604
FXUS64 KBRO 061938
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
238 PM CDT Mon May 6 2024

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

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 224 PM CDT Mon May 6 2024

The big headline for the short term forecast will be the above
normal temperatures and the possibility of a heat advisory for
tomorrow during the afternoon. With zonal flow aloft and
southeasterly winds at the surface allowing for plenty of moisture
to move into the region tomorrow is expected to be hot and humid.
While the heat indices do get up to 112 which would be enough for
a heat advisory, the issue does come down to how long those heat
indices last. Currently, it does not seem like the timing
threshold is being met to issue a heat advisory at this point. An
SPS for the heat is also a possibility for if later shifts
continue to see this questionable trend on the timing. The actual
high temperature for tomorrow is expected to be mostly in the 90s.
Parts of Starr and Zapata could get into the triple digits, while
along the coast and the beaches the high temperatures are
expected to be in the upper 80s. It will be a hot day tomorrow so
make sure to take necessary precautions against the heat. Such as
staying hydrated, taking frequent breaks, and wearing light/loose-
fitting clothing.

For tonight and tomorrow night, the low temperatures are expected
to be in the 70s, with party cloudy to mostly cloudy skies. Humid
conditions are expected to persist through both nights thanks to
the onshore flow bringing in more low-level moisture.

For anyone that will trying to beat the heat at the beaches,
there is a Moderate Risk of Rip Currents through tomorrow.

&&

.LONG TERM...
(Wednesday through next Monday)
Issued at 224 PM CDT Mon May 6 2024

Heat will become more problematic at the beginning of the long
term. Temperatures have been running around 5 degrees above
average lately, but differences from average Wednesday through
Thursday could increase to a positive 10 degrees. A dryline will
set up shop just to the west, not penetrating very far into the
CWA, while at the same time moderate to fresh southeast breezes
will pump high dew point (in the 70s) air inland, placing an
upward stress on heat index values. Those heat index values could
range from 111 to 114 degrees for a few hours both afternoons, in
an area primarily sandwiched between I-69E and I-69C. Those heat
index values would trigger a HEAT ADVISORY. Drier air to the west
(remember the dryline?) will prevent heat index values from going
as high across the upper RGV, despite triple digit mercury
readings there.

The mid-level pattern will remain rather zonal most of the week, but
ridging will become more apparent heading into next weekend. Weather
systems will thus, for the most part, avoid this part of the world
through the week, yielding a dry forecast. Partly to mostly cloudy
skies will generally prevail, with increased sunshine taking over
each afternoon. Wildfire fuels are in transition (drying trend), but
do not see any obvious fire weather threat days just yet. Relative
humidity values will be in the teens and 20s out west Wednesday and
Thursday afternoons, but winds will be a skosh too light for
critical fire weather thresholds. Nonetheless, some enhanced
wildfire growth and spread will be possible.

A cold front will push into the area Friday morning ahead of the
building weekend ridge, with increasing clouds late Thursday,
possibly enough to trigger convection moving out of the Sierra Madre
Orientals and into the Upper Valley late Thursday evening lingering
into Friday. Scattered showers may develop and persist Friday and
Saturday as the front pushes offshore. By Saturday morning a coastal
trough will form with a warm front extending out from there into the
Gulf. Though the warm front will lose definition through Saturday, a
second (back door) cold front will push south over Texas on Sunday
providing a broader coverage of showery precip. Temperatures will
drop to near normal Friday through Sunday, warming again on Monday.
Rain amounts will not be overwhelming. The best chance of real rain
will be on Sunday with the second front when models suggest a
quarter to half inch of rain for the day.

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Mon May 6 2024

While mostly VFR conditions are expected through the afternoon at
all the TAF sites. MVFR conditions are expected to return tonight
and even some IFR conditions are possible during the overnight
hours as well. Some models hinted on the possibility of LIFR
conditions during the late overnight hours, but confidence for
them was low at this point. MVFR conditions are expected to return
for the morning hours tomorrow. Light southeasterly winds are
expected to persist at all the TAF sites for the TAF cycle.

&&

.MARINE...
Issued at 224 PM CDT Mon May 6 2024


Tonight through Tuesday Night...Mostly light to moderate
southeast winds with moderate seas are expected to persist through
Tuesday night. Small Craft Exercise Caution conditions are
possible during the afternoon hours with the winds picking up a
bit more, mostly for the Laguna Madre.

Wednesday through Saturday night...Moderate southeast to south
winds and moderate seas will initially prevail. Winds could
occasionally become fresh, and wave heights could occasionally
become slightly elevated, meaning small craft would then need to
exercise caution. Winds will shift to northeast on Friday as a
cold front pushes offshore. Isolated showers and thunderstorms may
develop on Friday and Saturday as a coastal trough forms after
the cold front passes through to offshore.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             78  93  78  95 /   0   0   0   0
HARLINGEN               75  96  75  99 /   0   0   0   0
MCALLEN                 77  98  78 101 /   0   0   0   0
RIO GRANDE CITY         76  99  76 103 /   0   0   0   0
SOUTH PADRE ISLAND      77  84  78  85 /   0   0   0   0
BAYVIEW/PORT ISABEL     76  91  76  93 /   0   0   0   0

&&

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

$$

SHORT TERM...64-Katz
LONG TERM....54-BHM
AVIATION...64-Katz