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

Valid 00Z Tue Apr 16 2019 - 00Z Fri Apr 19 2019


...Western U.S....

Low pressure currently off the OR coast will shift inland tonight
as an onshore flow south of the system continues to bring above
normal moisture into CA and the Great Basin. The parent mid/upper
level trough of the low digs south to the Desert SW tonight
through Tuesday night before ejecting to the southern Great Plains
Wednesday. Snow elevations generally decrease to 4000 to 6000ft
under the trough, resulting in higher elevation in the Sierra
Nevada, Great Basin, and ID/WY/UT on Day 1 (where probabilities
for six inches are moderate) and the CO/NM Rockies and highest
part of the Mogollon Rim in AZ on Day 2 (where probabilities for
six inches are also moderate).

Ridging behind the upper trough builds west from the West Coast
Wednesday with precip diminishing from west to east Wednesday
night.

A low pushes into the AK Panhandle Wednesday night with an
atmospheric river with very high snow elevations (7000 to 8000ft)
pushing into northern WA Wednesday night through Thursday.

Jackson