Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 210555 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1255 AM CDT Sun Apr 21 2019

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

&&

.AVIATION...Clear skies and southeast winds around 10 knots prevail
across deep south Texas early this morning. Breezy to windy south-
southeast winds will quickly develop by mid-morning as the pressure
gradient strengthens. Winds will gradually decrease to moderate
levels by late this evening. VFR conditions are expected for the
next 24 hours with high pressure in control.

&&

.PREV DISCUSSION... /issued 631 PM CDT Sat Apr 20 2019/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...VFR will remain in effect for the RGV terminals over
the next 24 hours as high-pressure ridging aloft maintains a
relatively dry atmosphere. SE winds expected to stay up around
10-12 knots overnight, as a surface low forms in the lee of the
Rockies. Stronger SSE winds develop rapidly for mid-morning on
Sunday as stronger winds just above the surface mix downward. High
cloudiness increases into tomorrow as well, with just a few lower
clouds around 025 overnight at the base of an inversion.

PREV DISCUSSION... /issued 346 PM CDT Sat Apr 20 2019/

SHORT TERM (Tonight through Sunday Night): Gorgeous weather
continues through the short term period for Deep South Texas. As
high pressure moves further east across the Gulf of Mexico, and
the mid-level ridge axis slides east, expect increasing
southeasterly winds and a few high clouds. The biggest concern in
the short term would be wind speeds across the lower RGV and lower
Texas coast for Sunday afternoon. A Wind Advisory may be needed
across at least Cameron County from late morning into the early
evening. Surf conditions along the local beaches of South Padre
Island and at Boca Chica Beach could potentially become hazardous
as well, with large crowds, from mostly inland locations, on hand.
Will continue to monitor the situation with help from SPI beach
patrol. Temperatures look to gain another degree or two tomorrow.
Low temperatures tonight and Sunday night remain in the mid to
upper 60s.

LONG TERM (Monday through Saturday): A pretty major 500 mb closed
low will push towards TX from the Desert SW on Mon and Tues
eventually moving across northern Mex and southern TX Wed and Wed
Night. This 500 mb trough/closed low will exit TX early Thur which
will usher through a fairly mild cold front through the region. In
the wake of this 500 mb feature, very dry and warm mid level
ridging will build in over the region on Fri and Sat maintaining
rain free conditions into next weekend.

Ahead of this approaching system the PGF will tighten up on Mon
with the strong gradient persisting into Tues Night. This
increasing southerly low level flow will bring in higher low level
dewpoints and increasing CAPE values early next week. SPC
continues to maintain an increased potential for svr wx over much
of south central TX for Wed and Wed Night. Considering the
strength of the approaching 500 mb trough and how far south it is
expected to dig around mid week, this increased svr wx potential
looks reasonable.

The ECMWF is faster with the eastward progression of this system
versus the GFS but is in general agreement in the strength and
depth of this system.

The temps and pops from the ECMWF and GFS are pretty good
agreement despite the timing differences indicated by both models.
Run to run consistency shown by both of the longer range models
are also pretty steady through Day 7/8. So will go close to a
model blend for both temps and pops in the longer range. Overall
forecast confidence is above average at this time.

MARINE (Now through Sunday Night): High pressure moves east across
the Gulf of Mexico through the short term, increasing southeasterly
onshore flow through the period. Windy conditions are expected along
the lower Texas coast on Sunday. Small Craft Advisory for Winds may
be needed across the Laguna Madre from the late morning to early
evening hours. Seas gradually build through the period, with Small
Craft Exercise Caution conditions likely across Gulf of Mexico
waters Sunday night.

Monday through Thursday Night...The strengthening PGF ahead of
the approaching 500 mb trough early next week will result in
stronger S/SE surface winds along the lower TX coastline for much
of the longer range marine forecast period. This may result in
borderline SCA conditions for Mon through Wed Night especially for
the lower TX Gulf waters. After the cold front moves through the
region, the PGF will then weaken allowing for lower winds and seas
Thurs/Thurs Night.

&&

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

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

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