272
FXUS64 KBRO 221731
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1231 PM CDT Sat Jun 22 2024

...New AVIATION...

.SHORT TERM...
(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.

&&

.LONG TERM...
(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.

&&

.AVIATION...
(18Z TAFS)
Issued at 1231 PM CDT Sat Jun 22 2024

The latest radar and satellite imagery reveal widely scattered
SHRA and BKN to OVC cloud cover across the region this afternoon.
Cloud cover and precipitation is associated with a broad area of
low pressure near the Bay of Campeche, which will continue to
slowly track westward into Mexico through tomorrow. This will
result in periods of light to moderate SHRA and isolated -TSRA
through the TAF period. The main threats will be locally heavy
rain and gusty winds...and lightning with any thunderstorms.
Expect ceilings to fluctuate between VFR and MVFR, and reduced
visibility with more robust showers. Otherwise, winds will remain
out of the east to southeast around 5 to 10 knots with occasional
gusts to around 15-20 knots.

&&

.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.

&&

.PRELIMINARY POINT TEMPS/POPS...
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

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Coastal Flood Advisory until 7 PM CDT this evening for TXZ351-
     354-355-451-454-455.

     High Rip Current Risk through Sunday morning for TXZ451-454-455.

GM...None.
&&

$$

SHORT TERM...54
LONG TERM....60
AVIATION...22-Garcia