Latest guidance and observed trends are increasingly supportive of a
high potential for heavy snow bands to develop over portions of
central and eastern NC over the next 15 hours, with the focus on the
7p-3a time frame. The latest surface analysis shows frigid high
pressure nosing down through central NC with cold/dry air advection,
including single-digit dewpoints just to our N. Radar continues to
show spotty elevated returns facing this dry subcloud layer and thus
not reaching the ground. However, this is expected to change as the
deep layer forcing for ascent strengthens as we head into the
evening, resulting in saturation of the column and a blossoming of
wintry precip over central NC, all in tandem with a band of
increasing H7-H5 fgen from the central Piedmont E nearly to the
coast between 02z and 08z. Most large scale models depict much
stronger and more focused upper divergence over north-central and
northeast NC than previous runs showed, and the potent mid level
shortwave trough crossing the region this evening/tonight now takes
on a neutral to slightly negative tilt as it reaches central NC.
High res model guidance including recent HRRR runs also show well
the bands of heavier precip starting this evening. Much of the area
will see a fully below-0C column except for the SE, roughly along/SE
of a Maxton-to-Goldsboro line which will see some warming aloft,
although the expected degree of glazing in the SE has trended lower
in recent model runs, and even this area may see decent snowfall
with fairly light icing except for areas SE of Clinton. Given the
higher confidence in the occurrence of heavy snow bands, have bumped
up storm total snow to 2.5-4.5" along and east of a Wadesboro-to-
Roanoke Rapids line. Areas NW of here will likely see some snow, but
lasting a shorter time and with a lower threat of heavy snow, so we
issued an advisory for the remainder of the area, except Forsyth,
for snow totals up to 2". A quick exit of the precip from W to E is
expected by sunrise or very soon thereafter. Lows from the teens to
lower 20s. Chilly NW winds through the night will culminate in
daybreak wind chills into the single digits to lower teens. -GIH