627
FXUS64 KBRO 300854
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
354 AM CDT Thu May 30 2024

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

.SHORT TERM...
(Today through Friday)
Issued at 349 AM CDT Thu May 30 2024

Deep South Texas remains along the northeastern periphery of the
mid to upper level ridge centered over Mexico. At the surface,
broad high pressure across the Gulf of Mexico will support a
steady return of higher humidity. The combination of increasing
low level moisture and subsidence aloft will lead to above normal
temperatures and high heat indices.

Highs today will range from the mid to upper 90s for most of the
region, with a few locations reaching 100 degrees across the Rio
Grande Plains. Heat indices will range between 105 to 110 degrees,
with a few areas reaching 111 degrees in the afternoon. Therefore,
have decided not to issue a Heat Advisory for today, since the heat
indices are expected to remain just below criteria. Lows tonight
will fall into the upper 70s to lower 80s. Highs on Friday, a couple
of degrees warmer than today, will range from the 80s at the
beaches, mid to upper 90s across the eastern half of the CWA and the
triple digits across portions of the Rio Grande Plains. A Heat
Advisory may be needed on Friday, as heat indices may reach or
exceed 111 degrees across some parts of the area.

Another embedded disturbance within northwesterly flow aloft could
result in thunderstorms developing to our north and west late Friday
afternoon. SPC has all of Deep South Texas in a general thunderstorm
risk for Friday (Day 2). However, rain chances remain very low
(below 15 percent) through Friday afternoon.

A Moderate rip current risk continues along area beaches today
through Friday.

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 349 AM CDT Thu May 30 2024

An upper-level ridge located over Northern Mexico and the
Southwestern US looks to be the dominant feature through the long
term period. A shortwave disturbance moving through the upper-
level flow Friday night into Saturday could provide some weak
forcing over Deep South Texas, and the possibility for isolated
showers and thunderstorms. However, most model guidance is keeping
this feature further north, with Deep South Texas remaining rain
free through the period. The ECMWF is the primary exception, and
continues to show more robust rain chances across the area.
Additionally, dry mid levels and a relatively well capped
environment will likely favor drier conditions, though enough CAPE
is present to support some isolated thunderstorms. Given the
uncertainty and slightly more favorable conditions Friday night,
PoPs have been left around 20%. Lower confidence and less
favorable conditions support rain chances around 10% on Saturday.
Beyond that, rain chances look to remain near zero through the
remainder of the period.

The primary concern for the long term period will continue to be
heat. The upper level ridge is expected to strengthen through the
period, providing broad subsidence aloft and supporting mostly
sunny skies each afternoon. At the surface, moderate southeasterly
flow will continue to provide a supply of warmer air and
additional moisture, supporting the development of low clouds
overnight. This combination will allow for greater warming each
afternoon, while limiting cooling at night.

High temperatures are expected to slowly climb through the period,
with much of the area in the upper 90s on Saturday climbing into
the low 100s early next week. Heat indices look to briefly peak
around 110-112 each afternoon this weekend, though the duration
looks to be short enough to avoid Heat Advisories. By Tuesday,
however, Heat Advisories will again be likely, as heat indices
approach 115.

&&

.AVIATION...
(06Z TAFS)
Issued at 1237 AM CDT Thu May 30 2024

Mostly clear skies and light east-southeast winds prevail across
Deep South Texas early this morning. Latest satellite imagery and
surface observations indicate some low MVFR cloud decks west and
south of the aerodromes. Low clouds/ceilings are expected to
increase over the region through the overnight hours. Will mention
a TEMPO at BRO and MFE between 07-10Z for brief MVFR ceilings.
MVFR conditions, including some patchy fog, will be possible
around daybreak. Otherwise, VFR conditions are expected to return
mid to late morning as southeast winds increase, some wind gusts
around 25 knots will be possible this afternoon.

&&

.MARINE...
Issued at 349 AM CDT Thu May 30 2024

Today through Friday...Moderate to fresh southeast winds and
moderate to slightly enhanced wave heights will prevail along the
Lower Texas Coast with high pressure across the Gulf. Operators of
small craft should exercise caution on the Laguna Madre and the
nearshore Gulf waters today as winds increase. Small craft exercise
conditions will continue on the Laguna Madre and nearshore Waters
and develop on the offshore Gulf waters tonight. A Small Craft
Advisory may be needed late tonight or Friday for the offshore Gulf
waters as seas build.

Friday night through Wednesday...Surface high pressure over the
Northern Gulf looks to remain in place through the long term
period, supporting moderate southeasterly winds and moderate seas.
Small Craft Should Exercise Caution headlines will likely be
needed through most of the period. The occasional Small Craft
Advisory could be needed as well, with winds forecast to approach
20 knots each afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             95  81  94  83 /  10  10  10  10
HARLINGEN               97  79  97  79 /  10  10  10  10
MCALLEN                 98  80  98  81 /  10  10  10  20
RIO GRANDE CITY        100  79 101  80 /   0  10  10  20
SOUTH PADRE ISLAND      85  81  87  82 /  10  10  10  20
BAYVIEW/PORT ISABEL     92  81  93  81 /  10  10  10  10

&&

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

$$

SHORT TERM...63-KC
LONG TERM....60-BE
AVIATION...63