After a few years of dormancy, the El Niño climatic phenomenon has made a comeback since July in the Pacific Ocean. According to the American Oceanic and Atmospheric Observation Agency, it has a 71% probability of being of “strong” amplitude and a 95% probability of lasting until March 2024. In Quebec, its effect is generally limited, but it could still slightly influence temperatures and bring storms.
What is El Niño?
El Niño is a natural climatic phenomenon, which occurs every two to seven years and generally lasts 12 to 18 months. The surface waters of the Pacific Ocean are warmer than usual, creating chain reactions that affect the global climate.
El Niño can cause or amplify storms, droughts or floods in different parts of the globe. Here in Quebec, it would have been a factor – among others – having created the conditions conducive to the ice crisis of 1998.
The opposite phenomenon is called La Niña, which causes a cooling of the Pacific.
According to André Monette, chief meteorologist at MétéoMédia, “the effects [de El Niño] are not direct on Quebec, and not all El Niños have the same consequences.”
That said, “often what it brings is the first rather early signs of winter. We find ourselves a little disoriented. » We could therefore find ourselves with a cold spell or even snowflakes earlier than usual this fall.
On the other hand, it is not uncommon for this to be followed by a mild spell and for the real onset of winter to be delayed. This is what happened in 2015 during a previous El Niño: the mercury rose to 20 degrees just before Christmas in La Belle Province.
Winter maybe a little milder…
Temperature-wise, Quebecers should not hold out too much hope for a less harsh winter thanks to the heat of El Niño, according to Jean-Philippe Bégin, meteorologist at Environment Canada.
Historically, for the months of December to February, El Niño has been associated with milder temperatures in Canada, but this correlation is stronger in the west of the country than in the east. In Quebec, “it’s more mixed”.
Average temperatures are “either slightly above normal, or near normal.” We can therefore predict a “typical winter”.
Conversely, this summer, historical data predicted less heat and more coolness in the Belle Province under El Niño, and this is what happened, points out Jean-Philippe Bégin.
Where El Niño could play spoilsport during the winter months is in the United States, up to the Gulf of Mexico and along the East Coast. Humidity is abundant there, which can generate weather systems. These depressions can then take trajectories leading to Quebec.
“What that means is that we could have, often in this context, more nor’easter type storms […] which are rapidly intensifying along the American east coast,” underlines Mr. Bégin.
Snowbirds could taste it
In the United States in winter, El Niño generally brings colder and rainy weather to the South, including Florida. Quebec snowbirds are therefore exposed to possibly more frequent showers and below-average mercury.
However, contrary to popular belief, El Niño tends to reduce the number of hurricanes that form in the Atlantic, according to the American agency.