1/9/12

Bitter Arctic Air to Pool Over Canada Mid January

NCEP ensemble model members continue to advertise a change in the upper air pattern across the northern hemisphere in mid January. The some of the coldest air of the season is projected to relocate or "drain" from Siberia, Alaska and the Polar regions and settle east southeast over northern Canada over the weekend into next week (14th-21st). This in turn will "recharge the freezer" so to speak up in northern Canada. To check on the evolution of this projected ensemble model pattern, click here.

In addition, this air is expected to migrate south at times into the US. How far south this air is able to infiltrate the US is questionable since the northern Pacific La Nina jet stream has been strong and has acted as a door, shuting off much of the true Arctic air this season. 




 
As the two jets align and merge next week, a strong zonal flow is expected to evolve mid month over southern Canada and the northern US. Occasional ridging in the west is also projected to develop and thus, help divert and phase the Pacific air northeast into the Arctic jet over Canada. This would then create a strong west-northwest jet stream across the northern and eastern part of the country. It is way too early to tell how much of this true Arctic air projected to pool over northern Canada will be caught up in this strong west-northwest flow and make it into Southeast Michigan. Stay Tuned... 

Making weather fun while we all learn,
Bill Deedler - SEMI_WeatherHistorian