Weather Conditions for
Mountain Snowstorms
qSnowstorms in the
mountain of western North America
develop during the passage of
large-scale weather systems, such
as extratropical cyclones,
fronts, and upper-level
troughs, over the mountain
ranges.
qMany of these weather
systems have their origins over
the central and western
Pacific Ocean.
qThe moisture streams in
the atmosphere are concentrated along the frontal systems associated with extratropical cyclones.
qThese moisture streams
are termed “atmospheric rivers”.