Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 242342

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
742 PM EDT Mon Oct 24 2016

Seasonal and dry high pressure will remain over the region through
Wednesday. A weak cold front will cross the area Thursday. High
pressure briefly returns before another weak frontal passage on


As of 730 PM EDT...A dry cold front can be analyzed as a wind shift
line, which as just crossed the GSP to CLT areas within the last
hour, and continues to push southward. Overall, winds are becoming
lighter and only a few wisps of cirrus continue to stream across the
area from time to time. So the forecast looks on track, with only
minor tweaks to the hourly T/Td grids and to the sky and wind grids
for the 00z TAFs.

As of 200 PM EDT: Upper level divergence on the south side of a
broad mid Atlantic jetlet may produce a few thin mountain cirrus
clouds into tonight. Meanwhile, A back door cold front at the
surface will move southward through western NC by this evening and
then settle south of the forecast area overnight. Only a few
locations in sheltered northern mountain valleys appear cool enough
for any patchy frost formation, so no advisory is expected.

Otherwise, deep layer NW flow will continue, with heights rising and
the pressure gradient relaxing through Tuesday. Surface high
pressure will build over from the north behind the front and push
lower thicknesses into the region. Weak downsloping will
continue to provide some measure of warming east of the mountains
despite the falling thicknesses - with maximum temperatures fairly
close to climatology.


At 2 PM Monday: On Tuesday evening an upper trough will be off the
East Coast, while an upper ridge will be over the Great Plains. The
ridge retrogresses over the Rockies on Wednesday while the eastern
trough progresses offshore, and another trough amplifies over the MS
River Valley. By Thursday the upper trough reaches the Great Lakes,
and the Central and Southern Appalachians, with an associated
shortwave crossing the mountains, while the upper ridge progresses
to the Eastern Slopes of the Rockies.

At the surface, on Tuesday evening a cold front will be well south
of our area, an high pressure will extend from the Great Lakes to
the Carolinas. High pressure persists over our area into Wednesday
night, finally weakening as a cold front approaches from the west
on Thursday. Meager moisture ahead of and along the front will limit
precipitation amounts, while instability will be limited for
convective development. Temperatures will run near normal.


At 2 PM Monday: On Thursday evening an upper trough will be over the
Eastern USA, while an upper ridge will exist along the East Slopes
of the Rockies. The pattern progresses such that by Saturday the
easter trough moves offshore, while the ridge upstream remains along
the Front Range, resulting in deamplification and more zonal flow.
By monday the upper ridge progresses to the MS River Valley, while
the trough downstream moves little, and as a result, the upper
pattern amplifies.

On Thursday evening a cold front will be dropping south across our
area, with only limited moisture along the boundary. High pressure
settles in over our area on Friday and Saturday. Another cold front
reaches our area from the north on Saturday night, moving slowly
south of the area by Monday. Moisture with the second front will be
limited as well, and instability will be lacking. Temperatures will
run slightly above normal.


At KCLT and Elsewhere...A dry cold front continues to push south,
and as of the 00z TAF time, as pushed south of CLT and GSP. Winds
will favor a NW direction this evening, then gradually veer to NE
overnight thru Tuesday morning. Wind speeds will be generally in the
5-9 kt range. By Tuesday afternoon, winds will become lighter and
veer to more ENE or ESE by end of the 00z TAF period. With dry air
mass filtering in behind the front, only high clouds are expected,
mainly periods of thin cirrus.

Outlook: Dry high pressure will persist over the Southeast through
Wednesday. Then a fast-moving cold front will cross the area
Thursday or Thursday night, but with limited moisture. Dry
conditions return for next weekend.

Confidence Table...

            23-05Z        05-11Z        11-17Z        17-18Z
KCLT       High 100%     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:




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