Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
345 PM EDT Sat Oct 19 2019

Valid 00Z Sun Oct 20 2019 - 00Z Wed Oct 23 2019


Days 1-3...

...Pacific Northwest to the Northern High Plains...
An amplifying trough will continue to move east across the
northern Rockies into the High Plains Saturday night.  Mid level
energy diving into the base of the trough will produce snow
showers, with locally heavy accumulations possible from the higher
elevations of the northern Cascades to the northern and central
Rockies.  As the trough moves into the northern High Plains,
models show a closed upper low and rapidly deepening surface low
developing over eastern Wyoming and western South Dakota Sunday
morning.  This will produce gusty winds and mountain snows from
eastern Wyoming to the Black Hills.  As the low moves farther
east, warm air will support mostly to all rain across the
remainder of the northern Plains and upper Midwest.

While mid level energy embedded within northwest flow will
continue to support periods of organized precipitation across the
Pacific Northwest into the Rockies, snow levels will remain high,
hampering the threat for widespread heavy snow accumulations
Monday and Tuesday.  

The probability of significant icing is less than 10 percent.

Pereira