FOUS11 KWBC 140708
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
208 AM EST Tue Jan 14 2025

Valid 12Z Tue Jan 14 2025 - 12Z Fri Jan 17 2025

...Great Lakes...
Days 1-3...

Deep cyclonic flow is in place over the Great Lakes and will start
to erode from NW to SE starting later today. Light to moderate
snow over the western Great Lakes will wane later tonight with an
additional few inches of snow over the favored lake belts. East of
Lakes Erie/Ontario, locally heavy amounts will fall over the
typical snowbelts today then start to lessen in intensity and
transition from single banded to more multi-banded as the upper
trough swings through. Starting tomorrow evening, an approaching
shortwave and surface warm front will bring in some light WAA-
driven snow to the western Great Lakes that will progress through
the eastern Great Lakes.

For the lake effect snow, WPC probabilities of at least an
additional 6 inches of snow D1-1.5 are highest (>70%) over
northwest PA into southwestern NY where 10+" are likely in the
band. East of Lake Ontario, WPC probabilities for at least an
additional 12 inches of snow are highest in the Tug Hill Plateau.
By D3, as the weaker system moves through the area, WPC
probabilities for at least 4 inches of snow are low (10-40%)
downwind of Lakes Erie/Ontario and also over the central
Appalachians thanks to some modest upslope.


...Eastern OH/W PA...
Day 1...

Steep lapse rates amplified by an amplified shortwave moving
through the base of the broader scale trough may support snow
showers and potential squalls east and southeast of Lake Erie this
afternoon. The NAM and GFS continue to show Snow Squall Parameter
values greater than 2 as 850mb temps of -15C or so move across the
region. Accumulations will generally be light, but a brief period
of intense, wind-driven snow may create hazardous driving conditions.


For the Day 1-3 period, the probability of significant icing of at
least 0.10" is less than 10 percent across the CONUS.


Fracasso


$$
--- SBBSecho 3.20-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)