Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 151852

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
252 PM EDT Sun Apr 15 2018

In the wake of a vigorous cold front, much cooler air will
overspread the region tonight into Monday, but temperatures will
warm once again through midweek. Another cold front will move
through the area on Thursday, however this front is not expected to
produce much precipitation.


As of 240 PM EDT Sunday: Line of strong/severe convection is moving
out of the foothills and into the piedmont and eastern Upstate at
this time. Will cancel the tornado watch west of the line.
Thunderstorm wind damage and isolated tornadoes will remain possible
with the line as it moves east across the I-77 corridor. Although
flooding chances have diminished behind the line, will keep the
flood watch in place as there`s additional weak convection moving
across the area through early evening. Will adjust PoPs for these
trends eventually trimming PoP back to the mountains overnight as
northwest flow precip kicks in.

CAA behind the front and increasing NW flow will turn the precip to
snow across the higher elevations. Can`t rule out some flakes in the
valleys, but any accums should be above 3500 feet with the best
amounts in the Smokies and locations like Beech Mtn. Even there,
amounts should max out near 2 inches, but slightly higher amounts
are possible. Since accums will be limited to the highest
elevations, will not issue an advisory for now. Temperatures across
the mountains will be quite cold, so have issued a freeze warning
for the locations where the growing season has been turned on and
most of the county will be below freezing. Outside of the mountains
breezy and clearing conditions develop with lows a little below

NW flow snow showers taper off Monday but will linger across the
higher elevations through the day. Windy conditions continue across
the mountains with breezy conditions elsewhere. Skies will generally
be mostly sunny outside of the NW flow areas. However, some of the
mountain wave clouds could break containment and spread east across
the foothills and piedmont. Highs will be around 20 degrees below
normal across the mountains and around 15 degrees below normal


As of 130 PM Sunday: The upper flow atop the SE Conus will continue
deamplify through Tuesday and rising heights will aid in boosting
max temperatures back to near climo levels under abundant sunshine
after a rather chilly early morning. The WSW flow through a deeper
layer should increase on Wednesday, well downstream of the eastward
rippling mid-Conus/Ohio Valley s/wv energy. For the cwfa, under a
mix of sun and clouds, downslope aided warming is expected to boost
piedmont maximums to around 80.


As of 145 PM Sunday: At the start of the period, an eastern Conus
broad trough will be in place as energy rotates through the l/wv,
well north of the region.  This should be able to drag a moisture
starved cold front across the cwfa on Thursday with little to no
shower probabilities.  The upper pattern does remain progressive, so
by the end of the work week, the pattern will be deamplifying once
again, featuring rising heights atop the region. The flow around sfc
hipres centered over the Great Lakes will result in an easterly llvl
flow, hence, maxes should top out near if not below the mid-April
climo.  The medium models look to be in decent agreement for next
weekend featuring building deep layer ridging atop the region on


At KCLT and elsewhere: Line of strong to severe convection will move
east of KHKY by 19Z and KCLT by 21Z. However, there could be some
embedded thunder in the trailing area of showers that won`t
clear the entire forecast area until 00Z or so. Conditions will
generally be MVFR, cig and vsby, but IFR cigs will be possible along
with IFR vsby in the heavier showers. S to SW very gusty winds will
continue this afternoon then turn SW to WSW behind the front this
evening. Wind speeds should taper off but low end gusts will
continue. KAVL will see SSW wind becoming NNW after fropa. Some MVFR
cigs will linger after fropa but vsby should become VFR. Cigs should
lift and scatter out through the night with MVFR then low VFR
lingering longer at KAVL where clouds will move up the valley in the
NNW flow. Gusty W to NW wind continues Monday with clearing skies.
That said, mountain wave clouds will linger through the day and some
may break containment and spread across the foothills and piedmont.

Outlook: Other than perhaps some lingering mountain showers, dry and
cooler conditions continue into mid week. A dry cold front may
arrive late in the week from the northwest.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       Med   78%     High  89%     High 100%     High 100%
KGSP       High  96%     High 100%     High 100%     High 100%
KAVL       High  89%     High  86%     High  98%     High 100%
KHKY       High  96%     High  82%     High 100%     High 100%
KGMU       High  90%     High  94%     High 100%     High 100%
KAND       Med   79%     High  98%     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:


GA...Flash Flood Watch until 8 PM EDT this evening for GAZ010.
NC...Flash Flood Watch until 8 PM EDT this evening for NCZ033-
     Freeze Warning from midnight tonight to 10 AM EDT Monday for
SC...Flash Flood Watch until 8 PM EDT this evening for SCZ001>003-


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