This winter (so far) is blessing & curse
Ask ten people what they think about our winter so far and you will likely get a split decision. Some love the warmth and lack of snow while others hate it. No matter how you feel about it, this winter has been one odd duck, mainly due to the extended positive phase of the North Atlantic Oscillation NAO). As I have written about in previous blogs and video, the positive NAO has been the singular biggest influence on a rather dry and mild winter for much of the country.
Thanks to the folks at the National Weather Service-Milwaukee/Sullivan, this is the third least snowiest beginning to the snow season. Consider the list below. It contains the least amount of snow recorded in Milwaukee through today, January 9:
Note to frustrated winter weather fans: after a slow start to winter snowfall in 2001-2002, once we got past January 9, 2002, the weather turned more winter-like. Total snowfall for January 2002 was 13.1″, February 4.2″, March 13.0″,and April 3.6″.
The NAO fluctuates in value based on the strengh of the Icelandic Low and the Azores High, both large pressure systems in the eastern Atlantic. As I have often argued, this is why seasonal forecasts cannot be taken seriously. Every autumn we hear predictions about the upcoming winter, but we seldom hear any follow-up when those predictions go bad.
This warmth has saved on our home heating bills as well as the cost of winter clean-up for municipalities (salt and plowing). But any business that relies on snow and cold has been in a world of hurt. It even comes down to stores that sell winter clothing. Everything changes when we have an unusual winter like this.
Can things change? Yes, and at least in the near term, the next 10 days look to be quite different. It begins with a cold front pushing through our area Wednesday night. The jet stream buckles and allows arctic air to surge south out of central Canada. This will send our temperatures from above average to below average in a hurry.
However, beyond the next 10 days, who knows? Long range global computer models have their limitations, and I don’t put a lot of faith in them beyond a week or so.
The trend for the next 10 days is a strong split flow aloft, meaning the subtropical jet stream will help guide strong storm systems loaded with moisture across the Gulf states and into the northeast U.S. Meanwhile, the polar jet stream dives south across the upper Midwest and puts us in the chill.
The northern branch of the jet stream remains over the northern third of the country through all of next week, meaning we should receive Alberta Clipper weather systems that originate in the Alberta province of Canada and move rapidly east-southeast into Wisconsin. This will bring us areas of light, dry, fluffy snow every few days along with a continuation of cold air.
GFS numerical prediction model output for next Sunday, January 15, 2012, showing a wet storm system in the southeast U.S. while we remain cold but quiet in Wisconsin.
GFS numerical prediction model output for Friday, January 20, 2012, showing an active northern branch of the jet stream. This would produce Alberta Clipper type storm systems over the northern third of the country. For Wisconsin this would produce cold air and periods of light, dry, fluffy snowfall.