Well we knew this would happen wwa from gsp
48 49 50
000
FXUS62 KGSP 120903
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
403 AM EST Thu Dec 12 2019
.SYNOPSIS...
A developing coastal storm will bring rain to much of the Southeast
tonight and Saturday. Across portions of western North Carolina,
with temperatures being especially cold tonight, freezing rain
will bring light accumulation of ice to some areas. Precipitation
will continue during the day Friday as as a cold rain and persist
into Saturday, before dry high pressure returns to the area.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 320 AM: Strong high pressure, presently centered between Lake
Ontario and Chesapeake Bay, will dominate our weather today. A dry
northeasterly
flow will continue, maintaining max temps several
degrees below
normal, despite mainly clear skies. The high will
form a quasi-wedge over the region that will persist into tonight.
An upper
trough seemingly comprised of phased northern and southern
stream shortwaves will shift east out of the High Plains early this
morning, with a
sfc low developing over the Midwest.
Cyclogenesis
eventually will occur ahead of the southern wave near the eastern
Gulf Coast tonight, but warm upglide will develop over the cold
high as early as this afternoon. The associated moistening will
quickly reintroduce cloud cover to our
CWFA from south to north,
followed by precip. With parts of the area very near or below
freezing, this will have notable impacts.
PoPs reach
likely range over the GA, western SC and
NC Escarpment
zones around midnight. The cooling of temps will be tricky, with
the increasing cloud cover but also evaporative cooling as precip
gets underway. The fact that the global models generally show less
precip but cooler temps during latter part of the night is a little
concerning. The
NAM is characteristically bullish with precip rates
and the related wet-bulbing, but also is quick to warm temps in
the early morning hours as the "parent high" migrates offshore;
this is important as this is when the guidance consensus on
QPF is
greatest. Looking at vertical profiles from the available models,
even the cooler guidance still features enough of a warm nose
to expect freezing rain where
sfc temps are below 0C; even if
the warm nose is not as strong as
progged, the layer under the
inversion will be shallow and it will be hard to imagine much
refreezing. Altogether, most parts of our WNC zones between the
Blue
Ridge Escarpment and I-85, excluding the Charlotte
metro
heat island, will be at or below freezing for at least some of
tonight`s precip. Accumulation looks unlikely to exceed a tenth
of an inch in most areas, and unlikely to exceed a quarter inch
throughout. We will hoist a
Winter Weather Advisory for 02z to
17z Friday mainly for impacted road conditions in the early morning.
Though precip most
likely will continue into Friday afternoon, temps
will warm enough for ice accumulation to end in the morning. It
will remain a cold and "wedgy" day with breezy northeast winds. Max
temps will be near
normal in the far west, but as much as 15 below
normal in the wetter east.