000
FXUS64 KBRO 142342
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
642 PM CDT Mon Aug 14 2017

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

&&

.AVIATION...VFR to prevail tonight and Tuesday...just a few
cloud bands may produce periodic, but less than an hour of
MVFR ceiling anytime between 15/06Z-13Z. The pressure gradient
across South Texas and the Western Gulf of Mexico to remain
strong through Tuesday. Strong gusty winds up to 25 knots continue
through at least 15/02Z, this evening, with a moderate breeze
continuing overnight. Winds will be the lightest around sunrise
before daytime heating Tuesday allows for winds to increase once
again with sustained south to southeast winds of 20 knots gusting
to around 30 knots.

&&

.PREV DISCUSSION... /issued 242 PM CDT Mon Aug 14 2017/

SHORT TERM (Now through Tuesday Night): Broad mid-level ridging and
deep subsidence aloft will maintain above normal temperatures and
relatively dry conditions across deep south Texas through the
period. Low temperatures tonight will range from the upper 70s to
the lower 80s under partly cloudy skies. Slightly warmer
temperatures expected on Tuesday should support heat indices in the
109 to 113 range. A heat advisory may be needed for portions of the
area Tuesday afternoon. High temperatures Tuesday will range from
low 90s near the beaches to the triple digits generally along and
west of the I-69E/ Highway 77 corridor under mostly sunny skies. The
pressure gradient will strengthen on Tuesday resulting in breezy
southeast winds, especially along the coast. Low temperatures
Tuesday night will fall into the lower 80s across much of the
area.

LONG TERM (Wednesday through Monday): The dominate H5 ridge
stretched out over the Gulf of Mexico and southeastern U.S. will
slowly retrograde back over Texas and the Desert Southwest through
the end of the week. Some moisture may move westward around the
periphery of the ridge Wednesday and could bring a very small
chance for a shower. However, the atmosphere remains dry
throughout the mid levels and not much in the way of convective
activity is expected through the period. That being said, a
stray seabreeze shower could be hit or miss especially when winds
are light.

By the end of the week and through the weekend, the H5
high pressure will be settled over the region, with the hot and
mainly dry trend continuing for the RGV. Temperatures through the
long term period will easily remain in the triple digits for areas
near and along the I-69C corridor to as far east as the I-69E/HWY
77 corridor at times. Near and along the coast, highs will run in
the mid to upper 90s. The heat index values will remain in the
105-110F degree range, although a few hot spots in the Mid to
Upper Valley could briefly exceed 110F at times.

MARINE:

Now through Tuesday Night: Buoy 42020 reported south winds around
14 knots with gusts near 16 knots and seas of 3.6 feet with a
period of 6 seconds at 14 CDT/19 UTC. High pressure across the
eastern Gulf of Mexico will interact with heat-induced low
pressure across north-central Mexico. This will continue to
produce moderate to occasionally strong south to southeast winds
through Tuesday night. A Small Craft Advisory for winds remains in
effect for the Laguna Madre and nearshore Gulf waters (0 to 20nm)
through 9 PM. Small craft should exercise caution on the Gulf
waters tonight due to moderate winds. Small craft advisories will
likely be needed on the Laguna Madre and nearshore Gulf waters
again Tuesday with small craft advisories possible for all the
Gulf waters Tuesday night.

Wednesday through Saturday: A strong surface pressure gradient
will be in place across the Lower Texas Coastal waters on
Wednesday as high pressure over the eastern Gulf continues to
interact with low pressure inland. Moderate to strong SE winds
will remain elevated over the Laguna Madre and the nearshore Gulf
waters Wednesday with possible small craft advisories needed.
Seas will also come up as well, with 4 to 6 ft winds waves
expected. By Thursday, the gradient will weaken as high pressure
become more established over the Gulf with more light to moderate
winds and less agitated seas returning though the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  81  95  83  93 /   0  10  10  10
BROWNSVILLE          80  99  82  96 /   0  10  10  10
HARLINGEN            79 100  82  99 /   0  10  10  10
MCALLEN              80 105  82 101 /   0  10   0  10
RIO GRANDE CITY      79 105  81 103 /   0  10   0  10
SOUTH PADRE ISLAND   82  89  83  89 /   0  10  10  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory for winds until 9 PM CDT this evening for
     GMZ130-132-135.

&&

$$

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

59/99