Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 240206

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1006 PM EDT Sun Oct 23 2016

High pressure will remain across the area today before a dry cold
front crosses through on Monday. Strong high pressure will quickly
build back in from the north through the middle of the week...with
another frontal passage expected late Thursday.


As of 1000 PM...A quiet night on tap for the the forecast area as
dry high pressure lingers across the Deep South. Clear conditions
with light winds expected overnight. Low temperatures across the
mtns will reflect an inverse lapse rate, ranging from around 40
within the valleys to the mid 40s across the ridges.

A dry backdoor cold front is expected to slip southward across the
NC foothills and Piedmont during the late morning to mid day period,
passing across the upstate of SC during the early afternoon. Sfc
winds will veer has the front approaches during the morning hours,
becoming NW by mid day Monday. Only a few Cirrus clouds will be
possible with the passage of the front. The timing of weak CAA in
the wake of the front will favor mild high temperatures across the
region. High temperatures are forecast to range from the low 80s
across the upstate to the low 70s within the mtn valleys. RH values
may rise only 5 percentages over values observed on Sunday.


As of 215 PM Sunday, much of the short term will be characterized by
a non or slowly-progressive pattern, with a long wave trough along,
or just off the East Coast, and mean ridging across the central
Conus. This will result in an expansive surface ridge associated
with Canadian high pressure gradually build into the area through
the period. Resultant (relatively) low thickness values/easterly
component to the low level flow will result temps near to a little
below climo through the period. Other than some occl cirrus (esp
toward the end of the period, as a short wave trough ejects from the
central Plains), skies should remain cloud-free.


As of 215 pm EDT Sunday: Overall the extended is pretty quiet, but
we`ll start the period with a shortwave pushing a front down the
Mississippi Valley, approaching the Southern Appalachians Thursday
morning. Of the operational models, the GFS is faster but all
generally bring the front through sometime late Thursday. Moisture
is fairly anemic and guidance seems to be pulling back on the
southern edge of the moisture. The GFS has a little more
precipitation ahead of the front, the ECMWF lingers it a little
longer, but in the end we`re talking slight to low chance pops and
storm-total generally less than 1/2".

Expect a cloudy and cool day Thursday, and with winds swinging
around to the northwest and the downsloping component, should
actually see temperatures warmer Friday into the weekend despite
being behind the cold front. Mass fields diverge between the
operational models but looks like some sort of shortwave will pass
through during the weekend, and have kept the slight chance pops
that we had already advertised across the northern mountains
Saturday night. Not enough model consistency late in the period to
hang our hats on anything specific so just kept with a blend with
slightly above-normal temperatures and continued dry.


At KCLT and elsewhere: VFR conditions expected thru TAF period. A
dry cold front will slide southward across the western Carolinas
during the late morning to midday hours on Monday, passing to the
south by early evening. With little moisture to work with, only a
wind shift is expected with the fropa. Winds will shift from SW to W
or WNW by midday, then veer further to NW Monday evening. Only a few
wisps of cirrus will stream by from the west periodically through
the period. A few stratocumulus may bank up against the western
slopes of the Appalachians Monday afternoon, but shouldn`t impact
any of the TAF sites.

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.

Confidence Table...

            02-08Z        08-14Z        14-20Z        20-00Z
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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