Created: 12/16/2008 7:10 PM KSTP.com | 
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By: Dave Dahl
It's time for snow lovers of all ages to rejoice because this is going to be one of those winters that has been sorely missed by that group for years!
The jet stream has gone through a major change over the last 10 days, which if it holds will mean a very snowy couple of months for most of the Upper Midwest, and that of course includes Minnesota and Wisconsin. Instead of dry cold air coming from central Canada, we're getting Canadian Pacific air, which is still cold but definitely more moist. Each storm that tracks out of the western part of Canada intensifies as it moves over the Canadian Rockies, not only carrying moisture with it but also gulping up some Gulf of Mexico humidity as well.
Generally speaking these types of storms produce 3 to 6 inch snowfalls over large areas. If they drop down into Colorado before moving toward Minnesota they can become 6 to 12 inch storms, with freezing rain and sleet preceding the heavy snow. If they move down into Texas and Louisiana before heading northward, they usually become the heaviest snow producers for the Upper Midwest, in many cases exceeding a foot over an extensive area.
Here's where the change in the jet stream comes into play. Every time the flow of air aloft becomes more southwesterly, there's an increasing chance that storms will track farther south before heading north. It looks like several significant storms will move into the Upper Midwest over the next week to 10 days. The track of the storms becomes very critical not only for amounts of snow but also for the possibility of freezing rain and sleet. Some of the greatest amounts of damage from winter storms are actually caused by accumulations of ice during a freezing rain event. Trees and power lines come down along with countless accidents caused by the glare ice.
We're on a pace to get over 20 inches of snow this month, and with just average snow the rest of the winter we should end up with over 60 inches by the time we get to April! I still believe we'll have more than average snow in January, which should push our season total over 70 inches here in eastern Minnesota and western Wisconsin with over 80 inches still expected in northeastern parts of our state.
Have a great day!
Meteorologist Dave Dahl
