Area Forecast Discussion
Issued by NWS Brownsville, TX

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070
FXUS64 KBRO 250023 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
723 PM CDT Wed May 24 2017

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

&&

.AVIATION...VFR conditions will prevail through the period with
mostly clear skies expected. Winds will increase and be gusty at
times Thursday as low pressure develops in the Southern Plains.

&&

.PREV DISCUSSION... /issued 241 PM CDT Wed May 24 2017/

SHORT TERM (Tonight through Thursday Night): 500mb ridge across
the central United States tonight will provide subsidence across
the state tonight into Thursday even as surface high pressure
across the Rio Grande valley moves eastward allowing an onshore
flow to return late tonight into Thurs morning. The pressure
gradient will increase across the lower Texas coast Thursday and
breezy conditions will develop across the coastal sections of the
CWA Thurs afternoon. Clear skies and light winds in combination
with the drier air across the area will provide relatively cool
temperatures tonight. With the onshore flow returning across the
Rio Grande valley tonight into Thursday...temperatures will be
near normal to slightly above normal Thurs afternoon and Thurs
night as a result.

LONG TERM (Friday through Wednesday): On Friday, the 500 hPa pattern
will flatten and support the lateral movement of a southern Plains
system toward the midwest. The local area of deep south Texas and
the RGV will remain under the influence of Gulf high pressure under
the western limb of the Bermuda ridge. Little change will occur on
Saturday with the dryline parked over the Big Bend area. On Sunday
a front will push south into central Texas as 500 hPa ridging builds
over the western United States. Intersection with the dryline will
spark Sunday night convection over the Big Bend region, essentially
the lower to mid Rio Grande Valley nomenclature on a national scale.
Temperatures through Sunday will trend higher, becoming several
degrees above normal. Look for a mix of clouds and sun through the
weekend, moderate to breezy southeast winds and high temperatures in
the 90s to a skosh above the century mark with low temperatures
well into the 70s if not near 80.

By Sunday, with a mean trough over the upper Midwest and ridging
again building over the western United States, high pressure will
spill southeast from the upper northwest United States, pushing into
central Texas. Convection will develop over the RGV Plains, upstream
from deep South Texas and the RGV. The front will approach the CWA
on Monday, with winds weakening and shifting to east, with some
uncertainty as to whether the front will have enough push to make it
through. At any rate, the atmosphere will be slightly destabilized
resulting in an increase in rain chances, particularly for the
northwest sector of the CWA, where convection may fire late Monday
night into Tuesday morning. Southeast flow will regain its footing
on Tuesday, with diurnal showers over the CWA and gently pushing the
frontal boundary back north.

MARINE (Tonight through Thursday night): Seas were near 4 feet
with north winds near 12 knots at buoy020 early this afternoon.
Winds will veer to the southeast across the coastal waters tonight
as high pressure across the Rio Grande valley and northeast Mexico
moves eastward. Light to moderate southeast winds tonight will
veer to the south to southeast Thursday and increase as the
pressure gradient increases across the western Gulf of Mexico with
low pressure across the Texas panhandle and high pressure across
the central Gulf. SCEC conditions will be likely across the
coastal waters with moderate to strong south to southeast winds
Thursday. Winds will increase offshore the lower TX coast Thurs
night and small craft advisories will likely be needed.

Friday through Monday night: Persistent high pressure over the Gulf
will combine with equally persistent lower pressure over the
southern High plains to produce moderate to fresh or low end strong
southeast to south winds and moderate to high seas through Sunday
night. Small craft should exercise caution to low end small craft
advisory conditions will be common through this period. The approach
of a cold front Sunday night through Monday night will weaken the
gradient allowing winds to become light east with lower seas.

&&

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

$$

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HTTP://WEATHER.GOV/RGV

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