Updraft: November 4, 2010 Archive

Cold air lags: Lack of Canada snow cover

Posted at 8:42 AM on November 4, 2010 by Paul Huttner
Filed under: Hurricanes, Snow

It's November and finally a real Canadian air mass is surging south. But it's still above freezing and 10 degrees above average in most of Minnesota.

It seems Canadian cold fronts are just not what they used to be so far this fall.

A lack of snow cover over much of Canada so far this month may be the reason why our first November cold front features temperatures that are still at or above seasonal averages.

Air masses absorb and retain the properties of the regions they are born in and move over. Think of snow cover as a big block of ice...if you pass your hand over the top you can feel the cooler air. No snow, no cool air. Our air mass coming south from western Canada has travelled over bare ground on the trip to Minnesota.

If you travel northwest from Minnesota the ground is snow free for at least 1,000 miles.

A milder westerly air flow returns this weekend, and the lack of snow in the Upper Midwest will allow temperatures to recover more quickly than they might in other years. Hunters will enjoy mild conditions in the field this weekend, but will not have the benefit of "tracking snow."

East Coast swamped:

Low pressure east of Washington D.C. is dumping heavy rainfall to much of the eastern USA today. The space shuttle launch was scrubbed by bad weather today in Florida. Heavy rain is delaying flights in the northeast.

Tropical trouble for Haiti:

The Atlantic Hurricane season is not done just yet.

Tropical Storm Thomas may become Hurricane Thomas in the next 24 hours as it rakes Haiti through Friday. The storm will likely dump 5 to 10" (with isolated 15" totals) of unwelcome rainfall to the mountainous nation, which is still reeling from earthquake damage.

PH