Tuesday, December 8, 2009

The Blizzard of '09

Weather Headlines

Blizzard conditions just south/east of the Twin Cities, where travel is not advised today.

"Plowable" snow tapers by late morning, no more accumulation after 10 or 11 am.

Dangerous wind chills later today through Friday, dipping to -30 at times.

20s may return by the middle of next week, but I don't see a return to freezing between now and Christmas. Yes, it should be a very, bright, white Christmas this year


Red, (very) white and blue. The models all agree: the heaviest snow bands will set up over far southeastern Minnesota and parts of western and central Wisconsin. This may be a little high, but I'm still thinking 4-6" for St. Cloud, 6-8" for the northern/western suburbs of Minneapolis, and 10-14" south/east of St. Paul.



On the nuisance-plowable-crippling snowfall scale (one I borrowed from my favorite Penn State meteorology professor) this will be plowable from St. Cloud to Minneapolis, but potentially crippling just south/east of St. Paul, and for a vast swath of southeastern Minnesota. Blizzard conditions are possible as close as Burnsville, Hastings and Northfield. Head south/east with extreme caution today!

Heaviest snow bands stay just to our east. The GFS weather model is predicting some 12-16" snowfall amounts from Iowa, far southeastern Minnesota and much of Wisconsin. Factor in sustained winds of 30-40 mph, temperatures falling through the teens into single digits, visibilities near zero at times, and you have extremely treacherous travel conditions. Only emergency travel should be attempted today, especially south/east of the Twin Cities. Winds begin to ease by tonight with dramatically better road conditions on Thursday statewide.


Are you enjoying your stay in Minnesota? Or should I say Minne-snowda? Welcome to little taste of the Yukon on the Mississippi, courtesy of one of the biggest December snowstorms in recent memory. We won't see 12" in one day, like we did on December 28, 1982. According to Pete Boulay at the State Climatology Office our last "mega" snowstorm was 16" back on March 8-9, 1999. We won't see nearly that much either, but the combination of snow, wind and cold will make for a very potent 1-2-3 meteorological punch, one that could turn any minor fender-benders into severe cases of frostbite, even hypothermia later today.

* Our heaviest snow so far this year? 6" fell on February 26, 2009.

The heaviest snows will swirl across town this morning, most of the accumulation winding down (from west to east) after 9 or 10 am. By that time many towns will have 6-8" of powder, some suburbs of St. Paul, especially from Stillwater to Hastings and Red Wing, could wake up to considerably more, maybe as much as 10-12". Winds will blow from the north at 25, with frequent gusts to 40 mph, in blizzard territory. The breakfast temperature will pretty much be our "high" for the day, that cruel north wind causing temperatures to tumble through single digits as snow tapers to flurries, and new snow drifts render plows and snow blowers temporarily obsolete.

No, we won't see quite this much snow.

A blizzard is defined as falling/blowing snow with visibilities under 1/4 mile for at least 3 consecutive hours, sustained winds over 35 mph. In the immediate metro area, with homes, businesses, more trees and landscaping, it may not be (technically) a blizzard. But get about 5-10 miles south of 494, cross the river and hit farmland south of Lakeville on your way to Northfield and you may run into blizzard conditions in a hurry. Travel, especially south of the metro area, is highly discouraged, especially through the early afternoon hours. MnDOT may get a better grip on the freeways and state roads by late afternoon or evening, but if you don't have to travel today stay put. Don't tempt fate. Again, it's not so much the amount of snow as it is the other factors, the wind, the cold, the wind chill (dipping to -20, even -30 by late afternoon). In these conditions frostbite on unprotected skin is possible in less than 5 minutes.

Frankly, the weather map (which looked like late September and early October for much of November) is now looking more like late January, when temperatures typically bottom out in Minnesota. Today's snow-blitz will be followed by subzero air - we'll wake up to -5 to -15 F Thursday morning, with a wind chill as cold as -30 to -40 F. Expect to wake up IN A HURRY! Numbing cold lingers through the weekend (although I don't see any more dramatic storms anytime soon). A more westerly component to our winds aloft should push 20-degree air back into Minnesota by next Tuesday or Wednesday (hooray!) Yes, after a stretch like this Minnesotans are actually relieved to see 20s, freezing feels like a gift, a bargain from on high.

Paul's Outlook for the Twin Cities

Today: Winter Storm Warning (Blizzard Warning far southern suburbs). Moderate to heavy snow, tapering to flurries by afternoon. Windy with blowing/drifting and treacherous travel. High: 12 (falling through the single digits). Wind chill: -10 this morning, falling to -30 by evening.

Total accumulation: 6-8" western/northern suburbs of Minneapolis, 7-9" downtowns, as much as 10-12" south/east of St. Paul by midday. Some 10-16" amounts are likely over far southeastern MN and much of western/central Wisconsin.

Tonight: Partial clearing, bitterly cold, winds ease up a bit. Low: -9

Thursday: Bitter sunlight, feels more like late January! High: 10

Friday: Dim sun, still numbing. High: 13

Saturday: Snow showers/flurries, light accumulation possible. High: 16

Sunday: Windy and colder with bright sun. High: 9

Monday: More flurries, a cold breeze. High: 13

Tuesday: Patchy clouds, temperatures still below average. High: 18

Wednesday: A little light snow/flurries. High: 23

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