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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KBRO 181112 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
612 AM CDT Thu Apr 18 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday)
Issued at 329 AM CDT Thu Apr 18 2024

Key messages:
- General to marginal severe weather threat later today for western
sections.
- Warmer than average.

High pressure will continue to dominate in the lower levels,
providing a steady southeast onshore flow. At 500 mb, the pattern
will be mostly zonal, but with a modest southwest flow ahead of a
short wave trough farther west. SPC included portions of the RGV
Plains, and Mid and Upper Valley in a Day 1 general tstorm outlook,
and included Zapata County in a marginal risk of severe weather
outlook. While a front moves south into Central Texas today,
igniting convection to our north, the threat to deep South Texas and
the RGV will likely come from the west (Sierra Madre Oriental
foothills). These storms, if they become strong, generally bring a
large hail and strong, potentially damaging wind threat. The window
for this threat, if convection drifts east toward and across the Rio
Grande, will be this afternoon to evening. The NBM was not carrying
much in the way convection, so introduced a mention. Skies will
remain mostly cloudy with moderate southeast winds and high temps
from the upper 80s east to the upper 90s west. Moderate risk of rip
currents.

Tonight will remain mostly cloudy with low temperatures in the lower
to mid 70s. Barring any lingering convection. The night should be
relatively calm. The severe weather threat for Friday will lie to
out north along the slowly approaching cold front. The models are
currently not bullish on precip for the CWA on Friday, although some
convection could develop once more over the Sierra Madre Oriental
front range to the west. The grids remain virtually barren for over-
area pops on Friday right now. High temps will again be above
average on Friday with a range similar to that expected today, under
mostly cloudy skies and moderate southeast winds.

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 329 AM CDT Thu Apr 18 2024

A nearly zonal flow aloft combined with surface high pressure will
maintain above normal temperatures and generally rain-free
conditions over the region Friday night and Saturday. Friday night
will be mild with overnight lows in the low to mid 70s under mostly
cloudy skies. Another very warm to hot day is expected on Saturday
with highs ranging from the 70s at the beaches, the mid to upper 80s
near the coast and the low to mid 90s elsewhere.

The weather pattern begins to change Saturday night with the
approach and passage of a weak cold front. Isolated to scattered
showers and thunderstorms are expected to develop along and ahead of
the frontal boundary. Convection is forecast to develop and move
into Rio Grande Plains and the northern Ranchlands Saturday evening
then across the Rio Grande Valley early Sunday morning.

In the wake of the front, cooler and drier air will filter into the
region Sunday and Monday with below normal temperatures. Highs on
Sunday will generally range from the upper 70s to the lower 80s
under cloudy skies. Lows Sunday night are expected to fall into the
60s areawide. Monday will be slightly cooler than Sunday with highs
in the 70s as easterly flow continues. The combination of an upper
level disturbance and increasing moisture may support lingering
isolated to scattered rain chances Sunday into Monday. Warmer
temperatures return Tuesday as surface high pressure slides eastward
and the frontal boundary lifts northward Tuesday into Wednesday.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 607 AM CDT Thu Apr 18 2024

MVFR conditions at the TAF sites now due to low cloud ceilings.
Mostly cloudy skies will prevail today with ceilings lifting out
mid to late morning. MVFR ceilings will develop again this evening
with patchy fog possible heading overnight into Friday morning,
but visibility will likely be no less than MVFR.
-- End Changed Discussion --

&&

.MARINE...
Issued at 329 AM CDT Thu Apr 18 2024

Today through Friday...Moderate southeast winds turning fresh on the
Laguna Madre in the afternoons. Small craft should exercise caution
then and there. Moderate seas.

Friday night through Wednesday...Generally favorable conditions are
expected to prevail through much of the period with light to
moderate winds and low to moderate seas. However, the passage of a
weak cold front Sunday morning may lead to Exercise Caution
conditions Sunday into Sunday night due to elevated winds. Isolated
to scattered showers and thunderstorms will be possible Saturday
night and Sunday with the passage of the front. Rain chances may
linger Sunday night into Monday with the passage of an upper level
disturbance.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             88  74  89  74 /   0   0   0   0
HARLINGEN               91  72  91  73 /   0   0   0   0
MCALLEN                 94  74  94  75 /   0   0   0   0
RIO GRANDE CITY         95  73  95  73 /  20  20   0   0
SOUTH PADRE ISLAND      79  73  79  74 /   0   0   0   0
BAYVIEW/PORT ISABEL     85  73  86  73 /   0   0   0   0

&&

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

$$

SHORT TERM...54-BHM
LONG TERM....63-KC
AVIATION...54-BHM