Friday, January 22, 2010

Storm Update - Weekend Slop-Storm

1-10", give or take. I wasn't kidding with massive snowfall range I predicted earlier. Click on the map to take it full-screen and you'll see the (incredible) contrast from the eastern suburbs of St. Paul (maybe a slushy inch?) to Brainerd, where 10" may pile up by Monday. Again (disclaimer time), a slight shift in the storm track, even 50-75 miles, could make the difference between a couple inches and a major snowfall. People in Wadena, Detroit Lakes and Cross Lake can look forward to a significant new pile of white in their yards by Monday, but from Monticello, Elk River and Delano south/east towards the Twin Cities, Mankato and Cannon Falls, the vast bulk of the heaviest precipitation will probably fall as rain.


11 am Friday Update

Just got a look at the latest guidance: still feel fairly comfortable (wrong word) with 3-6" for the greater St. Cloud area, but less for the Twin Cities, possibly 2-4" (4" western 'burbs) with a higher percentage of rain/ice for the southeastern half of Minnesota. A significant percentage of precipitation this weekend will fall as rain (mainly Saturday). The farther north/west you travel across Minnesota, the less rain you'll see, more precipitation falling as snow/sleet/freezing rain. Parts of the Red River Valley and far western MN (near the Dakota line) could still pick up 8-12" of snow by Monday, but between a changeover to rain - and the "dreaded dry tongue", a surge of dry air sweeping in from the Desert Southwest, snow amounts will quickly taper as you approach the Twin Cities - Rochester/Winona may be lucky to pick up 1-2" of slushy snow at the tail-end of this messy storm late Sunday into Monday. Expect mainly wet (major) roads tomorrow with mostly-rain, but a changeover back to snow is still likely Sunday as the atmosphere cools, but the latest guidance is strongly hinting at dry air cutting off the heaviest snow Sunday - the real action shifts farther east into Wisconsin, closer to the actual storm track.

Tracking the dreaded "dry tongue". Check out the surge of dry air wrapping into the storm circulation by noon on Sunday. The heaviest precipitation (mostly rain) is forecast to be over Wisconsin and Illinois - if the NAM model verifies the snow should be very light for much of Sunday, good news if you're trying to get to a Vikes party later in the afternoon. Moisture will wrap around the Great Lakes storm, meaning light snow lingering into much of Monday. I don't expect travel conditions to improve significantly until Tuesday, when temperatures fall into the teens. Yes, it's going to get cold again, but only for 4-5 days. Long-range guidance is hinting at more 20s, even a shot at 30 by the first week of February.

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