-- Discussion containing changed information from previous version are highlighted. --
631
FXUS64 KBRO 220835
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
335 AM CDT Sat Jun 22 2024

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

.SHORT TERM...
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(Today through Sunday)
Issued at 331 AM CDT Sat Jun 22 2024

Key Messages:

- There is a 50% chance of tropical cyclone development near the Bay
of Campeche over the next 48 hours and beyond.

- Minor coastal flooding will be possible due to elevated seas and
tides, and a high risk of rip currents will continue today.

Deep South Texas will remain in an unsettled weather pattern through
the short term period as an area of low pressure translates west
over the Bay of Campeche toward Southeast Mexico. Pulses of moisture
will move north as mostly moderate, intermittent showers and
thunderstorms, supporting higher rain chances for the RGV and deep
South Texas. Rain amounts for today and Sunday could reach an inch
or more for some areas.

Meanwhile, a mid/upper level ridge centered over the Southeast
United States will shift west to over Texas. High pressure, too,
will build over East Texas and the Northwest Gulf. It remains to be
seen whether the ridging and high pressure, or the Southwest Gulf
low pressure will gain the upper hand transitioning beyond the short
term. However, right now there is a humidity gradient between
subsident air to the north and more moist, tropical air over
portions of deep South Texas. This humidity line is forecast to
shift north as tropical moisture deepens locally.

Satellite imagery and surface observations indicate a broad area of
low pressure over the Bay of Campeche. Environmental conditions
appear conducive for gradual development of this system as it moves
slowly west-northwestward or northwestward, and a tropical
depression could form over the southwestern Gulf of Mexico this
weekend.

Otherwise, the combination of increased cloud cover and rain chances
will result in near to slightly below normal temperatures for mid
June, with high temps ranging from the upper 80s to lower 90s. Low
temperatures region wide will be mostly in the middle 70s. Look for
mostly cloudy skies and light to moderate northeast to east winds.

Hazards: There is a high rip current risk for today and tonight,
possibly lowering to a moderate risk on Sunday. While beach and
coast conditions are not ideal, they are slowly improving.
Nonetheless, some beach runup may occur through high tide around
8:09 AM today.
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&&

.LONG TERM...
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(Sunday night through Friday)
Issued at 331 AM CDT Sat Jun 22 2024

Lingering tropical moisture could support some showers and
thunderstorms into the day Monday. Additional impacts are possible
depending on how the tropical disturbance evolves this weekend.

 Through the remainder of the week, upper level ridging and
sustained southeasterly surface flow will likely support warmer
temperatures and lower rain chances. Some isolated sea breeze
convection could occur during the afternoons from Tuesday to
Friday. The best chances for rain with the seabreeze activity
would likely be along and east of I-69C. Increasing temperatures
and dewpoints through the week will lead to higher heat index
values, potentially requiring heat advisories for the later half
of the week.
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&&

.AVIATION...
(06Z TAFS)
Issued at 1209 AM CDT Sat Jun 22 2024

Currently, KMFE is experiencing clear skies while KBRO and KHRL
have scattered VFR conditions due to clouds arriving onshore in a
westward track. These clouds are in association with a broad low
pressure system in the Bay of Campeche, which is slowly advancing
west-northwest, which will increase clouds and moisture across
all TAF sites overnight and through tomorrow. As a result, rounds
of showers and thunderstorms are expected across all aerodromes
with broken VFR ceilings lowering to overcast MVFR ceilings by
tomorrow afternoon. Models are hinting at a more solid chance for
showers and thunderstorms around sunrise and following sunset
tomorrow.

&&

.MARINE...
Issued at 331 AM CDT Sat Jun 22 2024

Today through Sunday...Moderate east winds and elevated seas will
prevail through the period and result in Small Craft Exercise
Caution to low end Small Craft Advisory conditions. An unstable
tropical air mass to the south will support scattered to numerous
showers and isolated thunderstorms. The NHC currently has a 50%
chance of tropical development near the Bay of Campeche over the
next 48 hours, which could ultimately result in higher winds and
seas than currently forecast.

Sunday night through Friday...Conditions at the start of the long
term period will likely depend on what happens with the tropical
disturbance in the Bay of Campeche this weekend. Some adverse
conditions necessitating Small Craft Should Exercise Caution
headlines may be possible on Monday. The remainder of the period
looks more favorable, with light to moderate southeasterly winds
and slight to moderate seas returning for the remainder of the
period.

&&

.MARINE...
Issued at 216 PM CDT Fri Jun 21 2024

Tonight through Saturday night...Moderate northeast to east winds
and elevated seas will prevail through the period and result in
Small Craft Exercise Caution to Small Craft Advisory conditions over
the Gulf of Mexico and Laguna Madre. Scattered to numerous showers
and isolated thunderstorms will remain likely through the period the
airmass remains unsettled. The NHC currently has a 50% chance of
tropical development near the Bay of Campeche over the next 48
hours, which could result in higher winds and seas than currently
forecast.

Sunday through Friday...Latest models continue to show a weaker
and less broad tropical low pressure area moving over the
Southern Gulf waters. This translates into a smaller wind field
with lower winds and lower seas. Conditions on Sunday look to in
the exercise caution to low end small craft advisory level as the
tropical entity approaches the Mexican coast about 300 miles
south of the mouth of the Rio Grande. As high pressure builds over
the northern Gulf the remainder of the week winds and seas will
be trending lower with light to moderate winds and slight seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
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BROWNSVILLE             87  79  90  79 /  90  90  90  50
HARLINGEN               88  75  90  76 /  90  70  80  30
MCALLEN                 88  77  90  78 /  90  70  90  30
RIO GRANDE CITY         87  76  87  76 /  90  70  80  30
SOUTH PADRE ISLAND      86  82  87  82 /  90  80  80  40
BAYVIEW/PORT ISABEL     87  78  89  78 /  90  80  80  40
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&&

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

     High Surf Advisory until 7 AM CDT this morning for TXZ451-454-
     455.

GM...None.
&&

$$

SHORT TERM...54-BHM
LONG TERM....60-BE
AVIATION...65