December breaks records
Last month of 2015 saw the warmest December weather Oshawa has ever seen
El Niño, which occurs when surface water in parts of the Pacific Ocean become warmer than normal, has lead to warmer than normal temperatures in Oshawa. The weather phenomena is part of the reason the area had its warmest December on record, with an average temperature of 4.6 C. The El Niño event is the largest since 1997-1998, seen here in a sea surface height map from NASA. The warmer the ocean’s water gets, the higher the water rises.
By Graeme McNaughton/The Oshawa Express
For those that thought last month was a little warm, you were right. In fact, it was warm enough to break records.
However, one meteorologist is using stronger words than that.
“We’re using words like shattered and destroyed. We saw records fall all across the province,” Geoff Coulson, a warning preparedness meteorologist with Environment and Climate Change Canada, tells The Oshawa Express. “It was one for the record books. For Oshawa itself, we ended up with an average temperature for the month of December of 4.6 C. To put that into context, the long-term average temperature for December is –1.2 C. So, it’s way above that value.”
Coulson says that the current record for the Oshawa area for warmest average December temperature was set back in 2006, when the average was 2.8 C.
While it isn’t clear what exactly led to Oshawa’s higher than normal temperatures last month, one of the main suspects lies to the west. Far west.
“One of the main reasons was we knew going into this fall and winter that we were going to be dealing with one of the strongest El Niño events to occur since detailed record keeping began in 1950,” Coulson says.
According to Environment and Climate Change Canada, El Niño occurs when surface waters in the eastern tropical regions of the Pacific Ocean become warmer than average, leading to a changing ocean pattern that causing a shift in atmospheric circulation.
This latest occurrence is to blame for drier than normal conditions in Australia, Indonesia and the Philippines, and wetter and cooler than normal conditions in some parts of the southern United States and southeast South America.
“The only other El Nino that rivals it in terms of the strength of this one occurred back in 1997, 1998. And when we do get these El Nino events happening, it can tend towards a milder than normal fall and winter for the Great Lakes basin,” Coulson says. “I’m sure it played a role in it, but I’m not quite sure how much of a role or what other factors might have been in play. Certainly, it was something that we thought would give us milder than normal conditions, but nothing I had seen in the lead up to the month had indicated we would be breaking the records by as much as we ended up doing.”
This month, while it appears to be milder, will likely not be breaking any records.
“We’ve already seen some colder than normal temperatures, but this weekend we’re looking at getting into somewhat milder than normal conditions,” Coulson says, adding a projected cold snap next week will be followed by a return to seasonal temperatures.