NWS thoughts…
Monday-Wednesday...This portion of the forecast will be garner the
most attention in the coming days as models have been rather
consistent in bringing a prolonged appreciable snowfall to the Upper
Midwest. A system still churning in the eastern Pacific will drop
southeast along the Rockies Saturday through Sunday. Additional
cyclogenesis will take place over WY/CO/KS Sunday night into Monday
while enhanced isentropic lift broadly spreads east across the
Northern Plains through the Great Lakes. This is likely to have
snowfall develop Sunday night into Monday across MN and WI while the
system slowly develops and lumbers east into the mid-Mississippi
River Valley. This system looks to have two appreciable moisture
sources: Pacific moisture being dragged along and in advance of the
system and tapping Gulf of Mexico moisture northward towards the
Upper Midwest. Given the strong dynamics of the system, its broad
swath of moisture, and its slow forward speed within a pivoting H5
trough to enhance lift, there`s many ingredients in place to
indicate that a prolonged event (early Monday through Tuesday
evening) of accumulating snow is rather likely. There`s still plenty
of model solutions out there with varying snowfall accumulations and
also where those accumulations will be placed, in addition to that
there will be breezy conditions with this system which will
exacerbate winter weather impacts. Therefore, it is too early to
speculate with high confidence snowfall amounts and impacts. These
elements should become clearer over the coming days to give more
details into the forecast.