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000
FXUS64 KBRO 172315 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
615 PM CDT Wed Apr 17 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Thursday night)
Issued at 254 PM CDT Wed Apr 17 2024

The biggest story for the short term forecast period will be the
above normal temperatures that will affect Deep South Texas and the
Lower Rio Grande Valley. A mid-level ridge will continue to
influence the region. While some tiny showers and thunderstorms did
get going this morning in the Lower Rio Grande Valley, SPC does have
the far western parts of Starr and Zapata in a general thunderstorm
outlook. A mid-level short wave will allow for some instability over
the Sierra Madre that could allow for some convection to grow there
and could perhaps move into the CWA. Although the PoPs are barely
mentionable and the rest of the environment does not appear to be
super favorable for any convection to make it that far. However,
cloudy conditions are expected to continue through the short term
period. As low level moisture continues to move into the area thanks
to the southeasterly flow at the surface. Also due to this moisture
flow, fog over the island and coastal areas is also possible
tonight. A moderate risk of rip currents is still in play today
through tomorrow.

Moving into Thursday, SPC does have the northwestern part of the CWA
in a marginal risk, while part of Middle Rio Grande Valley is in a
general thunderstorm outlook. However both PoPs and QPF remain very
low for going into tomorrow and the mid-level ridge still has some
influence over the region that will hinder the development of
showers and thunderstorms.

&&

.LONG TERM...
(Friday through next Wednesday)
Issued at 254 PM CDT Wed Apr 17 2024

Key messages:

* Showers and thunderstorms possible Saturday night into Sunday

* Cooler and drier airmass change coming behind a cold front Sunday
  and Monday

The main weather concern during the long-term forecast period
continues to evolve around the risk for showers and thunderstorms
Saturday into Sunday as a cold front attempts to sweep through the
region.

On the western flank of a sfc high pressure system and ridge axis,
southerly winds will help to keep a very warm and humid airmass in
place over region Friday through Saturday. Dry and tranquil
conditions will also persist with continued influences from the
aforementioned sfc high and higher heights.

Attention then shifts to Saturday night into Sunday as deterministic
forecast models and ensembles continue to advertise the potential
for showers and thunderstorms developing along/ahead of a cold
front. With the given dynamics/ingredients in place, should all else
hold, there could be the potential for some of these storms to
become strong to severe. Will continue to monitor trends in the
hours/days ahead.

Behind the cold fropa, a notable cooler and drier airmass change
will take form Sunday and Monday. Instead of highs in the upper 80s
to mid 90s as we`ll see through Saturday, daytime highs are progged
to be in the lower 80s (70s near/along the coast). Meanwhile,
dewpoints are expected to be in the 60s as opposed to the lower
70s. Overnight low are forecast to be in the 60s Sunday night and
Monday night.

Tuesday through Wednesday, the warmth and humidity are expected to
return again as a frontal boundary attempts to lift north of the
area.

&&

.AVIATION...
(00Z TAFS)
Issued at 608 PM CDT Wed Apr 17 2024

MVFR conditions will prevail this evening at BRO and HRL while
VFR conditions are expected at MFE. Later this evening ceilings
will lower across the regions with both BRO and HRL falling to
IFR. HRL should hang onto MVFR a bit longer than BRO. MVFR
ceilings will move into MFE, most likely after midnight. Both BRO
and HRL will see ceilings lift mid to late morning with VFR
returning by midday and VFR returning to MFE by midmorning.
Southeastern winds will remain moderate.

&&

.MARINE...
Issued at 254 PM CDT Wed Apr 17 2024

Tonight through Thursday Night...While generally favorable
conditions are expected through Thursday night with moderate
southeasterly winds and waves. Some stronger winds are possible over
the Laguna Madre that could require Small Craft Exercise Caution at
times.

Friday through Wednesday...Favorable marine conditions are expected
to prevail through the long-term period with light and moderate
winds and seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             73  87  74  89 /   0   0   0   0
HARLINGEN               71  91  72  91 /   0   0   0   0
MCALLEN                 75  93  75  94 /  10  10   0   0
RIO GRANDE CITY         74  95  73  96 /  20  10   0   0
SOUTH PADRE ISLAND      73  79  74  80 /   0   0   0   0
BAYVIEW/PORT ISABEL     72  86  72  86 /   0   0   0   0

&&

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

$$

SHORT TERM...64
LONG TERM....23
AVIATION...68