245
FXUS64 KBRO 301138 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
638 AM CDT Tue Apr 30 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 232 AM CDT Tue Apr 30 2024

Low level moisture is surging inland as of this writing with WSR88-D
radar showing Isolated to scattered showers over the Lower Texas and
Tamaulipas coastal waters.  Some of these showers are spreading
inland this morning but mostly helping to steadily increase the
moisture content of the atmosphere across all of Deep South Texas.
Mean pwats of 1.7-1.9 inches are forecast over the region today and
Wednesday with increasing instability and a weak cap at best to
maintain a low chances (15-30%) of convection. A weak elongated
upper level disturbance moving across the south Texas this morning
initiates mid to late morning convection across the eastern two-
thirds of the County Warning Area (CWA).  The next shot of
convection is shown for Wednesday afternoon as a stronger
disturbance passes over South Central Texas placing the best chance
for thunderstorms over the NW portions of the CWA. At this time SPC
maintains a general thunderstorm outlook today and Wednesday.

Otherwise, plenty of morning and night time cloudiness with breaks
in the overcast for the afternoon hours. Temperatures continue to be
slightly elevated or above seasonal averages especially the
overnight night lows. Highs will range from 80 at the local beaches
through the 90s inland. Overnight lows only dip into the mid to
upper 70s. General moderate southeast winds with some gusts 0f 20-25
mph can be expected.

Finally, the rip current risk remains in the high category today
with a residual long period swell continuing to be directed towards
the Texas coast.  As the pressure gradient continues to weaken over
the Gulf the swell train should steadily subside over the next 12-24
hours.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 232 AM CDT Tue Apr 30 2024

The start of the long term forecast will have a tight pressure
gradient over Deep South Texas and the Rio Grande Valley as the
sustained winds could be around 15-20 mph with some stronger gusts
close to 30 mph for Thursday. The real interesting story for the
long term forecast period is what will the cold front do. An upper-
level trough over the Rockies will be the main driving force for the
cold front. By the end of the work week the cold front is expected
to stall out over Central Texas. While there is still a little bit
of a disagreement in the models on the timing of the front, the
models have shown a timing this past run that is a bit closer. Rain
chances remain very low through the period as a weak mid-level ridge
continues to exert its influence over the area. On top of that, the
middle and upper levels of the atmosphere are very dry so there is
no moisture aloft for showers and thunderstorms to build up with.

With southerly to southeasterly flow persisting over the long term
forecast period, warm and humid conditions are expected to be the
trend. High temperatures are expected to be in the range of upper
80s along the beaches to the mid 90s for most of the region. The
western parts of Starr, Zapata, and Jim Hogg could even be in the
upper 90s. Given the amount of humidity in the air and the heat,
future shifts will need to watch over the heat index values. As
maximum heat index values could be around 105 throughout the
period. As for the low temperatures, they are expected to remain in
the 70s for all of Deep South Texas and the Rio Grande Valley.

&&

.AVIATION...
(12Z TAFS)
Issued at 626 AM CDT Tue Apr 30 2024

Recent observations and satellite loops show breaks in the VFR-
MVFR ceilings across the regional airport early this morning. A
mix of VFR-MVFR should persist this morning with VFR becoming
predominate before Noon. There remains a low probability of a
showers or an isolated thunderstorm in the vicinity of the
air terminals late morning and afternoon. Lower MVFR ceilings
roll back into the region after sunset. Southeast winds to remain
light to moderate with gusts near 20 knots at times.


&&

.MARINE...
Issued at 232 AM CDT Tue Apr 30 2024

Tuesday through Wednesday...The pressure gradient continues to
weaken over the Gulf of Mexico with a 1020mb surface ridge
extending over the Eastern Gulf and lower pressure over NE Mexico.
Residual long period swells also are showing signs of lowering
with at least another 12-24 hours before the higher swell subside
below 5 feet. Local pressure gradient along immediate coast
tightens Wednesday with moderate to fresh southeast winds expected
over the Laguna Madre. There is a medium chance (40-60%) of a
Small Craft Advisory for the Laguna Madre Wednesday afternoon.

Wednesday Night through Tuesday..Adverse marine conditions are likely
with the tight pressure gradient over the Lower Texas Coast with
wind speeds around 15-20 knots. Thus a Small Craft Exercise Caution
is likely, but a low end Small Craft Advisory cannot be ruled out.
Moving into Friday and the weekend, more favorable conditions will
be present.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             89  77  88  77 /  30   0  10   0
HARLINGEN               90  74  91  75 /  30   0  10   0
MCALLEN                 92  77  92  77 /  20   0  10   0
RIO GRANDE CITY         93  75  93  77 /  20   0  10  10
SOUTH PADRE ISLAND      81  76  81  76 /  30  10  10   0
BAYVIEW/PORT ISABEL     86  74  87  75 /  30  10  10   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through this evening for TXZ451-454-455.

GM...None.
&&

$$

SHORT TERM...59
LONG TERM....64
AVIATION...59-GB