Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 270246

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1046 PM EDT Wed Oct 26 2016

A weak and mostly dry cold front will cross the area Thursday. Warm
high pressure returns Friday before another weak frontal passage
occurs late Sunday. Warm and dry high pressure moves in early next


As of 1035 PM: BKN/OVC high clouds continue to stream across the
forecast area in advance of a short wave trough and attendant
frontal boundary along and just east of the Miss Valley. This trend
will persist through the night. It`s always a bit of a challenge to
determine what if any impact cirrus will have on min temps, and
indeed a few of the usual outlying/cool areas are already sitting at
their forecast lows. Nevertheless, it appears most areas should see
mins a little warmer than normal. Mesoscale and short term model
guidance continue to hold any pre-frontal shower activity west of
the Appalachians through the overnight, so pops will be maintained
at less than slight chance.

Otherwise, surface high pressure draped along the eastern seaboard
will continue to migrate offshore tonight as the approaching surface
cold front crosses the lower OH and mid MS river valleys. The upper
wave is expected to gradually dampen as it crosses the region on
Thursday. Upper level forcing will be quite muted with the trough
passage, and the surface front is expected to only slowly lay over
into the region late in the day. The slightly deeper moisture along
the frontal zone will then spread across the mountains through the
day but with just scattered PoPs advertised. Forcing and moisture
appear much less east of the mountains Thursday afternoon and modest
instability will be relied upon to get much QPF at all. The
instability looks quite reserved in most areas, with SBCAPE possibly
reaching 500 to 700 J/kg in the far SW mountains and also southeast
of CLT late day. The thunder potential is slight at best. Maxes
should run about a category above climo with pre-frontal warm
advection Thursday.


As of 2:30 pm EDT Wednesday:  May feature for Thursday night through
Saturday is the passage of a frontal system Thursday night which
will mainly serve to shift the winds from southwesterly to
northwesterly.  There is a slight chance for showers with the
passage of the front, but moisture in the atmosphere looks to still
be on the dry side, and the dynamical lift is not strong enough to
produce significant rainfall. Temperatures will not be much affected
either, with highs Friday and Saturday reaching the low 80s Friday
and Saturday in piedmont areas, though low temperatures will be a
little close to normal (though seasonally warm).

Following passage of the front Friday morning, POPs decline to
single digits through Saturday as broad, flat ridge over the
southeast CONUS replaces the frontal trough and keeps the boundary
layer dry and keeps shortwaves north and west of the area.


At 230 PM Tuesday: Medium range guidance indicates that low pressure
will track NE off the New England coast. An associated cold front is
forecast to slip south across the mid Atlantic. Sfc high pressure,
around 1025 mb, will become centered over the New England states by
Monday morning. At H5, a long wave trough will ripple across the
central and northern Atlantic. The passage of the trough will limit
the strength of the sfc high, reducing the ridging sw along the east
facing slopes of the Appalachians. Precip and cloud cover should
favor the region north of the forecast area. I will keep the
forecast from Sunday to Monday dry. Temperatures are forecast to
remain 10 to 15 degrees above normal.

On Tuesday, the center of a H5 590dm ridge is expected to build
across the deep south. Another dry cold front is forecast to slip
across the mid west. Warm and dry conditions will remain on Tuesday,
possibly a degree warmer than Monday. The mid level ridge will
expand across the southeast U.S. as sfc high ridges across the
western Carolinas. On Wednesday, dry wx with high ranging from the
mid 70s within the mtn valleys to near 80 east of the mtns.


At KCLT and elsewhere: VFR conditions are expected to persist
through at least the first 12 hours of the forecast period, with
only gradually increasing/thickening high clouds expected. Cannot
rule out some fog and/or low stratus development in the mtn valleys,
but with the increasing high clouds, coverage should be patchy at
worst. Low level moisture within increasing SW flow is expected to
result in stratocu overspreading the forecast area from around
sunrise through the morning into early afternoon. This is generally
expected to be in the 035-050 range, but MVFR could be seen at the
Upstate SC terminals. Otherwise, light SE winds overnight will
become SW and increase to 05-10 kts late Thu morning. A weakening
cold front may bring isolated to widely sct showers, esp to the NC
mtns and foothills by the end of the period, but chances are too
remote to advertise in the TAFs attm.

Outlook: Isolated showers will be possible Thu evening. Dry high
pressure will return Friday through the weekend and last into early
next week.

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  97%     High 100%
KAND       High 100%     High 100%     Med   77%     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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