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778
FXUS64 KBRO 161115 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
615 AM CDT Sun Jun 16 2024

...New AVIATION...

.SHORT TERM...
(Today through Monday)
Issued at 251 AM CDT Sun Jun 16 2024

The end of the weekend and the beginning of the new work week
will (hopefully) be the start of the much-discussed and
anticipated significant precipitation for Deep South Texas and the
Rio Grande Valley. The latest Tropical Weather Outlook from the
National Hurricane Center lists a 60% chance of tropical formation
over the southwestern Gulf of Mexico through the next seven days.
In the meantime, lower pressure both at the surface and in the
middle layers of the atmosphere, combined with an influx of deeper
tropical moisture (precipitable water values nearing two inches
along the immediate coast), will lead to an increase in showers
and thunderstorms during the period from east to west, a trend
depicted in the Day 1 and Day 2 Convective Outlooks from the Storm
Prediction Center. It is possible that precipitation chances
progged for Monday in the forthcoming official forecast may be a
bit too high, but will leave this in place for the successive
shift to determine, especially given the uncertain nature of the
previously- mentioned potential tropical blob south of the BRO
CWFA.

Temperature-wise, above normal values are forecast. Heat indices do
not suggest a HEAT ADVISORY during the short term forecast period,
so will cover the indices with a SPECIAL WEATHER STATEMENT today
and tomorrow.

Finally, slightly more adverse marine conditions, courtesy of a
slight increase in seas, will lead to a MODERATE RISK of rip
currents at the local beaches on Monday.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 251 AM CDT Sun Jun 16 2024

The biggest story of the long term forecast period remains the
potential development of a tropical cyclone in the Bay of Campeche.
However there are still some uncertainties in regards to the
development of this tropical cyclone. One is that the models have
continued to further push the development of this system into a
tropical depression further and further back in time. While NHC has
also continued to keep the chance of development around 60 percent,
there discussions have also hinted a few uncertainties due to the
models also delaying the development of this system. Expecting
development around the middle of the week. The environmental
conditions are still favorable for the development of a tropical
cyclone, but it just appears to be slow development at this time.

The synoptic pattern for the long term features a mid-level ridge
over the Western Gulf of Mexico and the parts of Texas. However
there is a weakness that is expected to open up to allow for the
transport of moisture northward, which will lead to an increase of
rain chances for Deep South Texas and the Rio Grande Valley despite
the development of a tropical system. Based on the latest model
guidance the greatest chances of rainfall are expected to occur
between Wednesday to late Thursday with PoPs currently around 70
percent. WPC has all of Deep South Texas and the Rio Grande Valley
in a slight risk (Level 2 of 4) for Wednesday. However, the rainfall
could start much sooner, with some models brining the rain around
late Monday along the coastal regions, then spreading to inland
areas during the day on Tuesday. While the bulk of the much needed
rainfall is currently expected to occur on Wednesday and Thursday,
there is the possibility of scattered showers and thunderstorms
occurring on Friday and Saturday, though the rain chances do start to
diminish further into the weekend.

As for the temperatures, there is a high degree in uncertainty due
to the interactions with the cloud coverage. However given that the
current expectations are for plenty of cloud coverage associated
with the rain should keep the highs down a bit. As such, high
temperatures are expected to be in the range of upper 80s and low
90s for most of the long term forecast period. The exception to this
being Monday as high temperatures are in the range of mid 90s for
Deep South Texas and the Rio Grande Valley. The low temperatures are
expected to be mostly in the 70s, though a few places could get into
the low 80s.

For those looking to go to the beach during the week, need to pay
attention each day due to the unsettled weather during the mid to
late week. Beach hazards are expected to be present including an
increase rip current threat, high surf, and coastal flooding.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 610 AM CDT Sun Jun 16 2024

Light to moderate winds and partly cloudy skies will prevail at
the aerodromes through the next 24 hours. Full VFR is anticipated
with little to no chance of precipitation.
-- End Changed Discussion --

&&

.MARINE...
Issued at 251 AM CDT Sun Jun 16 2024

Today through Monday...Generally light to moderate winds and low
to moderate seas will occur along the Lower Texas Coast during the
period, with high pressure the dominant feature over the western
Gulf of Mexico. Although Small Craft Advisory is not likely, Small
Craft Should Exercise Caution may be needed for the Gulf of
Mexico waters from 20 to 60 nautical miles offshore on Monday as
the pressure gradient begins to intensify just slightly.

Monday night through Saturday...While the initial conditions will be
favorable, marine conditions are expected to become adverse and then
hazardous for the majority of the period through Saturday. While the
extent of the hazardous conditions will be dependent upon the
development of the tropical cyclone in the Bay of Campeche. An
enhanced pressure gradient will also be a driving force for the
marine hazards through Saturday as well. Winds and seas are expected
to reach Small Craft Exercise Caution conditions on Tuesday and then
move into Small Craft Advisory on Wednesday or Thursday for the
Laguna Madre. However, the onset of Small Craft Advisory for the
Gulf waters will be sooner as the seas are expected to build much
sooner and could get up to around 9 to 11 feet. Showers and
thunderstorms are expected to be present starting Monday and last
through much of Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             96  80  95  80 /  10  40  70  50
HARLINGEN               98  76  95  77 /  10  30  60  40
MCALLEN                 99  79  98  79 /  10  10  40  20
RIO GRANDE CITY        100  78  99  78 /   0   0  20  10
SOUTH PADRE ISLAND      89  82  88  82 /  20  50  70  60
BAYVIEW/PORT ISABEL     93  79  92  79 /  10  40  70  50

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
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None.
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&&

$$