The impact of the 1998 North American ice storm is still remembered today, with 16,000 Canadian Forces personnel being deployed to assist the millions of people affected by the power outages. As we are currently experiencing an El Niño year, some are wondering if a similar event could happen again.
To understand what caused the catastrophe in 1998, it’s important to know the conditions that lead to freezing rain. Cold temperatures at low altitudes are necessary, with freezing rain at -5 °C being challenging but possible. When the rain comes into contact with objects, it instantly freezes, causing danger and potential damage to infrastructure.
The 1998 ice storm was a memorable event, with over 100 mm of freezing rain and some areas being without power for up to a month. Meteorologist Réjean Ouimet explains that while the freezing rain coincided with an El Niño episode, it is more accurate to say that the rain happened during an El Niño, rather than being directly caused by it. Two essential conditions are needed for a freezing rain event: warm moisture at high altitudes and cold temperatures near the surface.
El Niño does play a role in creating mild weather in Quebec during winter, as the intense and active jet stream brings humid, tropical air northward. In addition to El Niño, the presence of two high-pressure systems in 1998 also played a crucial role. One high-pressure system pushed cold air down to the ground, while the other created a depression corridor that repeatedly struck Quebec, bringing in warm air. This combination resulted in multiple days of freezing rain.
Other factors, such as a high-pressure system in the Atlantic, also contributed to the 1998 ice storm. It froze the atmosphere and maintained a constant orientation of the weather systems, causing the same type of precipitation to repeatedly affect the same regions for five days. While El Niño is not the only driver of these events, it can still contribute to their occurrence.
While it is possible for a similar event to occur again, all the necessary conditions must align. Cold surface air, warm aloft air, and a series of moisture-laden systems are needed. However, it is unlikely that the magnitude of the 1998 ice storm will be repeated this year, as there are significant temperature differences in the ocean between 1998 and 2023.
In conclusion, while we may see major episodes of freezing rain this year, it is not expected to reach the level of the 1998 ice storm. El Niño can promote milder winters in Quebec, but it does not guarantee the occurrence of a catastrophic storm.
