In many regions across the country, Canadians faced rather unusual conditions for the long-awaited months of summer, from cooler temperatures in Central Canada to warm, dry conditions in the West. Central Canadians experienced a storm track that brought in below average temperatures and more rainfall than usual. The see-saw effect of the jet stream also brought warm and dry conditions to Western Canada where forest fires continue to be battled due to the conditions.
The positioning of the jet stream was to blame for the weather conditions in July with a return to a more typical summer jet stream pattern for August. There is no definitive explanation for why the jet stream took the pattern that it did. Amateur explanations have included ice on Hudson Bay well into July, a lack of sun spots, and global warming. None of these hypotheses offer enough scientific proof to be considered a reasonable explanation. They may be contributing factors or, in the case of the ice on Hudson Bay, be caused by the situation they are meant to explain. Climatology is a complicated science where often there is no one explanation.
Another phenomenon possibly responsible for our unusual summer weather is El Niño. El Niño is known to impact the jet stream and July was the first month that El Niño conditions were observed. The El Niño conditions observed were still weak but this and many other factors probably resulted in a jet stream that meant hot, dry conditions for BC and wet, cool conditions for Eastern Canada.
Moving into the transitional fall months of September, October and November, Canadians can expect the developing El Niño conditions in the Pacific Ocean to have an impact on the North American weather patterns for the next six to twelve months. The jet stream is forecast to take on more of a zonal west to east pattern this fall, meaning a more rapid flow of systems across the country. Overall, the jet stream will trend further north for the beginning of the season, however as the season progresses, expect it to move south as fall comes to a close. Overall, Canadians can anticipate temperatures from British Columbia to Ontario to be above normal. Near normal precipitation is expected for most of the country with a few pockets of above normal precipitation. Normal temperatures or precipitation are an average based on 30 years of data.
'The jet stream pattern we saw throughout the summer months is gradually transitioning, and our seasonal forecast team is predicting above average temperatures this fall for nearly all of Western Canada,' said Chris Scott, Forecast Operations Manager with The Weather Network. 'Many Canadians in Eastern Canada have been hoping the cooler than normal summer temperatures means that summer has been delayed into the fall months – while temperatures are forecast to be close to normal, there is an opportunity for some stretches of warm weather in the first half of the season.'
British Columbia: Coastal areas of British Columbia can expect near normal temperatures for the next few months. Interior and eastern portions of the province will see above normal temperatures for the season. Pacific storms moving from the coast through the central Interior will bring above normal precipitation.
Prairie Provinces: Temperatures for a significant portion of the 3 provinces will average above normal. The far north of Saskatchewan and Manitoba will see temperatures closer to normal. Most of the region will see normal precipitation values leading into winter.
Ontario and Quebec: Most of Northern Ontario will see above normal temperatures, while Southern regions of the province can expect near normal temperatures. The majority of Quebec will experience temperatures near normal. Storms from Western Canada and the US Central high plains will tend to bring more frequent precipitation to Northwestern Ontario. Near normal precipitation is expected for the rest of Ontario into Quebec.
Atlantic Canada: Temperatures in Atlantic Canada are forecast to be near normal for the fall months. While the Maritimes can expect near normal precipitation, the position of the jet stream coupled with moisture from tropical systems may result in above average precipitation for Newfoundland.
With El Niño conditions present in the Pacific Ocean, fewer tropical storms and hurricanes are expected to form in the Atlantic Ocean. However, residents of Eastern Canada should be prepared for the remnants of tropical systems throughout the fall months. 'El Niño tends to reduce the number of Atlantic hurricanes, but past seasons have shown that destructive storms can still form during El Niño years,' said Chris Scott.