Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
419 AM EDT Mon Apr 15 2019

Valid 12Z Mon Apr 15 2019 - 12Z Thu Apr 18 2019


...Western U.S....

As mountain snows continue to fall along a slow-moving baroclinic
zone extending from western Wyoming back into central Nevada on
Monday, an amplifying shortwave trough is expected to bring snows
back into the southern Cascades and northern Sierra as it moves
onshore late Monday into early Tuesday.  Heaviest accumulations
are expected to fall along the Sierra, where WPC probabilities
indicate the potential for localized amounts of 8-inches or more
above 8000 ft.

Models show the upper trough continuing to amplify as it shifts
farther east, resulting in some anomalously low heights across the
Southwest late Tuesday into early Wednesday. In addition to some
scattered snows over the higher elevations of central and northern
Arizona, additional snows are likely along the Rockies from
western Montana to Utah and western Colorado.  Overall,
accumulations are expected to remain generally light, with WPC
probabilities indicating little threat for widespread amounts of
8-inches or more on Day 2.

The upper trough is forecast to move progressively into the
Plains, with snows across the West diminishing from west to east
as strong upper ridge begins to build across the West late
Wednesday into Thursday.

Pereira