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000
FXUS64 KBRO 212332
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
632 PM CDT Sun Apr 21 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Monday night)
Issued at 239 PM CDT Sun Apr 21 2024

Elevated instability, weak mid-level frontogenesis, weak
overrunning/isentropic upglide, and deep moisture to 600-650 mb will
be sufficient to keep precipitation in the forecast for tonight.
Could see a few thunderstorms as well. Generally went with slight
chance to chance POPs for the CWA for tonight with the highest POPs
across the populated RGV.  This is generally in line with most CAM
and synoptic scale guidance. Temperature advection has nearly ended
behind the cold front which pushed through earlier this morning.
Thick cloud cover will tend to limit diurnal cooling tonight.
However we are still anticipating upper 50s for most of the Northern
Ranchlands and the Upper Valley with lower to mid 60s elsewhere
except upper 60s along the islands.

A mid/upper closed low near Baja California presently will track
across our CWA on Mon albeit it will be shearing apart.  This
additional dynamical forcing and the still deep amount of moisture
to around 600-650 mb will warrant another round of precipitation on
Mon.  Once again, we could be looking at a few embedded
thunderstorms as well given the elevated instability.  NBM POPs were
too low for Mon and raised these to the 20-40% level for the entire
CWA.  Again, the highest POPs were across the populated RGV. Most of
the precipitation is expected to end from west to east by Mon
evening as the closed low/shortwave moves east of the CWA.  Other
than perhaps a brief sprinkle or some patchy drizzle, conditions
should remain mostly dry for Mon night.

Highs on Mon will remain well below normal by around 10-15 degrees
given the thick cloud cover and post-frontal airmass remaining in
place. A little bit of moderation but still cooler than normal
overnight lows is expected on Mon night.

A High Risk of Rip Currents will remain through Monday given the
persistent large seas and long periods.

&&

.LONG TERM...
(Tuesday through next Sunday)
Issued at 239 PM CDT Sun Apr 21 2024

A building mid-level ridge passing over Texas Tuesday through
Thursday followed by a developing large scale upper trough over
the western third of the CONUS will result in a warming trend
along with increasing southerly winds. Latest deterministic and
ensemble model trends are on board with temperatures climbing from
slightly below normal Tuesday, at normal Wed and Thurs to well
above normal Friday through next weekend. This will push daytime
maximums well into the 90s inland with lower to mid 80s at the
beach. Low temperatures look to rise into the lower to mid 70s
through the week. No fronts are on the horizon with the upper
troughs remaining well to west or passing well north of Deep South
Texas. Southerly flow looks to be on the increase as the pressure
gradient tightens between surface ridge over the Gulf and a
series of low pressure areas along the Sierra Madre through the
Southern and Central Plains. Strongest winds at this time look to
occur Thursday through Sunday when afternoon gusts could reach
35-40 mph mainly over the typical windy locations of the Lower
RGV.

&&

.AVIATION...
(00Z TAFS)
Issued at 632 PM CDT Sun Apr 21 2024

MVFR/IFR ceilings will prevail through the TAF period at all TAF
sites with periods of SHRA and isolated TSRA. The latest radar and
satellite imagery depicts a dense blanket of post-frontal stratus
across Deep South Texas and pockets of elevated showers this
evening. Expect widely scattered showers to persist through late
this evening north of the TAF sites, with an uptick in activity
after 06-08Z through 12-14Z. Additional convection is expected
throughout the day on Monday as an upper level system approaches
from the west. Isolated TSRA cannot be ruled out, but confidence
in location and timing is too low to warrant a mention in the TAF
at this time. Otherwise, north winds will gradually shift to the
northeast through tomorrow afternoon with speeds generally below
10 knots.

&&

.MARINE...
Issued at 239 PM CDT Sun Apr 21 2024

Tonight through Monday night...Strong N/NE winds and building seas
will maintain Small Craft Advisory conditions through this evening
across the Laguna Madre and through Mon morning for the remainder of
the coastal waters.  Winds and seas will peak over the next several
hours and then slowly diminish and subside as the gradient and CAA
weaken.  This weakening trend will persist through the remainder of
the short-term forecast period as high pressure slowly shifts
eastward.  Onshore flow will begin developing late in the day on Mon
as a result.

Tuesday through Sunday: The Lower Texas coastal waters can expected
improving conditions Tuesday and Wednesday as surface high
pressure gradual tracks eastward and mid-level high pressure
remains over Texas. Pressure gradient begins to tighten Thursday
continuing to strengthen Friday and next weekend as the
interaction between modest surface ridge over the Gulf of Mexico
and a series of low pressure area over NE Mexico and the Southern
Plains develops. Light to moderate southeast winds return to the
coastal waters Tuesday and Wednesday with fresh to occasional
strong onshore flow Thursday through Sunday. Mariners can expect
seas to remain slight to moderate through midweek before
increasing over the weekend. Periodic Small Craft Advisories for
all or portions of the Lower Texas coastal waters Thursday through
Sunday are possible.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             65  74  66  82 /  40  40  10  10
HARLINGEN               62  74  62  83 /  30  40   0  10
MCALLEN                 62  74  63  84 /  40  40   0  10
RIO GRANDE CITY         59  72  61  83 /  40  40   0  10
SOUTH PADRE ISLAND      68  72  69  78 /  30  40  10  10
BAYVIEW/PORT ISABEL     65  74  66  81 /  30  40  10  10

&&

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

GM...Small Craft Advisory until 10 PM CDT this evening for GMZ130-132-
     135.

     Small Craft Advisory until 7 AM CDT Monday for GMZ150-155-170-
     175.

&&

$$

SHORT TERM...80
LONG TERM....59
AVIATION...22-Garcia