Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 231038

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
638 AM EDT Tue Oct 23 2018

Seasonable temperatures are expected today ahead of an approaching
dry cold front. Cooler conditions will return behind the front with
precipitation chances increasing towards the end of the week. Though
a gradual warming trend expected, temperatures will remain below
normal through the weekend.


As of 735 AM EDT: Cirrus will continue across the area in fairly
zonal flow this morning. South to southwest return flow will bring
some moisture and low clouds across the southern portions of the
Upstate and NE GA. Mountain valley fog and patchy lake/river fog
outside of the mountains will dissipate by mid morning. Surface high
pressure will move off the Carolina coast today with a lee trough
setting up just east of the mountains. Highs will be near to
slightly above normal. A passing upper trough this afternoon will
push a shortwave through our region and push a weak dry surface cold
front across the area during late afternoon or evening. Winds turn N
to NE overnight but lows will actually be warmer than this morning,
near to slightly below normal.


As of 300 AM EDT Tuesday: With an upper trough progged to be pushing
off the New England coast Wednesday morning and upper ridge set up
across the central US, the short term forecast period kicks off
quiet with dry, NW flow in place and sfc high pressure dominating
the weather pattern. The next chance for precipitation returns to
the FA as early as Thursday evening ahead of a developing Gulf
system (this timeframe based on the latest GFS). The ECMWF, however,
has a much slower progression with this system, with the potential
for precip beginning into Thursday night. Model consensus has lacked
the past few days with this system and it`s track, both temporally
and spatially, but for now have kept with the overall trend of
increasing PoPs from SW to NE across the FA beginning as early as
late Thursday afternoon.

High temperatures on Wednesday will be the warmest of the rest of
the week, with mid to upper 60s/around 70 degrees across the area,
with the exception of lower 60s and cooler across the mountains. A
nearly 10 degree drop in high temperatures is expected for Thursday
with increasing cloud cover, as overnight low temperatures both days
will be just below normal.


As of 330 AM EDT Tuesday: As mentioned above, model consensus on the
track and timing of the approaching Gulf system for the end of the
week and into the weekend has lacked. Though will note the GFS
trend continues to have a Miller-A type scenario, suggesting the
developing system will track across northern FL and move into
the Atlantic as it ascends up the Carolina coast into Friday
night. The latest ECMWF continues to suggest a slightly slower
and more northern/inland track. Overall, an unsettled weather
pattern is expected through the weekend and into early next
week, as on the backside of the exiting system, another upper
trough is progged to dig into the Southeast and bring the system
towards the end of the weekend. A "brief" lull in precipitation
is anticipated between the systems, but again, the longevity of
this lull varies based on the different model runs.
Precipitation will gradually taper off late Monday. As for the
type of precipitation, rain is expected across a majority of the
area. However, would not entirely rule out a mix of rain/snow
across the higher elevations at times Thursday night and again
into early Saturday morning with colder temperatures. Little to
no accumulation is expected. For the following system moving in
towards the end of the forecast period, temperatures and
thicknesses do not support additional snow potential attm, but
would not entirely rule out some snow flakes mixed in with rain.

Aside from the isolated to scattered nature of showers,
anticipate cloud cover to linger through the medium range, with
a some breaks in the clouds possible in between systems. With
high temperatures in the upper 40s/lower 50s on Friday, a
gradual warming trend is expected through the weekend into early
next week, though temperatures will still remain just below


At KCLT and elsewhere: VFR expected through the period. Lee
trough develops today, setting up a light WSW wind. Cirrus will
remain across the area through the day before diminishing tonight.
Low VFR lingers near KAND through mid morning but no more cigs are
expected. Winds turn NW then NE overnight as a dry cold front moves
through and high pressure builds in form the north.

Outlook: Patchy fog and/or low clouds will be possible across the
mountain river valleys around daybreak on Wednesday and Thursday.
Otherwise, expect VFR through Thursday. Precipitation and associated
restrictions will likely redevelop Thursday night into Friday or
Saturday as a low pressure system moves east along the Gulf Coast
and transitions to a coastal Atlantic low.

Confidence Table...

            10-16Z        16-22Z        22-04Z        04-06Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       Low   31%     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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