751
FXUS64 KBRO 210538 AAC
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1238 AM CDT Fri Jun 21 2024

...New AVIATION...

.UPDATE...
Issued at 930 PM CDT Thu Jun 20 2024

Blended models of most types are way overdone with inland rain
tonight. While we`ll still see passing sprinkles/light showers for
most areas, the sense of the weather will be partly cloudy with
diminishing winds...and tropically sultry (less yucky than it felt
earlier this month). Even the Gulf has largely quieted but expect
some uptick there after midnight. Bottom line? Deeper moisture is
exiting stage left...and have adjusted the forecast to account.
Updated text products will be sent shortly.

&&

.SHORT TERM...
(Tonight through Friday night)
Issued at 240 PM CDT Thu Jun 20 2024

Key Messages:

- Heavy Rain Potential continues tonight and Friday
- Overall Rain Chances Lower
- Coastal Flood Warning replaced by Flood Advisory tonight

In a nutshell tropical moisture remains elevated over the region
with scattered to numerous showers and isolated thunderstorms
continuing to track steadily and quickly westward. Pockets of heavy
with rainfall rates of 1-2 in/hr are noted with these shwrs/tstm but
with the quick pace flooding is not being observed. Tonight
convection should wane but not end with a continued chance of
additional convection Friday as differential  heating and
instability increases.  The National Blend of models (NBM) remains
rather stout on the PoPs over the next 24-36 hours so trended with a
more reserved CONSALL blend which shows 40-60 percent. Maintained
the mention of heavy rain through the period with forecast
precipitable water values in the 1.7-2 inch range. Pressure gradient
relaxes tonight as the remnants of former TS Alberto continue to
move west and dissipated over Mexico. Wind gusts should drop off
rapidly after sunset if not earlier with moderate east winds gusting
around 20 mph Friday due to a a general climatological onshore sea
breeze. Temperatures have recovered somewhat today with elevated dew
point pushing the heat index over 105 degrees for much of the CWA.
Warm and very muggy tonight and again Friday night with lows only 75-
80 degrees. Another typical hot day Friday with highs expected in
the low 90s and heat indices topping out 105-110 degrees.

Coastal flooding is forecast to ease slightly tonight as the tide
cycle approaches low tide around 830 pm.  Swells over the Gulf and
the off the lower Texas coast to remain elevated with a slow
subsidence through Friday. With the overall trend for lowering tides
the next 12-18 hours we will let the coastal flood warning expire at
7 PM and replace with an coastal flood advisory through Friday. With
this said, the combination of persistent elevated swells and with
tide cycle approaching high tide at 715 AM Friday some tidal
overwash exceeding the dune line on narrow beaches is possible early
Friday morning but this should be the exception to the rule.  Also,
Rip current risk to remain high with dangerous swimming conditions
tonight, Friday and Friday night.

&&

.LONG TERM...
(Saturday through next Thursday)
Issued at 240 PM CDT Thu Jun 20 2024

The long term period will feature continued precipitation chances
and near normal to slightly below normal temperatures across Deep
South Texas. Mid/upper level ridging will have shifted back over
the Southern Plains by Saturday, but all eyes will be on the
Southern Gulf of Mexico where another tropical system may develop
over the weekend or early next week. The latest deterministic
guidance indicates that should any system develop near the Bay of
Campeche, it would likely follow a track similar to Tropical
Storm/Depression Alberto and move west northwestward toward
Mexico. The National Hurricane Center currently has a 20% chance
of development through the next 48 hours, and a 50% chance of
development through the next 7 days.

Regardless of any tropical development, persistent southerly to
southeasterly flow will maintain a well established influx of
tropical moisture over Deep South Texas through mid week next
week. In combination with daytime heating during the late morning
and afternoon hours, isolated to scattered showers and
thunderstorms will develop over the weekend each day. Given the
beneficial rainfall we received with Tropical Storm Alberto,
additional rainfall may pose a threat for isolated instances of
flash flooding, especially in flood-prone areas. The latest
guidance indicates rainfall amounts through mid week will range
from around 0.75-2.5 inches, with higher amounts closer to the
coast.

&&

.AVIATION...
(06Z TAFS)
Issued at 1229 AM CDT Fri Jun 21 2024

Low clouds observed now, but conditions are VFR with moderate and
gusty east winds. An unsettled tropical air mass will support
isolated to scattered showers and thunderstorms today, and that is
reflected in the TAFs. Ceilings will be mostly low VFR with brief
MVFR possible. Winds will be moderate east, becoming light
tonight. The main aviation concern today will be lightning and
gusty winds from any nearby convection.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             91  79  90  79 /  80  70  90  80
HARLINGEN               91  74  90  76 /  80  70  90  70
MCALLEN                 91  77  90  77 /  70  60  80  70
RIO GRANDE CITY         90  75  88  76 /  80  60  80  50
SOUTH PADRE ISLAND      87  82  86  82 /  70  70  90  90
BAYVIEW/PORT ISABEL     90  78  89  79 /  70  70  90  80

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Coastal Flood Warning until 1 PM CDT this afternoon for TXZ351-
     354-355-451-454-455.

     Coastal Flood Advisory from 1 PM this afternoon to 7 PM CDT this
     evening for TXZ351-354-355-451-454-455.

     High Rip Current Risk through Sunday morning for TXZ451-454-455.

     High Surf Advisory until 7 PM CDT this evening for TXZ451-454-
     455.

GM...Small Craft Advisory until 7 AM CDT this morning for GMZ130-132-
     135.

     Small Craft Advisory until 7 PM CDT this evening for GMZ150-155-
     170-175.

&&

$$

SHORT TERM...54-BHM
LONG TERM....60-BE
AVIATION...54-BHM