Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
408 PM EDT Fri Mar 29 2019

Valid 00Z Sat Mar 30 2019 - 00Z Tue Apr 02 2019


...Great Lakes and Northeast...

Favorable upper jet forcing and mid level energy lifting along the
leading edge of an amplifying northern stream trough will support
surface wave development along a stalled frontal boundary, with
precipitation spreading north of the boundary.  For many areas
from the Great Lakes into the interior Northeast, models show
precipitation beginning as a period of mixed frozen precipitation
before transitioning to rain and then back to frozen before
precipitation ends.  WPC probabilities indicate a Slight Risk for
snow accumulations of 4-inches or more across northern Lower
Michigan on Day 1 (ending 00Z Sunday).  During the Day 2 period
(ending 00Z Monday), a Moderate Risk for accumulations of 4-inches
or more is indicated from northeastern Ohio into western New York
and the Tug Hill and Adirondack region.  Models are showing a
period of enhanced precipitation across this region during the
overnight period Saturday into Sunday, supported by southern
stream energy and right-entrance region upper jet dynamics.

...Southern Rockies...

Remnant energy associated with a weakening low along the Northwest
coast is forecast to shear southeast through the Great Basin, with
some models showing a closed low briefly closing off as it moves
into the Four Corners region Saturday night.  This may produce a
period of moderate snow along the western Colorado and northern
New Mexico mountains, with WPC Day 2 probabilities indicating a
Slight Risk for accumulations of 8-inches or more along the San
Juan Mountains.

Pereira