Disturbed weather in part due to a moderately-strong low aloft and onshore flow caused 1/2 to 1 foot of snowfall in the Cascades; around an inch of rain fell at lower elevations closer to the coast. Around 1/2 foot of snowfall occurred in the northern Rockies. Mainly due to the onshore flow, snowpack conditions are warming with some snowmelt. These meteorological conditions are expected to continue on and off through the rest of the week, and another 1 to 3 feet of snowfall are likely in the higher elevations of the Cascades and northern Rockies.
A surface low moved northeastward from the northeastern U.S. Energy aloft and residual moisture caused 4 to 8 inches of snow in Maine, New Hampshire, Vermont, and eastern New York. One-half to 1 inch of rainfall occurred across northern Pennsylvania through northern Indiana. This helped the snowpack in that band become very warm and moderately melt.
An Arctic air mass has moved southward into the north-central coterminous U.S. by this morning. The air mass will spread into the Midwest and East on Wednesday. This will cause the snowmelt in the Midwest to cease (for now).
Heavy rainfall is possible on the Midwestern and Great Lakes snowpack this weekend, but it is too soon to say with any certainty where and what kind of precipitation will fall. The potential exists for heavy rainfall in these areas, but it greatly depends on how the storm, currently over the Pacific Ocean, moves and changes as it moves onshore late this week.
weather.gov
