The “Spring Dip” Explained: A Hidden Wildfire Hazard in Western Canada
As winter fades and spring emerges in Canada, a lesser-known but critical phenomenon known as the "Spring Dip" in wildfire risk rears its head. This seasonal spike in wildfire danger occurs every year, yet this spring, the conditions are particularly precarious due to unusually low winter snowfall and ongoing severe drought conditions.
The historic 2016 Fort McMurray wildfire occurred during spring dip conditions.
Understanding the "Spring Dip"
The Spring Dip refers to a period during early spring when the risk of wildfires increases dramatically across parts of Western Canada. This risk escalates after the winter snow has melted but before the new season’s growth has begun to green the landscapes. During this window, last year's dead vegetation—dry grasses, leaves, and branches—has very low moisture content and is extremely flammable.
The Inevitable Spring Dip
Interestingly, the Spring Dip is a natural annual event, not solely dependent on adverse weather conditions like drought or low snowfall. It occurs because the melting snow from winter evaporates or runs off before substantial new growth can take place. This leaves plenty of dry material on the ground which can easily catch fire.
The Elements of Surprise
One of the most challenging aspects of the Spring Dip is its ability to catch homeowners and local authorities off guard. With the memory of cold, snowy winter still fresh, nighttime temperatures that still may fall well below zero and no wildfires having occurred yet to signal the dry danger, many fail to recognize the high risk of severe wildfires during this time.
Amplified Risks This Year
This year, however, the Spring Dip is particularly concerning for Western Canada. The region has experienced a winter with significantly lower than average snowfall combined with persistent drought conditions. These factors mean that the ground and leftover plant material from last year are drier than usual, making them more likely to ignite and carry fire.
Current Weather Conditions and Wildfire Risk
The current weather patterns across Western Canada are exacerbating these risks further. With continued dry conditions and sporadic rainfall not enough to reverse the drought, the “green up” is delayed. In the meantime, the environment remains primed for wildfires.
Historical Perspective and Current Concerns
Historical data shows that many significant wildfires in Western Canada have occurred during or just after a Spring Dip period. For instance, the catastrophic Fort McMurray wildfire in 2016 and Slave Lake wildfire of 2011 were fueled by similar conditions during similar time frames —preceding low snowfall and existing drought had left the landscape unusually dry and highly combustible.
Conclusion
The phenomenon of the Spring Dip is a critical aspect of seasonal wildfire risk management in Western Canada. While it is an annual event that can occur under normal conditions, this year's combination of low snowfall and severe drought has made the situation especially dangerous. Understanding these dynamics is crucial for recognizing the heightened risks and urging vigilance during this vulnerable period for wildfire activity. Ultimately, this underscores the importance that now is the time to prepare for wildfires by investing in structure protection kits.