Winter Storm: Getting closer

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Twin Cities NWS weather story paints areas of ice and heavy snow.

The Christmas Mega Storm of 2009 is not ready to pull the trigger just yet, but it's definitely taking aim. Here are some current rends with storm thinking as new model runs come in.

-The big picture remains the same. Expect snow, ice, winds and poor travel conditions in the entire Upper Midwest from Wednesday evening into Saturday. The storm will get going earlier in Iowa and Nebraska, where travel may be difficult as early as this evening.

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-The latest model runs jog the storm center slightly more to the west on Christmas Eve. This may suck in enough warm air to briefly change snow over to ice as far west as the Twin Cities Christmas Eve, before changing back to all snow. It may also mean a significant ice storm is possible from Eau Claire to Rochester and La Crosse and much of eastern Iowa.

-The "sweet spot" for heaviest snow appears to be from the west metro to Willmar, to Mankato south to the Iowa border near Worthington. These are the areas most likely to see snowfall totals of one foot or more.

-It appears snowfall will spread north from Iowa Wednesday morning, and the first waves of snow may approach the metro late Wednesday afternoon into early evening.

-The heaviest part of the storm and highest snow and ice intensities still appear to be the second half of Christmas Eve through Christmas Day.

-I still think snow totals of 12" to 18"+ are possible in the heavy snow axis by Saturday afternoon. Exactly where this axis sets up is still a little uncertain, but it is looking more like a Worthington, to Mankato to western Twin Cities' line.

The Cobb Technique is one of the methods for forecasting snowfall amounts. Check out the output for Twin Cities Airport below. The overnight model runs suggest as much as 18" for the Twin Cities. The run for Eden Prairie suggests an incredible 20+" total !

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Cobb output cranks out 18" for the Twin Cities by Saturday.

We'll get two more main model runs before the storm gets cranking Wednesday evening.

Stay tuned for changes and updates.

PH