455
FXUS64 KBRO 182041
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
341 PM CDT Fri Apr 18 2025

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

.SHORT TERM...
(Tonight through Saturday night)
Issued at 338 PM CDT Fri Apr 18 2025

Throughout the short term, south-southwesterly to southwesterly flow
aloft will continue as a mid/upper level trough moves from
northwestern Arizona/southern Nevada to the Texas Panhandle by
Sunday morning.

At the surface, breezy to windy conditions are anticipated to
continue through Saturday night as a tightened pressure gradient
enhances south-southeasterly winds. Throughout this evening, wind
speeds across all of Deep South Texas will reduce down to 15-20 mph,
gusting up to 25-30 mph, with the higher winds west of I-69 E. The
gradient will set up another breezy day for Saturday, though a
slight bit less windy than today, as less robust height falls over
the Sierra Madre result from a decrease in 925-500 mb wind speeds,
as indicated by the latest GFS/NAM/ECMWF runs. At this time, the
likelihood of a Wind Advisory for Saturday is borderline;
probabilistic guidance holds a less than 15% chance of sustained
winds exceeding 30 mph throughout Saturday. A few gusts to 40 mph
are possible over the eastern part of the CWA, though the chance is
not as widespread and over a less than 2 hour timeframe in the
afternoon. Overnight Saturday, mixing heights decouple and winds
decrease to 10-15 mph with gusts to 20-25 mph.

As cloud coverage increases tonight and Saturday night, radiational
cooling will be limited and thus used CONSRAW to adjust overnight
temperatures a few degrees warmer for both nights, which brings
overnight lows into the lower 70s, which is about 4-5 degrees warmer
than average, and even warmer in some locations. Highs tomorrow
reach into the mid 90s along the US/Mexico border in Zapata County,
lower 90s across inland Deep South Texas, upper 80s for coastal
areas and upper 70s to lower 80s for SPI and Port Isabel.

A High Risk of Rip Currents at the local beaches continues through
Saturday night as a result of elevated winds and seas.

&&

.LONG TERM...
(Sunday through next Friday)
Issued at 338 PM CDT Fri Apr 18 2025

Loaded the NBM without modification. The tail end of a cold front
(part of a Plains system) will push into deep South Texas and the
RGV Sunday into Monday. The associated overhead mid-level trough
will bring enough instability into the picture to warrant a general
tstm outlook from SPC. I introduced a moderate chance (30-40%) of
convection into the forecast for both Sunday and Monday afternoons.

Another short wave trough over West Texas on Tuesday could interact
with a dryline extending south into Northeast Mexico on Tuesday,
introducing a chance (40-50%) of convection for primarily western
sections of the CWA as tstms develop over the Sierra Madre oriental.
Can`t rule out another isolated (10-20%) threat Thursday for the
western Brush Country/Upper RGV.

Additional hazards outside of the tstm threat will be minimal. Rip
current risk will likely fall into the moderate category through the
long term. The mid level pattern will remain zonal heading into next
weekend, and thus susceptible to destabilization from transiting
short wave troughs, but the next rain threat won`t occur until
beyond the end of this discussion period.

Temperatures won`t exhibit wide swings. Low temps will range from
the upper 60s to lower or mid 70s. High temps will start in the mid
to upper 80s, creeping into the lower 90s later in the week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1217 PM CDT Fri Apr 18 2025

Windy conditions continue through sunset, remaining VFR, as tight
pressure gradient enhances south-southeasterly winds to around
20-30 knots, gusting to 34-40 knots, till about sunset and
reducing 15-20 knots, gusting 25-30 knots overnight. Winds are
likely to remain enhanced a while longer at KMFE as well as remain
a bit breezier overnight as a low-level jet (925 mb) continues
overhead. As mixing heights lower tonight, MVFR ceilings return
and lower through sunrise, before rising to VFR and becoming
scattered as winds increase Saturday morning, though likely not as
strong as today.

&&

.MARINE...
Issued at 338 PM CDT Fri Apr 18 2025

Tonight through Saturday night...A tight pressure gradient will
continue to drive fresh to strong (18-23 knots) southeasterly to
southerly winds with strong to near gale force (24-29 knots) gusts,
resulting in moderate (5-8 feet) seas. A Small Craft Advisory
remains in effect till 7 AM Sunday morning as hazardous marine
conditions prevail.

Sunday through Wednesday night...Southeast winds will diminish to
moderate or fresh on Sunday, but small craft advisory conditions
(due to seas) may continue on the Gulf of America through Sunday
night or Monday. A weak front may stall over the CWA near the coast
Sunday into Monday, allowing moderate onshore winds to persist and
supporting a few coastal showers. As the front moves back north on
Tuesday, Gulf of America high pressure will build back and tighten
the gradient, so that late period onshore winds could again reach
small craft should exercise caution to low end small craft advisory
criteria by Wednesday night.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             72  88  73  87 /   0   0   0  30
HARLINGEN               72  90  73  89 /   0   0   0  30
MCALLEN                 72  92  73  89 /   0   0  10  40
RIO GRANDE CITY         72  94  72  87 /  10   0  10  30
SOUTH PADRE ISLAND      74  81  74  81 /   0   0   0  30
BAYVIEW/PORT ISABEL     73  86  74  86 /   0   0   0  30

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory until 7 PM CDT this evening for TXZ251-253>255-351-
     353>355.

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

GM...Small Craft Advisory until 7 AM CDT Sunday for GMZ130-132-135-
     150-155-170-175.

&&

$$

SHORT TERM...65-Irish
LONG TERM....54-BHM
AVIATION...65-Irish