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FXUS64 KBRO 212337 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
637 PM CDT Wed Jun 21 2017

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

.AVIATION...Satellite images and surface observations indicate
mostly clear skies across the CWA early this evening. Expect VFR
conditions to prevail across the Rio Grande valley and northern
ranchlands tonight into early Thursday as tropical storm Cindy
continues to provide subsidence across the area as it moves
inland across extreme southeast Texas/southwest Louisiana tonight.
&&

.PREV DISCUSSION... /issued 341 PM CDT Wed Jun 21 2017/
SHORT TERM (Tonight through Thursday Night): Will not be make
many adjustments to the forecast with TS Cindy remaining on course
to make landfall near the Sabine River or the TX/LA border later
tonight. Model consensus moves the weak cyclone`s remnants across
East Texas Thursday farther away from Deep South Texas.

Main update this package is to extend the Coastal/Marine advisories
and statements.  Seas/Swells remain around 10 feet at Buoys 42020
and 42002 (200nm west of Brownsville). Expecting these swells to
peak this afternoon with a slow subsiding tonight and not until
Cindy moves inland would we see a more substantial lowering. High
tide occurs around 430am so another surge in tidal overwash is
possible overnight especially with tides running close to 2.5 feet
above normal.  We do not want to let our guard down and would favor
to exercise on the side of caution. So, the Coastal flood statement,
High surf advisory and small craft advisories, for the Gulf waters,
will be extended until 9 am Thursday.  The Rip current statement,
for a high rip current threat, will remain in place until 7 pm
Thursday but could be lowered earlier.

Temperatures are approaching forecast highs but could come up a few
degrees short with only 1-2 hours of heating left in the day. No
rain is showing up on radar this afternoon as dry air aloft
continues to mix to the surface. The next 36 hours are expected to
remain dry with still some subsidence and winds becoming west to
southwest in the morning keeping our dew points low and with no
appreciable increase in moisture through at least tomorrow
afternoon. Overnight, temperatures to slowly fall and could become a
bit comfortable with a slow recovery of humidity, an offshore wind
developing and clear skies allowing for temperatures to radiate
close to the dew points which will be in the lower 70s. This wont
last long with temperatures once again climbing fairly quickly after
sunrise with many locations still expected to exceed 100 degrees
Thursday. Latest model guidance remains bullish on temperatures and
forecast remains on the higher end of envelop. Later in the day
winds return to the south, as Cindy tracks northward, becoming
breezy in the afternoon which might also add to the afternoon
temperature surge. The pressure gradient remains strong overnight
with the southerly flow keeping temperatures slow to fall.
Temperatures might be quiet oppressive Thursday night with dew
points approaching 80 degree and a steady south wind overnight
minimums are not likely to fall below 80 degrees.

LONG TERM (Friday through Wednesday): 500mb ridge across the
southwest United States and northern Mexico will continue to
provide strong subsidence across southwest Texas Friday before an
inverted 500mb trough develops across the western Gulf of Mexico
Saturday and low to mid level moisture increases across the state
with moisture pooling along a weak frontal boundary moving into
north Texas this weekend and the moisture across the western Gulf
moving into south TX. This will provide an increasing chance of
showers and thunderstorms Saturday into Sunday and continue to
provide a chance of rain through the middle of next week as a
500mb trough across the eastern U.S. Sunday deepens Monday
allowing the front across north TX to move into south TX early
next week. This will allow moisture to pool along the front and
the weakness in the 500mb ridge across the western Gulf continues
through the rest of the forecast period.

Fire weather...Conditions remain dry and very hot today with
humidity levels in the 30 to 40 percent range, higher then expected.
Conditions to favor another modestly dry day on Thursday with winds
starting off light southwest in the morning. Winds may become an
issue later Thursday afternoon as the pressure gradient strengthens
as Tropical Storm Cindy moves inland across East Texas. Humidities
are still expected to crash with dew points remaining below seasonal
normal and will combine with temperatures rising well above 100.
Winds to combine with heat and lowering humidity with some areas in
the mid and lower valley possibly approaching red flag conditions
for a few hours. Will hold off on any Fire Weather Watch with
confidence on the timing of the strongest wind below average at this
time.

MARINE (Tonight through Thursday night): At 2 pm CDT, Buoy 42020
and 42002 both reporting ENE-NNE swells at 10 feet and 10 seconds.
Small craft advisories, mainly for hazardous seas, will be extended
through mid morning Thursday with swells expected to be slow in
subsiding. TS Cindy is forecast to move inland late tonight with
winds turning west to southwest which might allow for the swell to
subside quicker then expected, especially in the near shore waters.
For Thursday, expecting a brief lull in conditions as winds turn
southwest and sea subside through mid afternoon. Pressure gradient
is expected to strengthening late Thursday and Thursday night over
the Western Gulf as high pressure builds in behind the northward
moving remnants of Cindy. Models suggest winds reaching small craft
advisory levels which will allow for seas to build from the south.

Friday through Monday...Moderate to strong south winds will
prevail across the coastal waters Friday with low pressure across
west Texas and high pressure across the Gulf of Mexico. The
pressure gradient will weaken across the western Gulf Saturday as
a weak cold front moves into north Texas. Light to moderate
southeast winds Saturday will back to the east and diminish Sunday
as the front moves into central TX. Light east to northeast winds
should prevail across the lower TX coast Monday as the front moves
into south TX.
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through Thursday evening for TXZ251-256-
     257.

     High Surf Advisory until 10 AM CDT Thursday for TXZ251-256-257.

GM...Small Craft Advisory until 10 AM CDT Thursday for GMZ150-155-170-
     175.
&&

$$

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