Fall Forecast 2016: Next three months and winter preview
Visit this Fall Forecast Guide to the Season for the Fall Forecast, Winter Weather Preview and more.
Monday, September 26, 2016, 9:55 AM - Great news for everyone who looks forward to getting out and enjoying all that Canada has to offer during the autumn season.
Late summer weather will linger into fall across much of the country as near to above normal temperatures are expected to dominate the fall season across much of Canada.
What to expect early on
In the east, summer weather has already lingered into September from the Great Lakes to much of Atlantic Canada. While the inevitable transition from summer to winter will still occur, the pattern will continue to favor warmer than normal temperatures for much of the season. Across northern Quebec, northern Newfoundland and Labrador, temperatures are expected to be closer to seasonal.
In the west, British Columbia saw a cool start to September, but above normal temperatures will become the more dominant pattern for the remainder of the season.
Central Canada, including the Prairies, will see back and forth temperature swings that are typical for the region, especially during the fall. This will result in final numbers close to normal for the season, with the potential for parts of the region to end up just below normal. However, this does not mean that the Prairies are finished with late summer weather as periods of warm weather are still expected at times during the remainder of September and into October.
With the forecast for “above normal” temperatures for so much of the country, we need to keep in mind that fall is a transitional season in which frequent fluctuations in temperature should be expected and “normal” temperatures steadily drop by one to two degrees per week. Warm falls will still have periods of cold weather and vice versa, but our fall forecast seeks to capture to dominant weather pattern for the season.
A false start to winter?
As we look back through history at years that had similar global patterns to our current pattern, it is striking to see how many of those years had a profound period of early winter weather (lasting for 1-3 weeks) during November in the midst of a season that was otherwise quite mild. While most Canadians are accustomed to getting their first taste of winter weather well before December arrives, what we saw during those years went beyond what we typically see in November. In addition, this cold period was then typically followed by a return to milder weather for December.
The consistency of this pattern in the past does not mean that we will see this occur in 2016, but it is something that we will be on the lookout for as we get closer to November. With the Great Lakes running much warmer than normal, any period of cold weather later in the fall would have the potential to bring highly impactful lake effect snow.
Classic fall storms
The fall season is famous for its storms and it looks like this year will bring its share of active weather as near normal or above normal precipitation totals are expected across Canada.
One possible exception is across southern Ontario with below normal precipitation expected just south of the border. While more sunshine than normal with fewer than normal rainy days is expected, storms that do track across this region will have more opportunity to tap into tropical moisture and we expect that will help to boost rainfall totals to near normal levels.
Likewise, the near normal precipitation forecast for southern Quebec, the Maritimes and the south coast of B.C. is expected from fewer than normal rainy days. Ocean water temperatures off both coasts are running are considerably warmer than normal and will likely enhance rainfall amounts (and higher elevation snow for BC) when systems do track across these regions.
An active storm track is expected near the international border across the Prairies and from Northern Ontario to Newfoundland and Labrador with above average rain and eventually snowfall in these regions.
#FallForecast Poll: When does it begin to feel like fall for you? 🍂🍎🍁— The Weather Network (@weathernetwork) September 12, 2016
Winter 2016/2017 preview
After a rather mild winter last year, we expect that this year will bring a return to more classic Canadian winter season from the Rockies to Atlantic Canada, with only B.C. expected to see above normal temperatures for the winter as a whole. The map below shows our preliminary forecast for the months of December, January, and February.
One of the biggest questions at this point is when will we see the pattern change? We expect that the jet stream pattern during the second half of winter will resemble (without duplicating) what we saw during the winters of 2013-14 and 2014-15. This would bring frequent and persistent outbreaks to Arctic air to regions east of the Rockies.
At this point we think that December is more likely to be an extension of the mild fall pattern with the pattern change holding off until later in the winter (similar to what we saw in 2014-15). However, it is possible that the pattern will change more quickly (as it did in 2013). If we see signs of this happening as we finalize our winter forecast for release on November 21, 2016, we will need to expand the area of below normal temperatures.
As we fine tune the forecast as we will also seek to determine whether the focus of the coldest weather will be from Alberta to the Great Lakes or farther east from Manitoba to the Maritimes. Confidence in a cold winter is highest from Manitoba to the Great Lakes with the greatest amount of uncertainty for the Maritimes and especially for Alberta.
Stay tuned as we finalize the winter forecast and add a snowfall forecast for the season. All set for release in November.