Let’s get to the basics of why our winter was so historically warm. It’s all thanks to the major El Nino which was not a super one, but very strong – about 2.45 degrees C above normal – with the highest pick of the El Nino being 3.45 degrees above normal.
It did not last than long only, one month – for there to be a super El Nino you need three, or warmer sea surface temperatures for three months in a row, yet it was one of the strongest since the 2016-2017 year.
The super El- Nino of 2016-2017 was not the strongest of all time; the strongest El Nino ever recorded was in the 1980s, the second was 1997-1998 super El Nino. Both were 0.25 to 0 35 degrees above the one that happened in 2016-2017, so the El-Nino that just happened was the fifth strongest on record.
Now let’s get into why the winter was so mild. It’s all thanks to three factors.
First, an unusually strong Pacific jet. A Pacific jet is when warm flows from the Pacific Ocean eastward across the country, allowing mild temperatures to dominate the weather pattern and with the El Nino being amplified, the weather system gets to the second cause, the so-called fall super El Nino, amplifying the Pacific jet flow.
The third reason was a stronger polar vortex. The stronger the polar vortex, the less time it buckles and the less the coldest Arctic temperatures invade Canada and USA, which is why the winter was the third warmest of all time.
Also of note was the historical cold snap that happened in January 2024 with temperatures reaching the mid -40s and near -50 – that was just a wake-up for the polar vortex. That why this winter was called “the winter that did not come.”
Let’s talk about a forecast for Spring 2024.
There are three factors that will make the first half of spring colder and snowier than normal with the last snow happening the last week of April. Multiple events of cold from the north, most common in March and the first week of April with more cold and warm swings and snowstorms happening in March and early April and May being much stormier and slightly cooler than normal.
That’s great news for the fire season after last year’s all-time most active fire season. Will that repeat? Yes, but only the start of the fire season but the rest of the fire season will fade to very low fire season for summer and fall, because theirs the opposite type of El Nino, the so-called La Nina.
Now the La Nina of 2024-2025 will possibly be the strongest of all time, much greater than this current El-Nino.
That is not good for the winter of 2024-2025 but I will get to that later.
Our summer could be the driest summer on record but is more likely to be the wettest summer on record.
So with the fire season mostly going well below normal fire season, this should not be a repeat of last year.
So what events are we going to have to be concerned about? More flooding and severe thunderstorm events with flash flooding, vivid lightning, strong to damaging winds and tornado outbreaks due to the incoming La Nina.
So enjoy the weather; it’s the only weather we got.
Jed Laidlaw is an amateur meteorologist living in Athabasca.
