Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
353 AM EDT Tue Apr 16 2019

Valid 12Z Tue Apr 16 2019 - 12Z Fri Apr 19 2019


...Western U.S...

An upper trough moving onshore this morning will continue to
amplify as it moves farther east, carving out some anomalously low
heights over the Southwest by Wednesday morning.  This may result
in some accumulating snows across the higher elevations of central
and northern Arizona.  Meanwhile farther to the north, a low to
mid level wave associated with the northern stream portion of the
trough will move from Idaho into Wyoming on Tuesday, with a
trailing cold front extending back into the Great Basin.  This may
support some locally heavy high elevation snows from southwestern
Montana down into Utah during the Day 1 period (ending 12Z
Wednesday). 

By early Wednesday, with both the northern and southern stream
components of the upper trough moving progressively to the east,
the greater potential for singificant snow accumulations will move
into the Front Range and Sangre de Cristo Mountains of Colorado
and New Mexico.  With the models showing an upper low closing off
for period as the trough moves across New Mexico on Wednesday,
strong upper forcing to the north along with upslope flow may
generate some locally heavy amounts, especially along the Sangre
de Cristo de Cristo Range, where WPC probabilties show the
potential for amounts of a foot or more during the Day 2 period
(ending 12Z Thursday).

Pereira