Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 141755 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1255 PM CDT Sat Apr 14 2018

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

&&

.AVIATION...VFR conditions will prevail for the next 24 hours.
Breezy north winds will continue this afternoon as high pressure
builds into the region. Winds will diminish and become light late
this evening and overnight as high pressure settles across the
area.

&&

.DISCUSSION...Updated for latest marine discussion below.

&&

.MARINE...Recent marine observation platforms indicate frequent
gale force gusts are occurring over the offshore Gulf waters.
Have decided upgrade the previous SCA and issued a Gale Warning
for the Gulf waters 20 to 60 NM out through 4 pm this afternoon.
No other changes needed at this time.

Thanks for the coordination WFO CRP.

&&

.PREV DISCUSSION... /issued 615 AM CDT Sat Apr 14 2018/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...A cold front is moving through now with strong, gusty
north winds and isolated to locally scattered rain showers. Radar
shows the post frontal convective cells weakening and breaking up
as the main frontal boundary front pulls away and offshore, while
cooler and much drier air starts to filter in from upstream.
Multilayered low clouds are present, with MVFR ceilings, and the
clearing out process will last through mid morning, but ceilings
will lift to VFR within the next few hours. Winds will continue
to be breezy and gusty from the north today.

PREV DISCUSSION... /issued 437 AM CDT Sat Apr 14 2018/

.Breezy to Windy and Much Drier Today Followed By a Near
Perfect Sunday...

SHORT TERM (Today through Sunday): A cold front is currently moving
through the area and offshore, bringing much drier and relatively
quiet weather. Will need to endure a few hours of strong north winds
and windy conditions today, however, and a short duration wind
advisory could still be in the cards. High temperatures will be
milder today, in the upper 70s to lower 80s, but will dive into the
upper 40s to lower 50s under clear skies tonight, with light winds.
High temperatures on Sunday will be back into the 80s except right
along the coast which will stay in the mid to upper 70s, with sunny
skies and light to moderate winds shifting from northeast to east
and southeast during the day, the result of high pressure spreading
over the area in the wake of the cold front.

LONG TERM (Sunday Night through Friday): Only subtle changes to
the forecast for the upcoming workweek...mainly for a bit more
increase in wind sooner and a rise in temperature to match the
warmer ECMWF which has been outperforming the GFS during dry and
mostly sunny conditions. In the big picture, northern extent of
broad and flat subtropical ridge centered across central Mexico
dominates the pattern through Wednesday. The ridge pokes further
north Thursday into Friday before dampening down a bit Friday
night as yet another mid latitude trough shifts from the Rockies
into the southern and central Plains by next Saturday.

As for sensible weather...Monday dawns pleasant with light east
southeast winds...though there looks to be enough wind to keep
temperatures from falling too much before daybreak so ranging
through the 50s looks to be a good call. Plenty of sunshine
Monday with a quickly freshening southeast wind will pump
temperatures back to or slightly above average in most areas...and
raised values to be in line with the ECMWF which is handling these
situations best. Tuesday brings the Wind Machine to favored areas
east of US 281/IH 69C as the first deepening surface low scoot
through the southern Plains and baggy trough along the Sierra
Madre kicks low level average wind speeds to or above 35 knots.
with still plenty of sunshine for excellent mixing situation could
be on the edge of Wind Advisory (30 mph and gusty) but for now
capped winds in the 25-28 mph sustained as we have time to iron
out the details. Temperatures will reach the upper 80s to lower
90s area-wide as the atmosphere warms.

Wednesday should continue breezy to windy (near the coast) with
still mainly sunny skies. A surface "bubble" ridge scoots by to
our north as the aforementioned 500 mb ridge pokes north. This
will diminish winds and back them to the east for Wednesday night
and Thursday though some breeziness will continue. The easterly
flow will bring a bit more moisture so expect partly cloudy
conditions along with a slight lowering of temperatures...still
near to just above average (average ranges from the lower 80s
toward the coast to the upper 80s mid/upper Valley). For Friday,
southeast flow picks up in earnest though cloud cover may help
mitigate potential for wind advisory. As for
precipitation...models not too bullish on significant QPF and once
again the best plume favors locations north of the RGV...so kept
just a 20 percent mention for mainly the ranchlands both Thursday
and Friday.

MARINE: Small craft advisory conditions will prevail
today in the wake of a cold front, with strong north winds and high
seas. Conditions will settle down to below criteria on the Laguna
this evening, but advisory conditions will continue on the Gulf
through tonight while seas remain high. High pressure will spread
over the area through Sunday, with improving marine conditions.

Sunday Night through Wednesday Night: Continued steady improvement
for winds and seas will make for ideal boating and fishing
conditions early Monday morning. But the window will be short...by
afternoon Laguna Madre will become choppy and winds may approach
20 knots so caution may need to be exercised. Monday night through
early Wednesday brings increasing likelihood for 20 knot and gusty
winds through the well mixed atmosphere, with the Laguna most
likely by day and the Gulf by night. Some decrease in winds is
likely Wednesday into Wednesday night. Seas will also rise and
could touch 7 feet overnight Tuesday into early Wednesday before
slowly subsiding Wednesday night. ECMWF a bit higher on winds
overall and wavewatch model which basis is the GFS may be
underdoing seas a bit...a trend we`ll be watching through early
next week.

FIRE WEATHER...Today: Dry air will continue to move into the
region from the west today in the wake of a cold front, along
with the development of moderate to strong 20 ft north winds. A
red flag warning is up for the inland counties today. Should drier
air push strongly to the coast, critical fire weather conditions
may be reached in the coastal counties as well, and the red flag
warning may be expanded. Will issue a fire danger statement for
the coastal counties for the time being.

Monday through Tuesday: With dry to critically dry fuels solidly
in place especially along and west of US 281/IH 69C, stage is set
for continued erratic wildfire behavior and perhaps rapid growth
each afternoon. Monday offers the higher potential as model trends
are increasing southeast wind speeds close to or just above 20 mph
while afternoon humidity falls to between 20 and 25 percent in
some areas, which would be sufficient for Red Flag conditions.
Tuesday`s humidity rises a hair but winds do as well, and
potential for 25 mph and higher wind with inland RH between 25 and
40 percent is on the table which would also meet Red Flag
conditions as fuels will remain dry to critically dry.

Conditions should improve Wednesday with some diminishing winds
by afternoon and increasing humidity, but fuels should remain dry
until even higher humidity arrives by Thursday.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Red Flag Warning until 7 PM CDT this evening for TXZ248>250-252-
     253.

GM...Small Craft Advisory for winds until 7 PM CDT this evening for
     GMZ130-132-135.

     Small Craft Advisory from 4 PM this afternoon to midnight CDT
     tonight for GMZ170-175.

     Gale Warning until 4 PM CDT this afternoon for GMZ170-175.

     Small Craft Advisory until midnight CDT tonight for GMZ150-155.

&&

$$

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