Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 010830
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
330 AM EST Thu Dec 1 2016

.SYNOPSIS...
Drier and cooler conditions are in store for today, and will
persist through Saturday. Moisture should return from the west for
the latter half of the weekend and possibly linger into early next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 245 AM Thu: The surface cold front appears to be aligned
over the easternmost tier of counties in our CWFA, and should have
exited the area by sunrise. Some upslope clouds will persist near
the Tenn border into the day, but otherwise mostly sunny skies
are expected. Breezy conditions will occur over the mountains (and
occasionally elsewhere too) under cold advective flow. Max temps
will be a category or so above normal, with downsloping offsetting
the CAA a bit. Calmer and still mostly clear conditions tonight
imply good radiative cooling; mins will be close to normal.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 315 AM EST Thursday: the end of the week looks quiet enough,
for the most part. Nearly zonal flow aloft will gradually buckle as
an upper ridge slowly amplifies to the west on Friday and Saturday.
This will support dry high pressure over the Southeast on Friday
that gradually gets assimilated by another surface high coming
across the Plains on Saturday. Temps both days will be very
similar...slightly below normal.

Changes will take place Saturday night as the upper ridge axis moves
overhead. Expect isentropic lift to spread northeast across the
region along with moisture return from the Gulf, aided by upper
divergence from the right entrance region of a jet streak passing to
the north. Expect that precip will attempt to develop from the west,
at least across the mountains and wrn half of the fcst area in the
pre-dawn hours on Sunday. Think we can fine tune the timing a bit,
based on the SREF and GEFS, to keep precip chances from moving in
until after 00Z Sunday, and to delay the eastward expansion of
likely precip until after 12Z Sunday. Temps are problematic as
initial dry air will allow for boundary layer cooling. Fcst
soundings, in particular the NAM, suggest that precip will reach the
ground as snow at elevations above about 3K feet around daybreak
Sunday, altho the GFS is not as cool. Think a compromise is in order
that would result in some snow chance at elevations above about 3500
feet if precip develops after midnight, but for the time being no
accumulation is expected as precip amts are minimal.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 225 AM EST Thursday: the medium range fcst picks up at 12z on
Sunday with flat upper ridging in place over the southeast and a large
H5 cutoff low over NW Mexico. This low eventually becomes absorbed by
the mean flow and morphs into a decent looking shortwave. The models
have the shortwave passing just to our NW on Tuesday as the upper ridge
steadily amplifies. Ridging is expected to remain in place until the
end of the period with a broad upper trof approaching the fcst area
late in the week. At the sfc, the pattern evolution remains somewhat
uncertain compared to the upper levels. The models are delaying the
development of a Northern Gulf of Mexico low until Monday/Tuesday with
the system not moving to our north until late Tuesday. In the wake of
the low, things dry out on Wednesday. Another cold front appears to
approach the CWFA from the west by the end of the period on Thursday,
but timing varies between the models.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
At KCLT: Winds are taking their time to veer in the wake of the
front; expect a shift to WNW by daybreak. Lee troughing appears
likely to bring winds back to WSW for a time there this aftn.

Otherwise: VFR as colder/drier air filter in on W to NW winds;
some upslope cloudiness will linger over the mountains this
morning. Where winds remain more westerly, they should veer more
NW this evening. Some occasional gustiness is possible around the
area today within the CAA pattern, but gusts are only expected to
be significant at KAVL.

Outlook: Dry high pressure persists over the region thru
Saturday. Precip and restrictions may return as soon as Sunday,
as another cold front moves into the region. There may be a brief
lull in these impacts Monday, before low pressure develops along
the front to our west and brings a second shot of moisture overhead
Mon night into Tue.

Confidence Table...

            08-14Z        14-20Z        20-02Z        02-06Z
KCLT       High  88%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$
SYNOPSIS...Wimberley
NEAR TERM...Wimberley
SHORT TERM...PM
LONG TERM...JPT
AVIATION...Wimberley


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