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000
FXUS64 KBRO 191127 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
627 AM CDT Fri Apr 19 2024

...New AVIATION...

.SHORT TERM...
(Today through Saturday)
Issued at 129 AM CDT Fri Apr 19 2024

Above normal temperatures and generally rain-free conditions will
continue across Deep South Texas today through Saturday. A nearly
zonal flow aloft will continue to advect mid and high level
moisture over the region from the Pacific Ocean. At the surface,
persistent southerly to southeasterly flow will continue to bring
low level moisture into the region. The influx of low level
moisture and light winds have allowed patchy fog to develop across
portions of the northern Ranchlands and along the coast early
this morning.

Mostly cloudy skies early this morning will gradually clear
through the mid to late morning hours and with skies becoming
mostly sunny in the afternoon. Very warm to hot today with highs
ranging from the upper 70s along the beaches to upper 90s across
the Rio Grande Plains. Some convection will develop across the
higher terrain of Mexico and may drift southeast towards a more
stable atmosphere across the Rio Grande Plains later this
afternoon into this evening. The Storm Prediction Center /SPC/
included portions of Zapata County in a Day 1 general thunderstorm
outlook.

Another round of patchy fog will be possible late tonight,
especially near the coast. Lows will fall into the 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 upper
80s near the coast and the low to mid 90s elsewhere. Isolated
showers and thunderstorms are expected to develop across the CWA
Saturday afternoon, especially the northern Ranchlands and the Rio
Grande Plains, ahead of an approaching cold front. SPC has all of
Deep South Texas in a Day 2 general thunderstorm outlook, with a
Marginal Risk north of the CWA for Saturday.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 129 AM CDT Fri Apr 19 2024

Key message:
- Unsettled weather will occur Saturday and Sunday in the vicinity
of a transiting cold front

SPC depicts the local CWA in a general thunderstorm outlook area
both Saturday and Sunday.

Regarding Saturday, a shortwave trough will move toward the southern
Plains on Saturday, as zonal flow remains in place across much of
the Gulf Coast region. At the surface, a quasi-stationary front is
forecast to be located across south-central and southeast Texas.
South of this boundary, a moist airmass will be in place with
surface dewpoints in the 60s F. Surface heating will result in
destabilization across this airmass during the day. As instability
peaks during the afternoon, and as low-level convergence increases
along and near the front, scattered thunderstorm development is
expected.

ECMWF forecast soundings in south-central Texas during the late
afternoon suggest that MLCAPE will peak near 1200 J/kg, and that
0-6 km shear will be around 40 knots. This would be favorable for
an isolated severe threat. The stronger storms could be associated
with isolated damaging wind gusts and hail. However, limited
large-scale ascent and poor lapse rates will likely keep any
severe threat marginal and focused just north of deep South Texas
and the RGV.

Timing-wise, the front will move south across the CWA Saturday
night, pushing to the coast Sunday around dawn. Rain amounts
won`t be tremendous, maybe a few tenths for the luckier spots.
Moderate to breezy northeast winds will develop behind the front
Sunday through Monday. One consequence is that high temps Sunday
and Monday will be in the 70s. Saturday night lows will be in the
60s, cooling down a bit further Sunday night with a few mid to
upper 50s forecast for the RGV Plains and Ranchlands.

High pressure will spread over East Texas on Monday, with clouds
locked in over the area. The high pressure cell will shift farther
east on Tuesday, ahead of modest ridging just upstream. The old
front will be quasi-stationary just to the south.

Tuesday through Thursday, winds will shift to southeast, and temps
and relative humidity values will rebound as the old front lifts
north as a warm front, possibly sparking a few showers on Tuesday.
Winds could become a little breezier on Wednesday and Thursday as
high pressure interacts with pressure falls over the Plains.

&&

.AVIATION...
(12Z TAFS)
Issued at 621 AM CDT Fri Apr 19 2024

Low cloud decks with light and variable winds prevail across Deep
South Texas early this morning. MVFR ceilings are expected to
prevail through around mid-morning. VFR conditions will develop
later this morning into the afternoon. Low cloud decks with MVFR
ceilings are forecast to return later this evening with possible
IFR ceilings developing overnight.

&&

.MARINE...
Issued at 129 AM CDT Fri Apr 19 2024

Today through Saturday...Light to moderate southeast winds with wave
heights around 3 to 4 feet will prevail through the period. Small
Craft Should Exercise Caution conditions cannot be ruled out due to
a slight uptick in winds.

Saturday night through Tuesday night...Winds will decrease
Saturday night ahead of a cold front, which will move through
early Sunday morning. Shower and thunderstorm chances will
increase Saturday night ahead of the front. North winds will
become fresh to strong on Sunday after frontal passage, with
showers and thunderstorms in the area, both persisting through
Sunday night. Small craft advisory conditions will be likely.
Marine conditions will improve on Monday with light to moderate
southeast winds returning on Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             89  74  87  71 /   0  10   0  20
HARLINGEN               92  72  90  68 /   0  10   0  30
MCALLEN                 94  74  92  70 /   0  10   0  30
RIO GRANDE CITY         96  72  93  65 /   0  10  10  50
SOUTH PADRE ISLAND      80  74  79  70 /   0  10   0  20
BAYVIEW/PORT ISABEL     87  72  85  69 /   0  10   0  20

&&

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

$$

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