An End to La Niña: Warmer Conditions Ahead?

The Acting Lead of PCIC’s Regional Climate Impacts theme, Dr. Charles Curry, was recently interviewed by the Vancouver Sun for an article on the World Meteorological Organization’s warning about the potential for higher temperatures and heat records over the next year or so. The concern is that the possible development of El Niño conditions in the coming months, on top of the background trend in increasing temperatures from global warming, might exacerbate heat extremes—what the WMO has termed a “double whammy.” “When you already have a slightly warmer than normal global ocean and greenhouse gas forcing the steady warming of the climate,” Dr. Curry stated, “… it stands to reason that you have a higher probability of extreme heat events and probably extreme drought in areas already susceptible to that.” He further explained that regions of BC that are prone to dry summer conditions, such as BC’s interior, might experience exacerbated dry conditions were an El Niño state to develop. In BC, El Niño tends to result in warmer than normal conditions, especially in the late winter and spring.

The El Niño Southern Oscillation (ENSO) is a climate pattern with global effects that results from periodic variations in the sea surface temperature across the equatorial Pacific Ocean. Its influence extends far beyond this region, however, affecting seasonal climate around the world, especially in areas bordering the Pacific Ocean. Since mid-2020, ENSO has been in a La Niña state, which normally results in cooler and wetter than normal conditions in BC. It recently transitioned to a neutral state, which often indicates El Niño conditions may develop in subsequent months. The most recent forecasts (issued in April) from the National Weather Service’s Climate Prediction Center and Columbia University, which informed the WMO update, suggest an increasing probability that El Niño will develop as the year goes on, reaching approximately 70% by autumn. The most recent seasonal forecasts from Environment and Climate Change Canada, also issued in April, suggest a high probability of warmer than normal conditions across BC over nearly all of the forecast periods, including the next 1-3 months and 2-4 months, and warmer than average conditions being likely over much of the country for all forecast periods over the next 12 months. After an El Niño develops, its effects on global and regional climate can take up to a year to become apparent.

The Province of British Columbia has a page on extreme heat hazards that outlines some of the steps that can be taken to prepare for and deal with extreme heat, as well as the resources that are available for more information.

Read the article in the Vancouver Sun.

Read the WMO’s Update.