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000
FXUS62 KGSP 260630
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
130 AM EST Sun Jan 26 2020

.SYNOPSIS...
Seasonably cool and dry conditions are expected today.  A couple
weak surface lows will bring precipitation to the area Monday and
again during the middle of the week. There is the potential for
a fairly strong and moist weather system to affect the region by
next weekend.

&&

.NEAR TERM /THROUGH TODAY/...
As of 115 AM: Expect shallow moisture in the west to northwest
flow at low-levels to continue to impinge on the NC mountains
overnight, producing cloudiness along the spine of the mountain
chain. Isolated snow showers remain possible along the immediate
border areas overnight, and also above 4000 feet, but little to
no accumulation is expected in these spots.

Otherwise, an upper low will continue to move northeast into
New England while gradually weakening. Any lingering cold air
advection will shut off today. This combined with weak downslope
flow and insolation through thin, but increasing, cirrus will allow
temperatures to rise to just above normal with highs mainly in the
low to mid 50s. Mid to high clouds will begin to thicken across
the forecast area late today ahead of the system approaching from
the west.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
As of 140 PM Saturday...the southern stream looks like it will
remain relatively active through the first half of the week. A
relatively weak system approaching the area Sunday night and moving
overhead on Monday has our immediate attention. At first blush, it
doesn`t appear to have much going for it. A lead short wave dampens
out as it arrives Sunday night, followed by a mostly channeled
vort on Monday and Monday night. Moisture is fairly deep ahead
of the lead wave so there should be enough forcing and moisture
to bring precip in from the west, but not until after mid-evening
Sunday. The dampening wave will have trouble supporting precip east
of the mtns early Monday, so precip chances barely make it to the
chance range. It will take until the trailing wave arrives and we
generate some weak instability over the Piedmont for us to get
scattered precip east of the mtns Monday afternoon. Meanwhile,
the combination of mid/upper forcing and developing W/NW flow
will likely support shower activity on the west side of the
mtns. The boundary layer will remain too warm for the precip
to fall as anything other than rain in the valleys or east of
the Blue Ridge. Not so above 4-5k ft. Fcst soundings suggest a
snow level right around 4k feet through the event Sunday night
and Monday, so all the precip would fall as snow at the highest
elevations, with a few inches possible. Snow levels should fall
in the wake of the system with some NW Flow snow continuing into
early Tuesday morning. At this time, it doesn`t look like anything
more than a potential high elevation advisory, so a Watch is not
contemplated. Our eventual course of action might be dictated by the
eventual snow level...if it falls, then the chances for an Advisory
go up. Tuesday looks quiet and seasonal as high pressure builds in
and NW flow weakens. Temps will be close to normal thru the period.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 220 PM Saturday: The models continue to be somewhat
lackluster in their depiction of a dampening short wave coming
out of the srn Plains on Tuesday night and Wednesday, followed by
a weak nrn stream wave passing to our north Wednesday night. So,
our forecast remains somewhat non-committal with a blanket slight
chance spreading across the region, which would be mostly liquid,
and very little at that. High elevations would have a small chance
at seeing some light snow. It doesn`t look like it will be anything
more than a brief curiosity. Upper ridging Thursday and Thursday
night should support dry high pressure moving past to the north,
thus a quiet period with temps near normal.

Confidence plummets from Thursday night onward. Model guidance has
shown poor run-to-run consistency and relatively weak agreement
between the various model solutions. For the time being, anyway,
the 12Z runs show a consensus toward a Miller type-A low organizing
over the nrn Gulf on Friday, with the low passing to our S/SE
during the weekend. The GFS is about 24 hours faster than the
ECMWF. However, neither has easy access to cold air. The pattern
remains unblocked and the nrn stream progressive, so it does not
appear to be a situation where high pressure would remain in a
favorable spot for cold air supply. So, unless we can conjure up
some cold air from somewhere, this system will look tantalizing,
but may ultimately fail to deliver wintry precip outside the high
elevations of the NC mtns. Best to manage expectations until we
see better run-to-run consistency, but for now we will carry a
chance of precip into Friday and Saturday...mostly rain with some
high elevation snow...and near normal temps.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
VFR east of the mountains. A passing jet streak aloft will maintain
SCT-BKN cirrus across much of the area early this morning, but
mostly clear skies will be seen from daybreak onward. Moist
northwest flow into the Appalachians continues, which will
maintain low VFR to MVFR cigs along the Tennessee border. Early
this morning these may briefly advect over KAVL. Ahead of an upper
level disturbance, increasing clouds and lowering cigs will occur
across the area, but cigs should remain VFR until after the end
of the period at all sites.

Outlook: Passing, weak disturbances may bring brief precipitation
and restrictions on Monday and Wednesday, with VFR prevailing
otherwise during the work week.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
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 are available at
the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$
SYNOPSIS...08
NEAR TERM...HG/65/08
SHORT TERM...PM
LONG TERM...PM
AVIATION...08