906
FXUS64 KBRO 150929
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
329 AM CST Fri Nov 15 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Today through Saturday)
Issued at 328 AM CST Fri Nov 15 2024

Mid-level ridging over the region initially, will move eastward
through the period as the next 500mb trough digs into the Great
Basin. At the surface, high pressure centered across the Middle
Mississippi Valley early this morning, will slide eastward today
through Saturday. Light easterly winds today will gradually become
southeasterly tonight into Saturday. Highs today will reach the mid
to mid 80s, except for the 70s at the beaches, under mostly sunny
skies. Lows tonight are expected to fall into upper 50s across the
Northern Ranchlands, the lower 60s across the Rio Grande Valley and
the upper 60s to the lower 70s at the beaches. Saturday will be
warmer with highs in the mid to upper 80s, except for the lower 80s
near the coast.
&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 328 AM CST Fri Nov 15 2024

The synoptic flow at the start of the long term forecast period will
see an upper-level trough moving into the desert southwest, which
will result in southwesterly flow in the upper levels for Deep South
Texas and the Rio Grande Valley. This will in turn lead to more dry
air in the upper levels of the environment that will hinder rain
chances for the early part of the long term forecast period.
Meanwhile, on the surface, a surface high pressure over the Mid-West
will continue to produce southeasterly winds providing warm air and
low-level moisture advection to the region. As the forecast period
progresses the surface high will continue to move eastward, as the
upper level trough drifts off to the east as well. Models do show
that the upper-level low associated with the trough will deepen as a
low pressure develops on the surface. As the trough moves towards
the region the pressure gradient is expected to tighten thus the
area could see some breezier conditions for Sunday and Monday.
Models in previous forecast runs indicated that a low-level jet
could also develop. If the winds were able to mix down to the
surface then that could result in the need for a Wind Advisory for
Deep South Texas and the Rio Grande Valley. However, confidence is
not high at this point, however, further forecast shifts should
continue to monitor the model trends.

By Monday, the upper-level trough and the cold front associated with
it will begin to approach Deep South Texas and the Rio Grande
Valley. Around Monday morning, the cold front itself is expected to
be pushing through Central Texas working its way southeastward. The
frontal boundary will become a convergence zone for moisture
allowing for the development of showers and thunderstorms ahead of
the front. At this time, the rain chances remain very low for most
of the CWA. The exception to this is along the coast where isolated
showers and thunderstorms as possible. However, it is still possible
that a rogue shower or two could pop up in other locations.
Currently, the best timing for showers and thunderstorms to develop
is in the afternoon on Monday, with lower chances during Monday
morning and night. As the upper-level trough moves towards the
northwest and the front pushes through the region by late Monday
night into Tuesday morning, the winds will shift towards the north
to north and become much lighter.

After, the cold front, a strong surface high pressure will move in
behind which will help to force more cold air into the area. This
area of high pressure will create some breezier conditions for the
region on Wednesday and early Thursday. The wind direction will
still be mostly out of the north, but will also become more
northwesterly as well. The winds themselves will start to diminish
on moving into Thursday afternoon, but will retain the same direction
out of the north.

As for the temperatures, which can be divided into before and after
the cold front. Before the front, high temperatures will range
between the upper 80s to low 90s for the region for Sunday and
Monday. Meanwhile, the low temperatures are a little bit more
varied in this period. Most of the region for Saturday night could
actually see low temperatures in the 60s, with a few places in the
Lower Valley in the lower 70s. Then, Sunday night lows are in the
70s for all of Deep South Texas and the Rio Grande Valley. With
Monday night as the cold front is pushing through, the low
temperatures are mostly in the 60s for the region. However, some
parts of the Upper Valley could see some lows in the upper 50s,
while the Lower Valley could still be in the lower 70s.

After the cold front pushes through, the high temperatures will be
mostly in the 70s for the rest of the long term forecast period.
With the lows starting off mostly in the 50s for Tuesday night.
However the temperatures will continue to cool as a strong surface
high pressure moves closer to the area, which will allow for the
overnight low temperatures for Wednesday and Thursday night to be in
the 40s.

&&

.AVIATION...
(06Z TAFS)
Issued at 1045 PM CST Thu Nov 14 2024

VFR conditions are expected throughout the TAF period, with clear
skies. Fog is not expected to develop, as the air is still too dry
from the cold front that passed through the area last night.  Winds
will start out predominantly northeasterly and move into a more
easterly direction throughout the TAF period.

&&

.MARINE...
Issued at 328 AM CST Fri Nov 15 2024

Today through Saturday...Favorable conditions will prevail along the
Lower Texas Coast through the period with high pressure in control.
Light east winds and low seas will continue today. Light to moderate
southeast winds are expected to return on Saturday as the pressure
slowly begins to strengthen. Low to moderate seas are expected on
Saturday.

Saturday Night through Thursday...Adverse conditions are expected to
start out the period as winds and seas become elevated due to an
enhanced pressure gradient ahead of a cold front that will push
through the Lower Texas Coast on Monday night into Tuesday morning.
By Sunday evening, Small Craft Advisories are going to be needed as
the winds become even stronger. Some wind gusts up to gale force are
possible, but currently there is not enough confidence in the need
for a gale watch at this point. Both winds and seas are expected to
remain hazardous until after the cold front pushes through the
region. After the front moves through, there will be a period of
more favorable of northerly winds and seas. However, as a strong
surface high pressure moves nearby, the southeasterly winds and seas
are expected to increase for Wednesday and early Thursday resulting
in more hazardous marine conditions that will require additional
Small Craft Advisories. By Thursday night, conditions will be
starting to improve and become more favorable by then.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             81  65  85  71 /   0   0   0  10
HARLINGEN               83  59  86  67 /   0   0   0  10
MCALLEN                 87  63  89  68 /   0   0   0   0
RIO GRANDE CITY         84  61  87  67 /   0   0   0   0
SOUTH PADRE ISLAND      78  73  81  76 /   0   0   0  10
BAYVIEW/PORT ISABEL     80  65  83  70 /   0   0   0  10

&&

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

$$

SHORT TERM...63-KC
LONG TERM....64-Katz
AVIATION...63-KC