If you’ve found yourself tossing an extra blanket on the bed at night or clutching that coat a little tighter when you strike out into the day, there’s good reason for it.
This January has some bite to it, says Shawn Allan of AMEC Earth and Environmental Ltd. The final numbers for the month may not be in, but the writing is on the wall — and it’s written in frost.
“If the forecast pans out more or less the way we project through the end of the month, this will probably be the coldest January in the last 10 years,” says Allan.
It might not beat the winter of 2003, though. Some people are still getting the chill out of their bones from that notable season.
“The winter of 2003 was notable. It was a bitterly cold winter right across the board,” Allan says.
The January average temperature in 2003 was -4.8 C. The average for this January thus far is -4.7 C. The temperatures this month have also been noteworthy in that we’ll probably have 12 nights where the temperature dropped to below -12 C, Allan predicts. Something that hasn’t happened in the last 10 years, he says.
But don’t break out the “we’re so tough” attitude just yet. Those who came before us really did have it harder. This may be panning out to be a chilly month but in the range of historical weather patterns, it’s warming up.
“The winters have been noticeably warmer in the last 10 years, there’s no question,” says Allan.
The normal average temperature for January is -4.8 C. So we’re average this year, or maybe slightly warmer than average.
“We haven’t had one single January in the last 10 years that was colder than average and this one is not likely to be either,” Allan says.
The warmest winter in the last 10 years was in 2011.
The temperatures haven’t been noteworthy at all this winter when you look at the past 60 years or so, Allan says. Snowfall, on the other hand, is notable when you look at the past 10 years or so.
About 160 cm of snow has fallen so far this winter, even though December had about half the amount considered normal for that month.
By far the bulk of snow fell in January, with roughly 110 cm so far this month, much of that in a wallop of a storm that blew through on Jan. 11. The average snowfall for January is 80 cm, says Allan, putting what’s on record thus far for this month well above that number. You have to go back to 2005 to find a January as snowy as this one, Allan says.
Allan says the public may have noticed more sunny winter days over the past few years and less of that foggy, damp winter weather the Avalon is notorious for. That’s because the atmosphere has been a bit different the last couple of winters, he says.
“It’s definitely been the case over at least the last year that the weather systems have been moving in and out more quickly. There’s been more high pressure. There’s been more fair days. And what that translates into is that we tend to get more colder nights and more of a temperature extreme.”
Allan says what’s been lacking in winters in the recent past is very cold Arctic air.
”This January in particular there’s been much more cold air available in the Arctic regions to be pulled down over Newfoundland. In winters past, typically all that cold air, that bitter freezing stuff, was locked up in Siberia and Eastern Europe and it wasn’t really found over the Arctic region of Canada.”
This January, the atmosphere pattern allowed that cold air to spill across the pole and into the Canadian Arctic regions, so it’s more readily pulled down over our area, Allan says.
A few weeks back we experienced something called a sudden stratospheric warming, he said — an event that occurs about 50 km up in the atmosphere and involves the polar winds suddenly weakening or even reversing.
“For reasons not understood easily, meteorologists typically see much more cold develop a few weeks after an event like that,” he says.
Describing what this winter has been like in relation to the past is a cakewalk compared to predicting where it’s going, says Allan.
“Long-range weather prediction is more of an art than a science,” he says, adding that the people who do it for a living are rarely more than about 50 per cent accurate.
“Which is another way of saying it’s more chance than anything else.”
Something called the North Atlantic oscillation really drives the outlook here, Allan says.
“It pretty much controls if we have above or below average temperatures and snow.”
It’s a huge area of low pressure offshore that Allan defines as the difference between high pressure over the middle of the Atlantic Ocean and low pressure in the Greenland area.
It has a dramatic effect on the storm tracks and whether there will be precipitation during a weather event, he says.
Unfortunately, it’s not predicatable beyond about two weeks, so meteorologists have another tool for long-range weather predictions: the history books.
By recognizing the atmospheric state that’s driving 2013, you can look for similar atmospheric states in years gone by, says Allan. And there are two: one in 1963 and another in 1967 match closely to this year’s. In those years, the temperatures experienced in February were comparable to what we’re getting in January this year, says Allan.
So with the past as a map, Environment Canada and the national weather agencies in the states are both predicting near to above normal temperatures for the remainder of the winter, and near to below normal precipitation.
Allan has been looking at the data to make his own prediction.
“It looks to me like the rest of the winter is going to be slightly above normal in temperature but it will still feel cold. That’s the way I would characterize it.”
He adds that he doesn’t think February will be perceived as a warm month.
“So I’m thinking February is going to be not an abnormally warm month, and snowfall-wise I don’t think that it’s going to be a particularly snowy month.”
It may be best to keep that extra blanket on the bed for a little longer.