289
FXUS64 KBRO 181753 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1253 PM CDT Tue Jun 18 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 416 AM CDT Tue Jun 18 2024

The primary concern for the short term period will be a tropical
disturbance that is developing over the Southern Gulf. The latest
NHC forecast has this system moving north then westward,
strengthening slightly before making landfall in Mexico. This will
likely advect deep tropical moisture to the region, bringing the
opportunity for showers and thunderstorms starting as early as
this morning and continuing through the period. The greatest
opportunity for showers and thunderstorms looks to be Tuesday
night through the end of the period. A large wind field extending
to the north of the system could support tropical storm force
winds along the Island and Coastal portions of Kenedy, Willacy,
and Cameron Counties. A Tropical Storm Warning is in place for
Island and Coastal portions of Kenedy, Willacy, and Cameron
Counties.

Heavier rains tonight and Wednesday could pose a threat for flash
flooding, though the bulk of the rain is expected to pass to the
north. The WPC has a slight risk for excessive rainfall over the
coastal counties today, and across the CWA on Wednesday. The wind
threat associated with this system is expected to decrease as the
system moves further inland.

Stronger winds and elevated seas are expected to produce hazardous
conditions along the area beaches. High Surf, Rip Currents, and
some Moderate Coastal Flooding are anticipated with this system.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 416 AM CDT Tue Jun 18 2024

The tropical system will continue to impact the region through
the start of the long term period, with rain chances potentially
lingering into the weekend. An upper level high pressure system
centered over Texas and the Southern Plains will continue to
support easterly to southeasterly winds over Deep South Texas,
potentially funneling additional tropical moisture into the region
through the period.

Beach conditions will likely improve over the weekend as seas
begin to diminish in the wake of this system.

&&

.AVIATION...
(18Z TAFS)
Issued at 1251 PM CDT Tue Jun 18 2024

Through 18z Wednesday....

Aviation IDSS Key Messages:

* Isolated showers to become more numerous this afternoon; some
  embedded thunder is possible

* Rain/thunder threat increases tonight and continues through
  Wednesday

* IFR, possibly LIFR cigs/vsbys are possible under any
  thunderstorms that do develop

VFR conditions are taking place at all of the terminals under a FEW-
BKN deck of cumulus and stratocumulus clouds per the latest GOES-16
satellite imagery, with cloud bases between 3,000-6,000 feet AGL and
unrestricted visibilities.

The main concern during the 18z TAF cycle will be the increased
chances for showers and thunderstorms. According to the latest
radar, satellite and model observations, isolated showers and maybe
some embedded thunder are expected to become more scattered about
the area this afternoon as sfc daytime heating and influx of deep
tropical moisture from a developing tropical system to our south
increases. The main uncertainty is whether these showers make it
to any of the terminals this afternoon as they are very much hit
or miss given the isolated to scattered nature. Given the
situation, have VCSH in the TAFs for this afternoon into this
evening.

Through tonight and into Wednesday morning, showers and
thunderstorms are expected to become more numerous across the area
as the core of the tropical entity moves closer to land. However,
the main uncertainty is where exactly the rain bands set up. That
said, have Prob30 groups in the TAFs for now. Any showers or storms
that move over a terminal will have the capabilities of reducing
cigs/vis down to IFR and maybe even LIFR under the most intense
rainfall. Otherwise, expect for VFR conditions to prevail.

Winds will continue out of the east 15-25 kts with gusts as high as
35 kts or so through the TAF period. Winds will become strongest
towards the latter parts of the 18z TAF period in response to the
tropical system.

&&

.MARINE...
Issued at 416 AM CDT Tue Jun 18 2024

A tropical disturbance in the Southern Gulf of Mexico is expected
to move slowly northward then westward, making landfall in Mexico.
A large wind field extending to the north of this system will
likely support high seas as well as the potential for Tropical
Storm Force winds. Winds and seas are expected to improve over the
weekend, with light to moderate winds and moderate seas continuing
through the remainder of the period. A Tropical Storm Warning is
in place for the Laguna Madre and Coastal Gulf waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             79  89  81  90 /  90 100 100 100
HARLINGEN               76  87  78  91 /  80 100 100 100
MCALLEN                 78  86  80  89 /  60 100 100  90
RIO GRANDE CITY         77  84  77  87 /  50 100 100  90
SOUTH PADRE ISLAND      80  86  83  87 /  90 100 100  90
BAYVIEW/PORT ISABEL     77  88  80  89 /  90 100 100 100

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Tropical Storm Warning for TXZ351-354-355-451-454-455.

     Flood Watch from late tonight through Thursday afternoon for
     TXZ248>255-351-353>355-451-454-455.

     Coastal Flood Warning from 1 AM Wednesday to 1 PM CDT Thursday
     for TXZ351-354-355-451-454-455.

     High Rip Current Risk through Wednesday evening for TXZ451-454-
     455.

     High Surf Advisory until 7 PM CDT Wednesday for TXZ451-454-455.

GM...Tropical Storm Warning for GMZ130-132-135-150-155-170-175.

&&

$$

SHORT TERM...60-BE
LONG TERM....60-BE
AVIATION...23-Evbuoma