619
FXUS64 KBRO 240533 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1233 AM CDT Tue Jun 24 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 915 PM CDT Mon Jun 23 2025

The short term forecast period will feature near normal
temperatures with minor heat risk and day-to-day shower and
thunderstorm chances as the region sits on the southwestern
periphery of an anomalously strong and broad, yet weakening 597
hpa sub-tropical ridge or "heat dome" over the eastern U.S.

Through this evening, isolated rain showers will continue to wane in
coverage and probability, and cloud coverage will continue to show
improvements with the loss of daytime heating. This will give way to
another warm and humid night.

The shear size of the aforementioned "heat dome" over the eastern
U.S. has created a "Ring of Fire" pattern or areas of convection
along the periphery of this feature. While most of the monsoonal
flow and associated shower and thunderstorm activity will be placed
to our west-northwest (i.e. Northern Mexico and New Mexico), Tuesday
and Wednesday will both pose low to medium (20-40%) chances for
isolated to scattered diurnally driven showers and thunderstorms
across Deep South Texas and the Rio Grande Valley.

While the upper air/jet dynamics don`t support any organized or
severe convection, any showers or thunderstorms that develop will
continue to pose a heavy rainfall threat due to the continued
elevated atmospheric moisture content available. Some storms could
become strong producing gusty winds as well.

Otherwise, expect for continued very warm to hot and humid
conditions on Tuesday and Wednesday with daytime high temperatures
expected to top out in the low to mid 90s, except along South
Padre Island and the Lower Texas Coast, where highs are expected
to be in the 80s. Tuesday night will be similar to tonight. That
being warm and humid with overnight lows in the 70s.

A moderate risk for rip currents will exist through Tuesday.

&&

.LONG TERM...
(Thursday through next Tuesday)
Issued at 915 PM CDT Mon Jun 23 2025

The long term forecast period will continue to see near normal
temperatures through the balance of the forecast period, though
there may be slight increases in temperatures and heat risk Saturday
into the early parts of next week as the aforementioned "heat dome"
over the eastern U.S. breaks down (weaken) and begins to
shift/retrograde westward.

While the large-scale 500 mb pattern will begin to undergo a change
during the extended, there will continue to be near day-to-day
chances (15-30%) for showers and thunderstorms across parts of Deep
South Texas, with the best chance being areas near the Lower Texas
Coast, the Lower Rio Grande Valley and the Gulf Waters. This is
particularly the case Wednesday night through Saturday.

Better chances and coverage for diurnally driven showers and
thunderstorms, potentially along a seabreeze, will arrive on Sunday
and Monday. Chances/probabilities increases to low to medium (20-
40%) on Sunday and Monday with the greatest chance and coverage of
rain once again being favored for areas near the coast (i.e. along
and east of IH-69C) and over the Gulf Waters. Given the elevated
precipitable water (PWAT) values, any showers or thunderstorms will
be capable of producing heavy rainfall. Additionally, some of these
storms could become strong capable of producing gusty winds.

&&

.AVIATION...
(06Z TAFS)
Issued at 1221 AM CDT Tue Jun 24 2025

VFR conditions are expected to persist through the TAF cycle at
all TAF sites. Southeasterly winds are expected to remain as
well with winds gusting up to 25 knots possible during the
afternoon hours. There is a low chance of showers and
thunderstorms during the afternoon as well, however confidence is
too low to include in the TAF package.

&&

.MARINE...
Issued at 915 PM CDT Mon Jun 23 2025

Generally favorable marine conditions will prevail with low to
moderate seas and light to moderate winds. A locally enhanced
pressure gradient may result in brief Small Craft Exercise Caution
conditions along the Laguna Madre and nearshore Gulf waters each
afternoon. Otherwise, day-to-day or near day-to-day isolated to
scattered showers and thunderstorms will continue through the week
over the Gulf waters and Laguna Madre.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             92  76  92  77 /  20   0  30  20
HARLINGEN               92  73  92  74 /  20   0  30  10
MCALLEN                 95  75  95  76 /  20   0  20   0
RIO GRANDE CITY         93  74  93  74 /  10   0  10   0
SOUTH PADRE ISLAND      87  79  87  79 /  20  10  30  20
BAYVIEW/PORT ISABEL     90  76  90  76 /  20  10  30  10

&&

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

$$

SHORT TERM...23
LONG TERM....23
AVIATION...64-Katz