-- Discussion containing changed information from previous version are highlighted. --
581
FXUS64 KBRO 111119 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
619 AM CDT Tue Jun 11 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 214 AM CDT Tue Jun 11 2024

Very warm, near seasonable temperatures, and humid conditions will
continue through the short term forecast period. Global weather
forecast models (GFS, ECMWF, Canadian NH) and ensembles (GEFS, ECE,
CMC) continue to advertise the strengthening/re-emergence of a 594
dam sub-tropical, Sonoran heat dome over northwestern Mexico into
the Desert Southwest. On the leeward side of this 591-594 dam heat
dome and ridge axis, Deep South Texas and the Rio Grande Valley will
be placed in a favorable location that again will yield near
seasonable temperatures today and on Wednesday, while the core of
the dangerous, searing heat grips parts of the western U.S.

850 mb temperatures ranging between 20-22C will translate the
daytime high temperatures at the surface to be upper 90s to lower
100s. Humidity values will be slightly less today than previous
days. That said, heat indices are expected to remain below criteria
for a Heat Advisory or a Special Weather Statement (SPS) with
values ranging between 104-111F.

Rain chances will be little to none today courtesy of a weakening
frontal boundary to our north-northeast, and high pressure
influences and subsidence continuing over the region as mid to upper
ridging strengthens. Another warm and muggy night tonight can be
expected with overnight lows holding in the mid 70s to near 80F.

Wednesday will feature a similar setup as today. High temperatures
are forecast to climb into the mid to upper 90s. Heat indices are
also expected to remain below a Heat Advisory or a Special Weather
Statement (SPS) with values ranging between 103-111F. Wednesday
should also be a mainly rain-free day across the local forecast
area. A weak shortwave moving towards our region coupled with a sea
breeze, could ignite a rogue shower or thunderstorm over the region
(greatest chances along and east of I-69C).

&&

.LONG TERM...
(Wednesday Night through Monday)
Issued at 214 AM CDT Tue Jun 11 2024

A slightly active weather pattern is anticipated during this
portion of the total forecast. 500 mb high pressure, initially
centered over New Mexico, will shift west to become, and remain,
centered just west of the Baja Peninsula. This will not only
produce brief mid-level troughiness along the Texas coastline,
but will also allow 500 mb low pressure, and possible surface
low pressure, to advance towards the Texas coastline from the
east. Combined with deeper tropical moisture, the result will
be  isolated to scattered showers and thunderstorms over the BRO
CWFA, mainly along and east of the Interstate 69C corridor, with
convection making it west of this demarcation on Monday.

Temperature-wise, the absence of the mid-level high, the chance
for precipitation, and increased cloud cover will result in
daytime high temperatures at slightly above normal levels for this
time of year. Although a HEAT ADVISORY is not anticipated to be
needed through a majority of the period, increased atmospheric
moisture may result in a HEAT ADVISORY on Monday for portions of
Deep South Texas and the Rio Grande Valley.

Finally, some model guidance suggests that an inverted mid-level
trough along the east coast of Mexico, combined with even deeper
tropical moisture (up to, and in excess of, 2.50 inches of
precipitable water) may produce beneficial rains across the whole
of the BRO CWFA Tuesday and Wednesday.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 618 AM CDT Tue Jun 11 2024

Through 12z Wednesday....VFR conditions were taking place at all of
the TAF sites and are expected to persist through the entirety of
the 12z TAF cycle as a sfc high pressure system maintains control
over the region.

Light and variable to calm winds will pick up out of the east-
southeast at 5-10 kts this morning and persist through the remainder
of the TAF period.
-- End Changed Discussion --

&&

.MARINE...
(Today through Wednesday)
Issued at 214 AM CDT Tue Jun 11 2024

High pressure over the north-central Gulf of Mexico and a weak
pressure gradient over the region will produce light to moderate
east to southeast winds and generally low seas through the
forecast. Convection over the Gulf will be more active this week,
with periodic isolated showers and thunderstorms along the lower
Texas coast.

(Wednesday Night through Monday)
High pressure will generally prevail over the western Gulf of
Mexico through a majority of the period. However, weak low
pressure may approach the Middle Texas Coast towards the end.
Overall, light to moderate winds and low to moderate seas are
anticipated. However, Small Craft Should Exercise Caution to
possibly even Small Craft Advisory seas may develop along the
Lower Texas Coast on Monday as a result of the aforementioned
low.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             95  80  95  79 /  20   0  20  10
HARLINGEN               97  77  96  75 /  10   0  20  10
MCALLEN                100  80  98  79 /  10   0  20  10
RIO GRANDE CITY        100  78  98  78 /   0   0  10  10
SOUTH PADRE ISLAND      87  82  87  82 /   0   0  30  20
BAYVIEW/PORT ISABEL     91  80  91  79 /   0   0  30  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
TX...None.
GM...None.
-- End Changed Discussion --
&&

$$

SHORT TERM...23-Evbuoma
LONG TERM....66-Tomaselli
AVIATION...23-Evbuoma