Christmas Mega Storm 2009: Right on track

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Twin Cities NWS highlights heaviest snow and ice areas.

It appears our major Christmas storm is still on track for heavy snow. The only remaining question appears to be: How much?

Update 12:01 am Wednesday:

The evening model runs are brining warmer air and the rain/ice/snow transition zone very close to the Twin Cities on Christmas Eve. This could produce a mix of sleet and freezing rain before things change back to all snow Christmas Day.

The result is the same, a travel mess. But it could reduce storm total snowfall amounts accordingly spending on how much of the precip falls as sleet of freezing rain. It still looks like over a foot of snow is likely in the metro. Areas that see all snow still look to produce 12" to 18"+ with some possible totals over 20" by Sunday.

Updates on Morning Edition at 6:45, 7:45 and 8:45.

PH

The latest model runs continue the trend of bringing a deepening, slow moving system to the Upper Midwest from Wednesday night into early Saturday. Travel may already be slick early Wednesday to the south in places like Omaha and Des Moines.

Here are some of the latest model and forecast trends.

-The big picture still brings snow and difficult travel conditions to the entire region Wednesday evening into early Saturday.

-There may be freezing rain and ice east and southeast of the Twin Cities from Eau Claire to Rochester and La Crosse into eastern Iowa and much of Wisconsin.

-As the storm moves closer and gains strength, the heaviest snowfall rates may occur between 6pm Christmas Eve and midnight Christmas night. (Saturday morning) Snowfall rates of one half to 1 inch per hour may occur during this time.

-It still appears that the long duration of 48 to 60 hours of snowfall combined with the deep moisture and intensity may produce widespread snowfall totals of 12" to 18"+

-Some forecast models are cranking out over 2" of liquid for this storm. That can translate into over 20" of some for some areas.

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Latest Cobb technique snowfall forecast cranks out a possible 20" for the metro.

The bottom line is, regardless of eventual snowfall totals, travel will be difficult to impossible in much of Minnesota, Iowa, Nebraska, the eastern Dakotas and Wisconsin from Wednesday evening into Saturday.

I am finalizing snow predictions for the metro pending tonight's model runs. Here's a teaser...if the storm stays on track we could break records. This could be one of the biggest snow storms for the Twin Cities in years.

Stay tuned, and travel safely!

PH