Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 170039
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
839 PM EDT Mon Apr 16 2018

.SYNOPSIS...
After cold conditions tonight, temperatures will warm once again
through midweek. Another cold front will move through the area on
Wednesday night, bringing a chance of rain to the mountains. Dry and
seasonal conditions are expected for the end of the week.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 830 PM Monday: Main update for the 18Z TAF issuance, along
with the expiration of the Wind Advisory, and a Special Weather
Statement issued for snow flurries and/or light snow moving across
the northern mountains into portions of the norther foothills.

As a NW flow snow event continues to unfold along the TN border and
the higher elevations of the NC mountains, latest radar imagery
depicts quite vividly moisture that has broken containment.
Though temperatures are in the mid to upper 30s/around 40
degrees, reports of snow flurries in Burke county have been
reported within the past hour. With radar trends and snow
reports, have issued a Special Weather Statement for areas that
could see snow flurries and/or light snow. As the drying trend
continues, anticipate this activity to taper off within the next
few hours. While am not expecting snow accumulations across the
northern foothills, slick spots may form on roadways. Back
across the higher elevations, snow will continue through tonight
with additional snow amounts of up to an one half of an inch
possible. This with expected winds of 15 to 30 mph and gusts up
to 40 mph across the higher elevations could temporarily reduce
visibility. Motorists should exercise caution on roadways.

Elsewhere across the Upstate and NW Piedmont, other than a few
lingering sprinkles, expect conditions to remain fairly quiet
through tonight with breezy winds. Clouds are expected to gradually
disperse and winds within the boundary layer are expected to
decrease. The coldest night of the week is still on tap for tonight,
with temperatures dropping in the low to mid 30s across the Upstate
and NW Piedmont, down around freezing and below across the
mountains. With favorable conditions in place, a Frost Advisory
remains in affect for portions of the NW Piedmont and Upstate, as
well as a Freeze Warning for the southern mountains.

Otherwise, Frost may not be visible due to dry air limiting
condensation, but surface skin temperatures below 32 will have the
same effect on plants. Tuesday will rapidly warm and frost/freeze
conditions will be short lived. Highs Tuesday will be close to
seasonal normal.

With northwesterly upslope flow along the TN/NC border, some snow
showers will continue until around midnight, after which
continued drying will eliminate any precip chances. 850mb
northwesterly winds of 40 kts will also continue this evening,
as will the wind advisory for some high elevations. Anticyclone
over the Gulf of Mexico will maintain 850mb flow over the area
through Tuesday, and some strong wind gusts at high elevations
in the mountains will continue to be possible Tuesday.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 200 PM EDT Monday: Westerly flow will develop across the
region Tuesday night and Wednesday ahead of a system crossing the
Ohio Valley. This will lead to a rapid warm up to above normal
temperatures on Wednesday. Expect highs to reach around 80 in the
Piedmont and into the middle 70s in the mountain valleys.

A cold front associated with the Ohio Valley system will move across
the region Wednesday night. This will be a dry front for most of the
forecast area. However, a few light showers can be expected in the
mountains near the Tennessee border. Highs will cool to at or just
below normal on Thursday with readings in the lower 70s in the
Piedmont to lower 60s in the mountain valleys.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 230 PM EDT Monday: The medium range period will begin quiet,
with a very interesting flow pattern evolving by early next week. An
upper trough axis will be on its way out of our area in the wake of
a dry front Thursday night and Friday, with benign and slightly
cooler than normal conditions expected through Saturday as surface
high pressure moves through the OH River Valley and slowly migrates
towards the Mid-Atlantic coast by early Sunday. Aloft, a split flow
pattern will take shape as an upper low cuts off over the southern
plains and swings down towards the southeastern states.

As this upper low and its surface reflection drop towards the Gulf
coast Sunday, the sprawling surface high (over parts of New England
and extending off the coast) appears that it will set up a wedge-
like surface pattern down the spine of the Appalachians. Global
models are in surprisingly good agreement on this point, though the
evolution of this type of pattern is generally quite uncertain. The
upper/surface cutoff low will spread precipitation into our area
beginning Sunday night, aided by the potential wedge of surface high
pressure over the Carolinas. The pattern isn`t particularly
progressive, so without getting into finer details, it appears that
the start of next week will be wet, with a reduced diurnal range and
max temperatures well below average.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Expect VFR to prevail through the valid TAF
period, with VFR cigs through tonight becoming FEW250/SKC on
Tuesday. Latest radar imagery depicts light snow spilling over into
portions of the northern foothills. Would not entirely rule out snow
flurries at KAVL/KHKY over the next couple of hours, but do expect
activity to taper off as a drying trend continues. Gusty NW winds
are expected to subside across the Upstate and NW Piedmont tonight,
with sustained winds AOB 15 kts prevailing at KAVL overnight. Will
note gusty NW winds up to near 40 kts are expected across the
northern mountains at elevations about 3500 ft. This along with snow
showers could briefly inhibit visibility - however not affecting any
of the terminals directly. After daybreak on Tuesday, expect NW
Winds to continue with sustained winds 15 to 20 kts and gusts up to
30 kts possible, subsiding after 00Z.

Outlook: Other than perhaps some lingering mountain showers, dry and
cooler conditions will continue into mid week. A dry cold front will
arrive from the west on Thursday, with some scattered restrictions
possible.

Confidence Table...

            00-06Z        06-12Z        12-18Z        18-00Z
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:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Freeze Warning from midnight tonight to 9 AM EDT Tuesday for
     GAZ010.
NC...Frost Advisory from 3 AM to 9 AM EDT Tuesday for NCZ035>037-
     056-057-068>072-082-502-504-506>510.
     Freeze Warning until 9 AM EDT Tuesday for NCZ051-052-058-059-
     062-063.
     Freeze Warning from midnight tonight to 9 AM EDT Tuesday for
     NCZ048-053-064-065.
SC...Frost Advisory from 3 AM to 9 AM EDT Tuesday for SCZ001>003-
     006>009.

&&

$$
SYNOPSIS...SW
NEAR TERM...SGL/WJM
SHORT TERM...SW
LONG TERM...Carroll
AVIATION...SGL



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