El Niño has put Canada's weather on pause
Canada has experienced unusually calm weather recently due to a weaker jet stream, the influence of El Niño, and dominant high pressure systems, with these conditions expected to persist into late September
The weather across Canada has been unusually calm recently, and this can be attributed to several atmospheric factors typical for early fall.
Reduced sun angles and shorter daylight hours lead to less atmospheric instability, but broader weather patterns are also at play.
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Weak jet stream contributing to calm conditions
The jet stream, which drives much of Canada's active weather, is weaker at this time of year. As summer transitions to fall, the temperature contrast between the tropics and the Arctic is at its annual low point.
With a weaker pressure gradient, the jet stream loses much of its strength, delaying the arrival of more dynamic fall weather systems.
El Niño’s influence on weather patterns
The ongoing El Niño event has also impacted the jet stream. It has strengthened the southern U.S. jet stream while limiting interaction with northern systems, reducing the potential for widespread active weather across Canada.
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High pressure dominance
In eastern Canada, a strong heat dome in the U.S. influenced conditions, while in the West, a high pressure system brought frost advisories and cooler air.
These high pressure systems have been a key factor in suppressing weather activity nationwide.
Long range outlook
This quiet weather is expected to persist into late September.
The jet stream should begin to strengthen later in the season, but El Niño's influence may still shape a more stable pattern in the coming weeks.