GSP AFD
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
As of 300 am EST Thursday: The forecast will not change a great deal
this morning, with all models on track for a major winter storm.
The operational models are in relatively good agreement with the 500
mb low center track atop our area late weekend. The GFS remains a
few hours faster than the ECM/CMC solutions, but they all lift the
system across the western Carolinas and northeast Georgia late
Sunday and Sunday night. The ECM/CMC mean sea level pressure
prognostics have a slightly farther south/southeast track of the
associated surface low center, mainly across the coastal plain. This
is favored given the strength of the low-level ridge north of the
forecast area and it will likely contribute to slightly colder
profiles and boundary layer temperatures than indicated on the
operational GFS.
Anticipate that the zero degree
850 mb isotherm may pivot near the NC/SC line to create a very sharp
gradient in snowfall from the NC foothills down into the Upstate,
but this remains highly subject to change.
The current thinking is that most of NE GA, Upstate SC, and the
Charlotte metro area will see some degree of warm nosing to undercut
potential snow totals and generate more sleet, with more freezing
rain especially likely at times along and southeast of I-85. 850 to
700 mb frontogenesis will likely sharpen up along and east of the
mountains to enhance precipitation rates Sunday morning. The phasing
process of this southern system back into the northern stream may
accelerate the low passage. That could be a slight limiting factor,
but it may not matter much given the otherwise excellent potential
for significant wintry accumulations across the region as it stands.
Conditions may well be treacherous across the region by daybreak
Monday with snow and ice on the ground and temperatures in the 20s
throughout.