Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
318 AM EDT Tue Apr 23 2019

Valid 12Z Tue Apr 23 2019 - 12Z Fri Apr 26 2019

...Central and Southern Rockies...

Upper trough will skirt across New Mexico during the Day 1 period
before opening up in the southern/central Plains. Favorable
forcing for ascent, per upper jet coupling associated with a vort
max rounding the base of the aforementioned upper trough and
northern stream energy, provides a favored location for
precipitation across portions of New Mexico and southern Colorado.

The highest elevations will see accumulating snow with some
significant totals in the Sangre de Cristos of CO into New Mexico.
 WPC probabilities for 4 inches are moderate and for 8 inches are
low during the Day 1 period above 10,000 ft.  Snow coverage and
amounts drop sharply on day 2 as the upper trough moves east of
the mountains across the southern Plains.

Northern Maine...

The models continue to show a mid level circulation crossing
northern Maine, with a strip of snow north of the low center
focused mainly north of Maine.  As the low level system
approaches, near sfc tempers appear too warm for snow.  A brief
change over is possible as the 850 mb low passes, with cold
advection allowing the change over before the circulation pulls
away and the large scale ascent tapers Thu morning. 

The probability of 4 or more inches pf snow is less than 10
percent day 3.

The probability of significant freezing rain is less than 10
percent days 1-3.

Petersen