National Weather Service Raw Text Product

269 
FXUS64 KBRO 132318 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
518 PM CST Tue Nov 13 2018

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...Low clouds have eroded away with influx of dry
northerly air. Deep moisture plume aloft from the southwest also
slowly eroding, so skies areawide should be clear by midevening,
and will continue through the rest of the night and all of the day
Wednesday.

&&

.PREV DISCUSSION... /issued 314 PM CST Tue Nov 13 2018/ 

SHORT TERM (Now through Wednesday night): Clearing line is half way 
through the CWA and continues to steadily move west to east in 
tandem with the 500mb trough axis. Models suggest the mid level 
trough axis to move along and east of the Texas coast by or shortly 
after sunset with clearing skies before midnight for the entire CWA. 
Brisk northerly surface winds remain elevated overnight but 
gradually lower as the cold surface high builds into South Central 
Texas. The ridge settles over South Texas and the Coastal Bend 
Wednesday with the cold air advection ending and full sunshine 
prevail during the day and clear skies Wednesday night. 

Main forecast challenge is how cold temperatures become tonight with 
now all counties expecting a light freeze with exception to the 
immediate coastal zones. Temperatures to drop off rapidly this 
evening especially in the RGV where limited heating took place today 
due to the persistent mid level cloud deck. With forecast soundings 
continuing to indicate cold air advection continuing overnight 
temperatures will continue to fall even with the elevated winds. 
Freeze warning remains in effect and has been expanded to include 
Inland Cameron county. Duration of the freeze is anticipated to be 
between 2 and 8 hours with the west and north seeing a longer 
duration. If winds diminish more than expected temperatures could 
reach freezing quicker and possibly extend the duration in some 
locations. The wind chill advisory also remains in effect overnight 
through 9 am as the persistent north wind combines with the falling 
temperatures. The minimal and relative short duration of the 
freezing temperatures and the relative cold wind chills should limit 
impacts to tender vegetation, people and pets that remain exposed to 
the elements for extended hours. 

Full sunshine and very dry air will allow for temperatures to 
rebound quickly Wednesday with most areas approaching or exceeding
60 degrees for nice refreshing day. High pressure settles 
overhead Wed night with clear skies and light winds setting up for
perfect radiational cooling to take place. Temperatures may 
approach freezing once again but at this time just have the 
portions of the Northern and Western Ranchlands approaching 32 for
a few hours. 

LONG TERM (Thursday through Tuesday): Northwest flow aloft will
move in across the Southern Plains behind a deep trough, which
helped bring in the last strong cold front. At the surface, high 
pressure will be positioned over Southeast Texas Thursday with 
lighter winds and cool temperatures expected across the region. 
Well below normal morning lows in the lower to mid 30s can be 
expected due to clear skies and light winds, and a few locations 
in the ranchlands may drop below freezing. The good news is that
the trend will be upward Thursday afternoon through the weekend 
with gradually-warming temperatures into the upper 70s through 
Sunday. Strong mid-level subsidence and dry air through the column
will also keep rain chances out and humidity values relatively 
low. Sunday night or Monday we may see our next cold front, which 
will bring increasing rain chances and cooler temperatures once 
again. Models indicate another coastal trough developing behind
the front, which would bring prolonged overcast skies, breezy 
winds and scattered showers. 

MARINE (Now through Wednesday night): Gale force gusts are waning
and are likely to end by 6 pm. A small craft advisory will 
replace the Gale warning and will likely persist through the day 
for the Gulf waters. For the Laguna Madre the SCA ends at midnight
but could last overnight for a few locations. High pressure 
builds along the coast Wednesday and Wednesday night with much 
improved conditions developing. 

Thursday through Tuesday: High pressure will spread over the area
early on, with steadily improving conditions across the coastal
waters. Light northerly flow will shift back to the southeast as
the high moves off to the east by the end of the week. The next
front may move through late this weekend, bringing adverse marine
conditions and increasing rain chances.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Freeze Warning from midnight tonight to 9 AM CST Wednesday for 
     TXZ248>255-353.

     Wind Chill Advisory from midnight tonight to 9 AM CST Wednesday 
     for TXZ253>255-353.

GM...Small Craft Advisory for winds until midnight CST tonight for 
     GMZ130-132-135.

     Small Craft Advisory until 3 PM CST Wednesday for GMZ150-155-170-
     175.

     Gale Warning until 6 PM CST this evening for GMZ150-155-170-175.

&&

$$

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