Forecast: Major winter storm

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Twin Cities NWS Weather Story highlights heavy snow potential next 48 hours.

Here we go.

A major winter storm is taking aim at the Midwest this week. A powerful low pressure system will wind up in the Oklahoma Panhandle today, then track northeast toward Chicago by Wednesday. A large area of snow will bust out Tuesday from Kansas and Iowa all the way into Wisconsin by late Tuesday.

This system is large and has plenty of moisture and cold air to work with. High winds and blowing snow could bring blizzard conditions to southern Minnesota Tuesday night and Wednesday. Bitter cold and sub-zero wind chills will surge south behind the storm.

How much snow?

If the surface low tracks as far southeast as Chicago, that will mean the heaviest snow bands should favor areas from eastern Iowa into southern Wisconsin. A band of 6″ to 12″+ could fall in Des Moines, La Crosse, Madison and Green Bay.

Southeast Minnesota looks like the best bet to get more than 6″ in Minnesota. Albert Lea, Rochester and Winona could see some 6″ to 10″ totals if the system stays on track. High winds will cause blowing snow, with near blizzard conditions possible Tuesday night and Wednesday along the I-90 corridor.

The Twin Cities will be on the northern edge of this storm. We may see snow begin Tuesday afternoon, and it could increase in intensity Tuesday night into Wednesday. We may end up with a big range of snowfall totals in the metro. The heaviest snow should fall in the southeast metro, with lesser amounts in the northwest.

This is a changeable forecast scenario, but here are some initial thoughts on snow totals for the metro. My early look for the metro is for snow totals somewhere between 3″ and 6″, with the best chance for 6″ in the southeast metro. If the storm tracks any further south, we could see less snow. If it comes further north, we may see more.

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Twin Cities snow meteogram cranking out potentially heavy snow for the metro.

High winds, bitter cold:

Regardless of how much snow we end up with, the main threats form this storm will be high winds gusting to over 40mph Tuesday night and Wednesday, and very cold air. Wind chills will dive below zero by Wednesday, and blowing snow will reduce visibilities on icy roads. Anyone planning travel, especially to the south or east, should be ready for a major winter blast with poor driving conditions.

Watch for updates as the storm develops. This is a changeable and potentially dangerous situation for the Upper Midwest.

Stay tuned!

PH

  • Tanya

    I’ve got my fingers crossed we get some snow but I’ve been this happy before only to see us get a dusting.. I’m used to us missing the first few storms each year. :)

  • Paul Huttner

    Hi Tanya:

    I am a little “concerned” about the possibility that the surface low is tracking too far southeast to bring heavy snow to the metro.

    But the negative tilt of the upper system may be able to throw enough moisture over our cold air dome and give us a plowable shot of snow. This morning’s NAM model run is cranking out .54″ liquid for the metro. That would translate into 6″+ at a 15:1 snow to water ratio.

    Stay tuned for tonight’s model runs!

    PH

  • Colin

    So the cold air acts as a shield to the moisture that is being drawn up north from the low pressure system? But what is a negative tilt in a system? Or am i getting too bogged down on the details?

  • bsimon

    So, if a guy were planning a drive to Chicago & beyond, leaving Wed AM looks like a poor plan…

  • Scott

    Colin,

    From my understanding the tilt of a weather system is the angle in which the axis of the system makes with the lines of longitude. If the tilt is negative, the system is still developing. The opposite is true if the tilt is positive.

    SS

  • Paul Huttner

    So the cold air acts as a shield to the moisture that is being drawn up north from the low pressure system? But what is a negative tilt in a system? Or am i getting too bogged down on the details?

    Posted by Colin | December 7, 2009 12:52 PM

    So, if a guy were planning a drive to Chicago & beyond, leaving Wed AM looks like a poor plan…

    //Not the best idea…I don’t think you’ll get past Eau Claire.//PH

    Posted by bsimon | December 7, 2009 1:27 PM

    Colin,

    From my understanding the tilt of a weather system is the angle in which the axis of the system makes with the lines of longitude. If the tilt is negative, the system is still developing. The opposite is true if the tilt is positive.

    SS

    Posted by Scott | December 7, 2009 4:44 PM

    //Good answer Scott. A neagtively tiltled system tends to throw more moisture farther back to the northwest. That may favor heavier snow for the metro with this system than we might get with a neutral system. It still looks like the heaviest snow band will be southeast of the metro. PH//