Brownsville, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

753
FXUS64 KBRO 220501 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1101 PM CST Sat Dec 21 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Sunday night)
Issued at 1259 PM CST Sat Dec 21 2024

A weak mid-level perturbation swings across Texas tonight through
Sunday night, with the surface ridge of high pressure edging
further offshore. This will turn light northeasterly winds
southeasterly into Sunday, increasing moisture, and combining
with the extra lift to build cloud cover across Deep South Texas
into Sunday night. Have kept POPs low, below 15 percent, but
higher than NBM across the CWA, especially the mid to lower
valley, for a few sprinkles or passing bouts of light rain Sunday
through Sunday night. Overall, most locations will remain dry and
cloud cover will help keep lows tonight and Sunday night warmer,
with highs tomorrow similar to today, near normal for late
December. With the increase in moisture and light winds, some
patchy fog may develop tonight, mainly across the ranchlands.

&&

.LONG TERM...
(Monday through next Saturday)
Issued at 1259 PM CST Sat Dec 21 2024

* Unseasonably warm weather will likely persist most of the week.
  Christmas Day should be quiet with well above normal temps
  ranging from the upper 70s to the mid 80s.

Inherited a solid forecast from the previous shift. Continued by
loading the latest NBM with few changes. The above average temp
trend remains integral to the model output. Looking back over the
last few days of the GFS output, despite some small element of
variability, model continuity has been quite consistent, providing
above average confidence in the temperature forecast. An NBM
reasonable worst case scenario for Brownsville is not large, 81
degrees + or - 4 to 5 degrees. This (2024) will certainly not be a
"white/cold" Christmas.

CPC`s (Climate Prediction Center) 6-10 day temperature outlook
now calls for a 70 to 90 percent probability of above normal
temperatures for deep South Texas. Thus, even though a cold front
will approach us on Christmas Eve, setting up light winds and a
night of fog (Santa may need the help of Rudolph`s red nose), the
front itself appears to only provide a glancing blow. Hence, the
Christmas Day forecast will feature unseasonably warm high temps
in the upper 70s to mid 80s. For reference, RGV high temps in
late December are typically in the lower 70s. Not only is it
nearly certain (90 to 100 percent) that we will see some high
temps 10 degrees above normal, there is a small chance (5 to 10
percent) that those high temps could reach 86 to 88 degrees, which
will be daily record territory for KBRO and KHRL. Forecast
soundings suggest that 925 mb temperatures will be 20 to 23C, near
maximum SPC sounding climatology for the Brownsville, TX upper
air site. With at least partly sunny skies expected, it might feel
more like early October than late December.

Boxing Day (December 26) might even get a skosh warmer than
Christmas Day itself, with high temps in the lower to mid 80s, but
for locations along and west of the I-69C/US-281 corridor
potentially pushing upper 80s to near 90 as a result of potential
downsloping, which would once again threaten record breaking high
temps. Closer to the coast and lower RGV, a weak disturbance that
is progged to lift northward from Veracruz into the Gulf of Mexico
could lead to isolated to scattered showers, mainly over the Gulf
but may also provide more cloud cover across our coastal zones.
Even without a trigger (weak disturbance), isolated Gulf showers
will be possible from time to time on established return flow.

A highly progressive upper level flow pattern consistent with a
positive NAO or lack of blocking over Greenland means that the
northern and southern stream remain separate. In other words, the
repeated shots of cold air infiltrating the Plains and Midwest
will be shut out of deep South Texas. Not surprisingly, the NAEFS
Ensemble Situational Awareness Table shows 1000-850mb temps 1 to
2 standard deviations above normal for the entire long term
forecast. Another cold front will approach on Friday, but the
timing details of the frontal passage and how cool it gets remain
uncertain.

&&

.AVIATION...
(06Z TAFS)
Issued at 1047 PM CST Sat Dec 21 2024

Predominantly VFR conditions are expected through the TAF period.
Ceilings will continue to drop overnight, and may briefly approach
MVFR levels by sunrise, however confidence remains too low to
include MVFR conditions in the TAFs. Ceilings will likely remain
near MVFR levels through the day Sunday, and may drop to MVFR
levels Sunday afternoon.

&&

.MARINE...
Issued at 1259 PM CST Sat Dec 21 2024

Now through Sunday Night...High pressure works further east,
turning light northeasterly winds southeasterly through the
remainder of the weekend. Generally favorable marine conditions
are expected to continue. A few sprinkles or passing light
showers are possible Sunday through Sunday night.

Monday through Thursday night...Look for mostly light to moderate
southeast to south winds and a light to moderate chop on the
Laguna Madre with moderate Gulf wave heights. The low key marine
weather forecast is predicated on the paucity of significant
weather systems moving into the area. Patchy fog may develop
pursuant to very light winds early Wednesday morning as an
extension of fog expected over land areas. A few showers may
develop from time to time in return flow along the coast.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             62  74  65  79 /   0  10  10   0
HARLINGEN               56  74  60  81 /   0  10  10   0
MCALLEN                 59  75  63  84 /   0  10  10   0
RIO GRANDE CITY         57  73  62  81 /   0  10   0   0
SOUTH PADRE ISLAND      67  73  69  76 /   0  10  10   0
BAYVIEW/PORT ISABEL     61  74  64  78 /   0  10  10   0

&&

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

$$

SHORT TERM...56
LONG TERM....54
AVIATION...60-BE