Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
321 PM EST Fri Nov 11 2022

Valid 00Z Sat Nov 12 2022 - 00Z Tue Nov 15 2022

...Great Lakes...
Days 1-2...

Much colder air channeling southward across the Great Lakes in the
wake of a cold frontal passage will set the stage for locally
heavy snowfall over the next couple of days for the favored lake
effect areas. 850 mb temperatures between -10C and -15C over the
relatively warmer lakes will bring delta-Ts as high as 15-20
degrees and combined with a surface trough pivoting through, this
will bring the necessary lift for lake effect bands. The greatest
snowfall probabilities for the Day 1 period (ending 00Z Sun) are
off Lake Superior where localized 6-10" totals are possible,
supported by the latest WPC probabilities reaching 60-70 percent
for at least 4 inches. Isolated 4"+ totals are possible along
western L.P. Michigan shore during the Day 2 period as the wind
and flow direction becomes a bit less favorable.


...Southern Plains...
Day 3...
A southern stream shortwave trough coming out of the Four Corners
region interacting with colder air in place over the Southern
Plains will have enough cold air, lift, and moisture to support
potentially heavy snow across portions of the Texas Panhandle into
portions of Oklahoma Monday. While uncertainty is still fairly
high with the strength of the system, how much cold air will
remain in place, and how much moisture is lifted northward, the
ensemble and probabilistic guidance is trending higher and shows
potential for accumulating snowfall late in the Day 3 period. WPC
probabilities have increased to near 40 percent for 2"+ with an
isolated signal already for localized 3-4" totals.


The probability of significant icing is less than 10 percent.

Taylor