Before I get to last winter....An expanding area of heat and humidity will spread toward the lower Great Lakes and eastern U.S. later this week and into the weekend. Right now, it looks like extreme southern parts of southwestern might get into the hot stuff, but it's going to be close with a warm front draped NW-SE across the region. Along the front there will likely be a few rounds of heavier thunderstorms through the weekend.
Speaking of this weekend, there will be a tremendous contrast from the Great Lakes to the Prairies. See below........
The incredible warm winter of 2011-2012
According to Environment Canada, the winter of 2011-2012 was the third warmest on record. The warmest winter in Canada was 2009-2010.
Obviously, a majority of long range forecasts, including yours truly were well off the mark. The biggest bust was out in the Prairies where a clear majority of analogs and model data indicated a cold winter. Mother nature had other plans and basically took a pass on the winter as temperatures averaged well above normal.
La Nina was clearly factored into the forecast, but the typical cold influence of La Nina on western Canada was greatly overshadowed by an dominant and unusually strong positive Arctic Oscillation (AO).
The +AO helped create an unusually strong west to east Pacific jet, which was farther north than normal due to a lack blocking to the north. The strong jet meant that mild, Pacific air could cut across southern Canada and the U.S. with ease, while the Arctic air remained over Alaska and the Yukon Territory.
The strong jet also meant that winter storms tracked much more quickly from west to east, limiting their chances to strengthen and reducing the amount of precipitation in many areas as the duration of storm precipitation was reduced as storms came and went fairly quickly.
Are the Canadian winters getting warmer?
Over the past 65 years the answer looks like a convincing yes. The red, dashed line is the linear trend. Image courtesy of Environment Canada.
An interpretation of the latest ECMWF weekly long-range forecast output...
Clipper-like storm system will bring light snow to eastern Canada into tonight followed by another round of locally heavy lake-effect snow.
More about the lake-effect snow and upcoming weather pattern.
Arctic invasion will lead to a widespread, major lake-effect snowfall.
Light to moderate snowfall from the storm then an outbreak of heavy lake-effect snow in parts of Ontario as very cold air and strong winds inundate the region Monday night into Wednesday.
Latest forecast model data and teleconnections support the idea that the widespread cold pattern will gradually fade way during the last week of the month.