FXUS62 KGSP 141956
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
256 PM EST Fri Dec 14 2018
Low pressure will move across the region later tonight and tomorrow
bringing widespread precipitation to the area. Broad high pressure
is then expected to spread over the region and provide warmer and
drier conditions for early next week.
.NEAR TERM /THROUGH SATURDAY/...
As of 250 PM EST Friday: A Flood Watch remains in effect for
portions of western NC through Saturday evening.
With plenty of cloud cover in place and isolated to scattered
showers (heavy at times) today pushing from SW to NE across the
area, it's been quite the dreary Friday, as the insitu wedge in
place across most of the FA has allowed for temperatures to only
climb into the 40s this afternoon. With the combination of a low
pressure system slightly less organized than previously expected
(currently located over LA/MS/AR) and the infiltration of some drier
air, rainfall amounts have not been as high as previously
anticipated. Though the area is in somewhat of a precip lull attm,
with latest radar imagery depicting the western Carolinas and
northeast GA surrounding by rainfall to the west, south and east, do
anticipate an uptick in precipitation across the area tonight
(supported by latest CAM guidance), as sfc low pressure gradually
pushes northeastward. Attm, with anticipation of additional
precipitation and snow melt, the Flood Watch remains in effect through
Saturday evening. Given a non-diurnal temperature trend today,
expect temperatures overnight to remain relatively the same from
On Saturday, sfc low pressure will continue to push northeastward,
though stay just to the west of the TN/NC border, through Saturday
afternoon, as it's associated warm front/cold front near the area.
Scattered showers will continue through the morning hours, gradually
tapering off into the late afternoon/early evening from SW to NE.
With the insitu wedge retreating, do expect high temperatures to be
slightly warmer on Saturday than today, into the low to mid 50s,
into the upper 50s to the SE and into the upper 40s across the
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 110 PM EST Friday: A good amt of h92-h85 moisture will be
associated with an occluded sfc low as it traverses toward the OH
Valley Sun. With good mech/dyno lift...the NC zones will likely see
low-end -shra overnight with some -snsh across the highest peaks. No
sigfnt snow accum is expected into Sun night before the main system
pushes further north and dry air works in from the southwest.
Rainfall totals thru the day Sun will also be low with less than a
quarter inch anticipated and mainly across the nrn NC mtns. Winds
will align nw/ly to w/ly thru the period as the p/grad aligns
parallel to the mtn chain. This will produce a relative warming
downslope component...and along with increasing insol...max temps
will rebound to arnd normal levels Sun. On Mon...llvl thicknesses
support max temps in the m60s over the non/mtns. Wont go that high
yet...but will mention l60s. Either way...Mon will be a rather nice
day after all the clouds and precip recently. Mins will be held
right arnd normal thru the period.
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 220 PM EST Friday: A pretty uneventful couple days to begin
the long term period. A sw/nw elongated upper ridge will slowly
cross the eastern CONUS and support broad high pressure at the sfc.
This stacked high will support a dry column with PWATS generally
remaining below 0.5 inches....or arnd normal for this time of year.
Winds within the mixed layer will be weak...which will lead to a
couple nice seasonal days outside of increasing Ci on Wed.
On Thu...things begin to change. That/s about all that can be said
for now as the models have varying ideas with the structure of an
incoming h5 trof and the degree of available moisture advection.
Climatologically with an upper trof approaching this time of
year...there shud be a defined llvl pressure response and likely
good moist flux out of the GOM/Atl. However...the GFS is an
oddball soln with a cutoff GOM feed and a limited qpf response
mainly across the wrn NC mtns. Other guidance shows better
moisture and precip reaching the FA Thu into Fri. In all cases
tho...the overall pattern would support all rain outside of some
diurnal high mtn -snsh each night. So with the uncertainty
had...will keep slight to low-end chance PoPs during the latter
period. Max temps are still progged to reach arnd normal levels
Thu/Fri as the llvl flow remains w/ly to sw/ly.
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Expect mixture of IFR/LIFR to persist through
the rest of today and through the overnight hours with the continued
infiltration of moisture, low cigs, areas of fog, periods of
isolated to scattered showers and the insitu wedge in place.
Conditions will gradually improve to MVFR throughout the day on
Saturday as low pressure system pushes into the Mid Atlantic and
precipitation tapers off from SW to NE. With insitu wedge in place,
northeasterly winds around 10 kts, with occasional higher gusts,
will prevail at all sites with the exception of KAVL (SE winds 5 to
7 kts). Winds on Saturday will gradually veer to the SE as the wedge
in place retreats.
Outlook: Expect VFR through into the middle of next week as drier
conditions return, with the exception of areas of upslope-driven
cloud cover along the Tennessee border on Sunday.
20-02Z 02-08Z 08-14Z 14-18Z
KCLT High 94% High 80% High 88% High 92%
KGSP High 93% High 90% High 90% Med 74%
KAVL High 93% High 89% Med 78% High 96%
KHKY High 93% High 94% High 92% High 86%
KGMU High 93% High 90% High 90% Med 77%
KAND High 94% High 93% Med 79% High 86%
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:
NC...Flood Watch through Saturday afternoon for NCZ033-035>037-053-