247pm afternoon AFD from LWX re the thing tomorrow
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Have upgraded the remaining Winter Storm Watch to Winter Storm
Warnings and Winter Weather Advisories. Regardless of headline type,
a band of heavy snow is expected to move from west to east across
the CWA Sunday afternoon. Model soundings are impressive with this
frontogenesis band showing plentiful lift and moisture through the
DGZ. WPC snowband probability tool shows objects from the HREF of
0.05-0.10" per hour. At a 10:1 ratio, this would equate to about an
inch an hour. Given higher ratios in the band as the colder air
rushes in, would not be surprised with reports of 2" an hour in this
band. Thankfully this band will be rather transient and move
eastward quickly as colder Arctic Air rushes in from the NW.
Synoptically, an UL trough will move eastward into the Ohio Valley
tonight. A piece of energy will move ahead of this feature being one
of the parts of this storm. The region will reside in the left
exit/diffluent region of a ~100 kt H5 jet. This is favorable for
upward motion, as indicated by several methods including the long Q-
vectors. Good agreement in FGEN bands forming along the Arctic
boundary as well. These bands will yield the higher rates. Snow will
quickly end Sunday evening as the drier Arctic air moves in.
Upslope snow showers will persist through Sunday night into Monday
morning across the Alleghenies. High ratio fluff is expected,
with the Winter Storm Warning continuing through daybreak.
Given wind gusts of 35-45 mph Sunday night in the mountains,
significant blowing and drifting of snow is likely.