75  63  74  63 /  40  30  20   0
RIO GRANDE CITY         70  59  72  61 /  60  30  20   0
SOUTH PADRE ISLAND      75  68  72  69 /  50  30  20  10
BAYVIEW/PORT ISABEL     76  65  74  66 /  40  20  20  10

&&

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

GM...Small Craft Advisory until 10 PM CDT this evening for GMZ130-132-
     135.

     Small Craft Advisory until 7 AM CDT Monday for GMZ150-155-170-
     175.

&&

$$

SHORT TERM...63-KC
LONG TERM....23-Evbuoma
AVIATION...63-KC