Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 301741 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
1241 PM CDT Fri Sep 30 2016

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

&&

.AVIATION...VFR conditions will continue for the next 24 hours
as high pressure prevails over deep south Texas. Moderate
northeast winds this afternoon will become light and variable this
evening and overnight.

&&

.PREV DISCUSSION... /issued 354 AM CDT Fri Sep 30 2016/

SHORT TERM (Now through Saturday):  Atmospheric drying trend
continues today with driest air still upstream of the CWA to the
north. Surface dewpoints have already fallen to near 60 across
the northern ranchlands with values still near 70 in the Lower
RGV. Ridging aloft, with an axis aligned along the Rio Grande,
will dominate for most of the short-term, with surface high
pressure also in place. No mentionable chance of rainfall exists.

For the daytime on Friday, precipitable water values fall to
about 1.0" north to 1.5" south. Afternoon high temps will be just
a degree or so above normal, but with afternoon dewpoints falling
to the mid-60s even in the mid-Lower RGV, it should be a rather
pleasant day. Some mid-high clouds may spill over the top of the
ridge and stream by from time-to-time, but expect a lot of
sunshine overall. Friday night low temperatures will be in the
60`s most areas, apart from the coast where they will be in the
low 70`s.

Not much change as far as sensible weather for Saturday. However,
both NAM and GFS indicate that a weak, mid-level disturbance will
move through South Texas. Atmosphere will remain relatively dry
locally (though better moisture will reside not too far away to
the S and SW), so not expecting much beyond perhaps an increase in
cloud cover. Kept single-digit (silent) PoP`s in for now, but may
be able to drop these later.

LONG TERM (Saturday Night through Thursday): High pressure will
be in place across East texas and the Northwest Gulf at the
beginning of the long term. Weak, mid level ridging will be aloft
over the Southwest. The given pattern and associated general
weather won`t change much through the remainder of the weekend and
early part of the week. A deep, mid level low will drop south
along the Pacific Coast from the Pacific Northwest late in the
weekend, moving inland to the Great Basin on Monday. A cold front
will pick up some definition from the central high plains south
into New Mexico on Monday, becoming a pretty solid front moving
into North Texas Tuesday and Wednesday. From there, the GFS will
push the front more east than south, with drier air pushing into
central Texas on Wednesday, but not much farther. Southeast winds
will push back by Thursday, ending the dry air advance and pulling
moisture in from the Gulf. Mid level ridging will also build over
the area. The ECMWF, on the other hand, looks like it will push
some drier air into the area late in the week, but just after the
end of the long term.

With the slowly evolving scenario, went with a model consensus,
which introduced little change from the previous forecast. Rain
chances will be limited. Kept the mention of rain in the silent
category for much of the forecast. Temperatures will be much
closer to seasonal than previously, though still slightly above
normal, especially going into the meat of the work week, as a
warming trend ensues.

MARINE:
Now through Saturday...Light to moderate NE winds will persist
over the coastal waters through the period, courtesy of high
pressure over Texas. Seas remain at 3 ft. or less, therefore no
adverse marine conditions expected.

Saturday night through Tuesday...A broad, surface high pressure
pattern will generate light to moderate northeast to east winds and
low to moderate seas. As the supporting ridge aloft shifts east late
in the period, responding to a deep mid level low moving across the
West, the pressure gradient will reorient, veering local winds to
southeast Monday night as a front enters North and West Texas.

&&

.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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