FXUS64 KBRO 111731

Area Forecast Discussion
National Weather Service Brownsville TX
1131 AM CST Mon Dec 11 2023

...New AVIATION...

(Today through Tuesday)
Issued at 318 AM CST Mon Dec 11 2023

The short term period will feature slightly below normal
temperatures, increased cloudiness, and rain-free conditions.

Calm winds prevail early this morning across all of Deep South Texas
as surface high pressure settles along the  Texas coast. Winds
should begin to increase in speed (below 10 mph) and shift to the
southeast by mid to late morning as the surface high translates
east. Meanwhile, an mid/upper level trough will over Central Mexico
will translate toward South Texas through the day, placing the
region beneath southwesterly flow. As Pacific moisture is
transported northeastward, we should begin to see an uptick in cloud
cover by mid to late afternoon. The combination of return flow and
insolation should result in slightly warmer temperatures (although
still slightly below normal for mid December), with highs ranging
from the mid 60s across the Northern Ranchlands to around 70 degrees
across the Rio Grande Valley.

High res guidance continues to indicate persistent low level
southeasterly flow should result in the development of stratus
clouds across portions of the region tonight. Overcast skies should
result in warmer low temperatures tonight as cloud cover limits
radiational cooling processes, with low temperatures ranging from
the upper 40s to upper 50s. The mid/upper level trough will continue
to translate toward the Lower Texas coast into Tuesday, which should
result in the return of sunshine at least through early Tuesday
afternoon before mostly cloudy skies return. Highs will top out in
the 70s region wide.


(Tuesday night through Sunday)
Issued at 318 AM CST Mon Dec 11 2023

A coastal trough with some mid-level support and ample moisture are
expected to set up along the lower Texas coast Tuesday evening. PWAT
values should increase to around 1.5 inches by Tuesday night and
remain high through late week. The combination of these features
will lead cloudy skies and increasing rain chances through the first
half of the weekend.

A 500 mb over the Great Basin region Tuesday night will move into
southern Arizona and New Mexico Wednesday night into Thursday. The
best rain chances will arrive Thursday into Friday as the mid-level
low swings over north Texas and slowly moves eastward through the
rest of the long term period. Rain chances quickly diminish on
Saturday with the passage of the mid to upper level trough axis and
dry northwest flow aloft prevails. Near to slightly above normal
temperatures are expected Tuesday night through Thursday night due
to the increase in cloud cover and rain chances. Overnight lows will
fall into the 60s each night and highs Wednesday and Thursday are
expected to reach the low to mid 70s.

Surface high pressure will build into the region allowing for a
resurgence of cold air into the region resulting in falling
temperatures late week and into the weekend. Highs on Friday are
expected to range from the mid 60s to the mid 70 with lows Friday
night mainly in the upper 40s to the lower 50s. Cool to mild days
and chilly nights are expected for the weekend into early next week.

Finally, surface high pressure across along the northern Gulf Coast
will support a long fetch of easterly winds which will generate long
period swell across the northern Gulf of Mexico. This may lead to
minor coastal flooding and dangerous beach conditions along the
Lower Texas Coast, especially Wednesday into Friday.


(18Z TAFS)
Issued at 1127 AM CST Mon Dec 11 2023

High overcast VFR cloud deck prevail today and tonight, although
the high ceiling are expected to lower towards sunrise. As
moisture increases overnight another cloud deck between 4-5,000
feet is likely to develop around or after sunrise and potentially
lower during the latter half of Tuesday. Light east to southeast
winds prevail through the 18Z TAF package.


Issued at 318 AM CST Mon Dec 11 2023

Today through Tuesday...Favorable marine conditions are expected
through the period. Winds will shift to the east and southeast on
Monday as the surface ridge translates east, with seas around 2-3

Tuesday Night through Sunday...Adverse conditions are expected
to develop by Tuesday night as a coastal trough develops and
building easterly swell. Elevated seas and stronger winds will
lead to a long duration of Small Craft Advisories Tuesday night
through the weekend. The presence of the coastal trough will
support scattered to numerous showers and isolated thunderstorms
Tuesday night through the first half of the weekend.


BROWNSVILLE             69  58  74  65 /   0   0   0  10
HARLINGEN               70  54  74  62 /   0   0   0  10
MCALLEN                 69  54  72  62 /   0   0   0  10
RIO GRANDE CITY         67  51  71  61 /   0   0   0  10
SOUTH PADRE ISLAND      68  62  71  67 /   0   0   0  10
BAYVIEW/PORT ISABEL     68  57  73  63 /   0   0   0  10




SHORT TERM...22-Garcia