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fxus62 kgsp 130855 

Area forecast discussion
National Weather Service Greenville-Spartanburg SC
355 am EST Wed Nov 13 2019

dry and very cold high pressure will remain over the region through
today. A low pressure system developing along the Gulf Coast will
increase rain chances for the end of the work week through the
weekend, especially for the eastern half of the forecast area.


Near term /through tonight/...
as of 235 am: as model profiles indicated, low level moisture and
associated low clouds and flurries continue to diminish near the
Tennessee border. Temperatures in the 10s and locally lower in the
mountains and into the 20s elsewhere with lingering breezy
conditions makes it feel like the single digits to low teens in the
mountains and mid 10s to 20s elsewhere. The extreme cold for this
time of year combined with left over icy conditions across the
mountains (especially above 3000 feet) warrants a continuation of
the current Winter Weather Advisory through early this morning when
an Special Weather Statement for icy roads may be needed for the high elevations. Despite
the unseasonably cold air mass in place, record lows seem unlikely
(see climate section below) this morning unless winds become calm
and allow for a faster drop off in temperatures.

A 1030+ mb high pressure will settle to our east by this afternoon
supporting light east to northeast winds and maintain the
unseasonably cold airmass in place. Highs will likely come in 20-25
degrees below normal with highs only in the mid 30s to low 40s
mountains to 40 to 45 east of the mountains. Charlotte and
Greenville forecast highs of 42 are only 2 degrees off the mark (40)
of the daily record low maximum.

Tonight's temperatures are a bit tricky as high clouds may make a
push into the area late, limiting radiational cooling somewhat.
Return flow off of the Atlantic may also support low clouds
approaching from the southeast late. The current forecast warms
temperatures a couple of degrees over this mornings lows. However,
the potential exists for another night of similarly cold
temperatures should light winds and clear skies prevail, which would
be near record lows once again.


Short term /Thursday through Friday night/...
as of 325 am wednesday: an unseasonably cold air mass will remain
ensconced across much of the southeast and mid-Atlantic through the
period. Meanwhile, the next round of height falls diving southeast
from The Rockies and Great Plains is forecast to carve out an upper
low over the southeast by Friday morning, and this will be
responsible for initiating cyclogenesis along the coastal baroclinic
zone during that time. Short term model guidance is finally
converging toward a consensus regarding the evolution of the
attendant precip shield, with our confidence increasing that at
least the southeast third-ish of the forecast area will receive some
rainfall, with chances gradually increasing from late Thursday,
peaking late Thu night (at 20% across the Tennessee border, ranging to 60%
south of I-85) and steadily decreasing through Friday before winding
down early Saturday. For areas where precip is able to develop,
partial thickness progs support a chilly rain, although cannot rule
out a brief period of -fzra developing across the northern Blue
Ridge Fri morning if (a big if) precip is able to develop that far

Otherwise, precip and/or cloud cover will slow temperature
modification on Thu, except perhaps over the mtns closer to the Tennessee
border, where more in the way of sunshine is possible within a warm
advection regime in advance of approaching height falls. Even there,
maxes tomorrow are forecast to be a solid 10 degrees or so below
normal, while remaining around 20 degrees below climo across much of
the Piedmont. More of a warm-up is likely on Friday, especially in
areas where precip fails to form, but forecast maxes nevertheless
range from about 15 degrees below normal across the Piedmont, to 10
degrees below across the remainder of the area.


Long term /Saturday through Tuesday/...
as of 340 am wednesday: the wave train is forecast to persist across
the southeast during the medium range, with a rather deep but
progressive upper trough expected to traverse the area early in the
new week. At this point, global model guidance is in fairly good
agreement in keeping impacts associated with associated coastal
cyclones south and east of the forecast area. However, due to the
nature of the pattern, forecast confidence is somewhat low, as
models tend to struggle with the details of coastal cyclogenesis
more than a couple of days out. Therefore, after some weekend
drying, slight chance pops return to the forecast Monday through
early Tuesday. Temps will continue to slowly moderate through the
period...from around 10 degrees below normal over the weekend, to
just shy of climatology by day 7.


Aviation /09z Wednesday through Sunday/...
at kclt and elsewhere: VFR conds and light winds will prevail
thru the taf period as high pressure settles into the region.
Asheville gusts are expected to drop rapidly over the next few
hours. Otherwise a few low end gusts are possible just about
anywhere after sunrise through 18z. Return flow behind the high may
support few/sct MVFR and high cigs near the end of the taf period.

Outlook: a low pressure system may bring rain and associated
restrictions to the area later Thursday into Friday. VFR expected
to return sometime this weekend.

Confidence table...

09-15z 15-21z 21-03z 03-06z
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 and ensemble forecasts
are available at the following link:



records for 11-13

Maximum temperature min temperature
station high low high low
------- ---------- ---------- ---------- ----------
kavl 75 1964 32 1906 58 1929 13 1911
kclt 81 1931 40 1920 63 1879 21 2013
kgsp 81 1909 40 1920 61 1929 20 1906

Records for 11-14

Maximum temperature min temperature
station high low high low
------- ---------- ---------- ---------- ----------
kavl 76 1999 32 1906 60 1929 16 1986
kclt 80 1879 37 1976 63 1961 21 2013
kgsp 79 2007 36 1976 62 1929 20 1906


Gsp watches/warnings/advisories...
NC...Winter Weather Advisory until 7 am EST this morning for ncz033-



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