Wednesday, January 20, 2010

Weekend Outlook: 1-12"

Weather Headlines

ICE ALERT !!!

* Nuisance snow event today, mixing with freezing drizzle - significant icing possible, around 1" of slush expected.

* Better travel conditions Friday.

* Main event arrives Saturday, mixing with rain and freezing rain (central/western MN).

* Changeover to snow Sunday, "plowable" snow still possible for central Minnesota, some 8-12"+ amounts possible over the western third of Minnesota by Monday.

* Huge west-east contrast in potential snowfall amounts: couple inches for the Twin Cities, potential for 3-6" St. Cloud, over 10" possible west of Willmar and Wadena.

* Turning colder next week, back into the teens as heavy coats/parkas return.

Hi, I'm Paul. I'll be your weather-server today. Here's a menu - I'll give you a few minutes to look it over. I should warn you you'll probably need a strong stomach to get through this. Take a deep breath. Deeper. The appetizer arrives today, about an inch of slushy snow, washed down with freezing drizzle, capable of a tasteless coating of ice capable of fender-benders and a few painful falls. Buyer beware.

Gray hairs for meteorologists. Hey, I'm happy to have any hair at this point in my life - color is optional, but you can see why we're nervous about the weekend storm. If the storm zigs or zags 75 miles farther west (or east) the ultimate snow amounts will change, possibly dramatically. Either way, the greatest potential for a foot or more of snow will be over far western and southwestern Minnesota.

An end to our weather-honeymoon. Here is predicted snowfall through early next week. The GFS model may be overdoing the amounts a bit (12-16" for far western Minnesota?) But the trends are probably correct, more west, less east - a huge contrast across the state. A forecast of 1-12" would likely get me admitted to the Happy Home for Wayward Weathermen. But in the case of our weekend storm, looking at the entire state, it's probably an "accurate" prediction!

Yesterday this same frontal zone sparked a severe ice event across Iowa (more than 1" of glaze ice in western Iowa, near Storm Lake, Cherokee and Dennison). There is absolutely, positively nothing worse than glare ice. Four-wheel drive, front-wheel drive, nothing short of a Sherman tank will get you around town (safely) when there is severe icing. It's especially insidious: you look out the window and it looks like plain old rain. But step outside (and expect to wind up in a horizontal position - against your will). Again, falls on ice trigger nearly as many emergency room visits every year as traffic accidents, which is hard to fathom. That's what seniors are terrified of (among other things). It's not snow, but ice, and the risk of falling, breaking a hip, winding up in the hospital, contracting an infection.... I'll stop now, but you get the picture. Bottom line: in spite of a (lousy) inch or so of actual snow today the ice component may result in commute times double, even triple average. Leave PLENTY of extra time to get around town today.

Computer forecast for noon Saturday. The center of the storm is predicted to be over northern Iowa, the rain/snow line draped right over central Minnesota - mostly rain for the Twin Cities, a rain/snow mix for St. Cloud, mostly snow for far western Minnesota (where the heaviest snow amounts are expected from our weekend storm, possibly a foot or more by Monday).

We come up for air tomorrow as precipitation tapers to flurries, even a little freezing drizzle, but I expect roads to be a slightly better shape, highs in the upper 20s to near 30, most freeways and major highways (that have been treated by MnDOT) just wet/slushy, as opposed to icy. Take advantage of a brief lull in the storm to stock up on, well, whatever needs stocking up on, because the weather will progressively go downhill over the weekend. This seems likely: travel conditions will get worse as the weekend wears on - a period of rain on Saturday (yes RAIN during the coldest week of winter, on average) will mean mainly wet roads, but some icing is still possible on secondary roads and side streets, especially west of St. Cloud and Hutchinson. As a soggy, southern storm tracks directly over Minnesota Sunday the atmosphere will cool, mixed precipitation changing back over to mostly snow, and it should start to accumulate by the PM hours Sunday. The drive to that Vikes game could be a bit precarious, temperatures dipping below 30, previously wet roads becoming snow-covered, especially after dark (around 5:30 pm or so). The models go back and forth on snow amounts, the latest GFS computer forecast is a bit more aggressive/impressive when it comes to snow amounts, especially across the western third of Minnesota, where a cool foot of snow can't be ruled out by Monday. It looks like a MAJOR contrast in snow from west to east: over a foot west of Willmar and Wadena, 10-15" amounts possible from Windom to Alexandria to Detroit Lakes, maybe 3-6" in St. Cloud, while the Twin Cities will be lucky to see 1-3" of snow late Sunday into Monday morning. The main surge of dry air wrapping into the storm (the dreaded "dry tongue") now looks like it may sweep into Wisconsin, not eastern Minnesota. My confidence level is still low, the weekend forecast still has "high bust potential" (meaning there is a LOT that can go wrong with this forecast), but I feel reasonably confident about a few things:

1). About 1" of slush today, mixed with ice.

2). Period of rain/ice Saturday, which will keep amounts down over central and southeastern MN. Far western Minnesota may see mostly snow Saturday and Sunday, and that's why there's a potential for a cool foot of snow to pile up west of Willmar.

3). Changeover to mostly snow Sunday, from west to east, travel conditions getting worse as the day goes on.

4). Light snow lingering into Monday - travel conditions still very poor as we star the work week.

5). Turning much colder next week, highs stuck in the teens by Tuesday/Wednesday.

Stay tuned - four new computer runs come in every day (joy). Each new run may have a new solution on the ultimate storm track. A jog of 75 miles farther west or east could make the difference between 2" and 10" in this kind of a pattern. If a changeover to rain does NOT happen we could be looking at a very, large pile of snow, especially central Minnesota. That's possible, but still unlikely, the odds less than 30% Then again, when it comes to Minnesota weather, everything that can go wrong WILL go wrong, usually at the worst possible time, for example, during an NFC Championship Football Game featuring our amazing Vikings.

Paul's Outlook for the Twin Cities

Today: Light snow likely, mixing with a little freezing drizzle. Around 1" of accumulation possible. Winds: east 10-15. High: 28

Tonight: Light snow tapers to flurries. Low: 24

Friday: Overcast, a few more flurries - better travel. High: near 30

Saturday: Mostly rain, freezing on contact with some surfaces outside the metro. High: 35

Sunday: Changeover to snow, travel conditions getting worse as the day goes on. High: 32 (falling)

Monday: Light snow, total accumulations from the storm may go over 2-4", considerably more over central Minnesota. Far western MN could pick up over 10" of snow by Monday. High: near 20

Tuesday: Partly sunny, much better travel conditions. High: 17

Wednesday: Sunny start, clouds increase, few degrees cooler than average. High: 18

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