The phrase old-fashioned winter has been appropriate to use the season. November is usually a transition from fall to winter and behaved normally this time. Most days featured melting conditions at least briefly until cold temperatures set in late in the month. The landscape had continuous snow cover by the end of the month – again, nothing out of the ordinary.
December is typically a winter month with cold temperatures and considerable snowfall. It was different this time with the temperatures. Extended times of frigid temperatures are usually interspersed with milder weather. In other words, usually there is a December thaw, or two or even three.
Exceptionally cold weather set in later in the month and by the end of December the phrase “polar vortex” was in common usage in the American Midwest and the Canadian media also picked it up. This is not a new event; the term was first used in the mid-20th century. During the northern hemisphere winter it is usual to have an extensive area of exceptional cold somewhere over Siberia, the North Pole and/or Northern Greenland.
Displacement of this large concentration of cold air to central North America has become almost routine this winter. Blame it on the jet stream. The result is that Celsius and Fahrenheit temperatures, especially when wind chill is considered, require little conversion: -40 C = -40 F = cold!
It might be hard to believe but it is relatively warm up at the North Pole right now. Alaska and Moscow are also experiencing warm temperatures – there are concerns in Siberia about a shortage of snow. “Relatively warm” is not the phrase that can be used in Australia where our winter is their summer. Temperatures of 43 C/110 F halted world champion tennis in Melbourne and maximums reached 50 C/122 F in the interior of the country.
What does it all mean about the coming spring and the fishing season?
The good news is that seasonal weather has little memory and an Arctic vortex is unlikely to persist.