914
FXUS64 KBRO 231129 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
529 AM CST Mon Dec 23 2024

...New AVIATION...

.SHORT TERM...
(Today through Tuesday)
Issued at 336 AM CST Mon Dec 23 2024

Guidance is showing that deeper moisture is being advected from
the SSE over the Rio Grande Valley due to an ongoing small upper
level disturbance in Central Texas.  As a result, there is a
10-15% chance of showers over the coastal counties through mid-
morning. Mostly cloudy skies are expected over most of the Rio
Grande Valley tomorrow, with areas in the western Ranchlands
seeing party cloudy skies. As the upper level disturbance moves
eastward towards Louisiana, skies should begin to clear a little
more this afternoon into evening with more partly cloudy skies
seen throughout the Valley.

Despite increased cloud cover, temperatures are expected
to remain significantly above normal both today and tomorrow, with
highs getting in the lower to mid 80s and lows getting down to the
lower 60s.  A moderate risk of rip currents are expected at local
beaches today, trending towards lower risks this evening into

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 336 AM CST Mon Dec 23 2024

- Temperatures remain well above normal through the end of 2024.

No changes for the long term with the weather pattern across the
CONUS remaining progressive with several shortwave troughs remaining
well north of Deep South Texas.  The general fast paced cyclonic
flow over the country continues to block any polar intrusions into
Texas and at the same time limit deeper moisture influx from the
south. With this said, temperatures will continue to build through
at least Saturday and rain chances will be limited to 10 percent or
less.  The National Blend of Models as well as deterministic and
ensemble guidance continue show maximum and minimum temperature
anomalies ranging 10-18 degrees above normal. Thursday and Friday
continue to look like the warmest days this week with next week and
even going into the last few days of 2024 highs and lows remain well
above average (even with a front knocking on the door next Sunday).
During this time period with the shortwave troughs trending farther
north with time and with the mid-level synoptic pattern trending
more zonal by next Sunday rain chances to trend below 10 percent. So
warm and dry is what the entire RGV and Deep South Texas region can
expect to close out 2024.  The Climate discussion below is a repeat
from yesterday`s AFD which list records and forecast for Xmas Even
and Xmas Day. More records may be listed as we go through the

&&

.AVIATION...
(12Z TAFS)
Issued at 524 AM CST Mon Dec 23 2024

VFR conditions are overall expected for the TAF period, with a
brief window of time between 12z-15z when BRO and HRL could see
intermittent periods of VFR and MVFR conditions due to cloud
ceilings. For this reason a tempo was added for these 3 hours for
possible MVFR. Winds could become gusty at all airports between
15z and 18z tapering around 02z, with southeasterly direction
expected throughout the entire TAF period.

&&

.MARINE...
Issued at 336 AM CST Mon Dec 23 2024

Today through Tuesday...Marine conditions are expected to be
overall favorable throughout the short term period. Seas between
3- 4 feet are expected, and winds are expected to be southeasterly
between 10 and 15 knots for both Nearshore and Offshore Gulf
waters.

Tuesday night through Sunday...Pressure gradient slowly strengthens
through Thursday as a mid-level storm system and it associated cold
front takes shape over the Southern Plains and North Texas. Moderate
to fresh winds with medium to high probability of Exercise Caution
messaging for Thursday. The storm system and front weaken and lift
north later Thursday and Friday with the latest model solutions
keeping the front well north of the Lower Texas coast. Pressure
gradient relaxes for the end of the week and into the weekend.

&&

.CLIMATE...
Issued at 336 AM CST Mon Dec 23 2024

The period from Monday through Saturday will feature temperatures 10
to 15 degrees above average, with the potential (a 10 to 20 percent
chance) for up to 18 degrees above from Christmas Day through
Friday. As for Christmas Eve/Christmas Day records? Despite the
warmth, records on these days are quite toasty - upper 80s near the
coast to lower 90s inland - and these markers should remain well in
hand.

Here are the records for Brownsville, Harlingen, and McAllen on
December 24 and 25:

Brownsville (since 1878): Christmas Eve Maximum: 87 in 1964.
Forecast: 83. Christmas Eve High Minimum: 73 in 1987. Forecast:  65.
Christmas Day Maximum:  88 in 2012. Forecast:  83.
Christmas Day High Minimum: 70 in 2016.  Forecast: 68.

Harlingen (since 1912): Christmas Eve Maximum: 87 in 1964. Forecast:
82. Christmas Eve High Minimum: 73 in 1987. Forecast:  63.
Christmas Day Maximum:  89 in 2015. Forecast:  83.
Christmas Day High Minimum: 73 in 2015.  Forecast: 67.

McAllen (since 1942): Christmas Eve Maximum: 92 in 1948. Forecast:
85. Christmas Eve High Minimum: 72 in 1987. Forecast:  64.
Christmas Day Maximum:  92 in 1964. Forecast:  86.
Christmas Day High Minimum: 72 in 2015.  Forecast: 68.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             79  65  80  66 /  10   0   0   0
HARLINGEN               81  60  82  62 /  10   0   0   0
MCALLEN                 83  64  85  64 /   0   0   0   0
RIO GRANDE CITY         81  61  84  60 /   0   0   0   0
SOUTH PADRE ISLAND      76  69  76  69 /  10   0   0   0
BAYVIEW/PORT ISABEL     78  64  79  64 /  10   0   0   0

&&

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

$$

SHORT TERM...55-MM
LONG TERM....59-GB
AVIATION...55-MM