A colder and wetter winter in the Canadian Rockies this year has led to near-record snowfall, potentially benefiting the Northwest Territories by reducing drought and wildfire risks. The amount of snowmelt will crucially impact the outcome.
The northern Rockies, a significant water source for the Northwest Territories, have experienced higher-than-average snowfall. However, the Canadian Drought Monitor indicates that parts of the Northwest Territories faced dry to severe drought conditions by the end of March, with precipitation levels well below normal in many areas.
In recent years, wildfires in the Northwest Territories have been exacerbated by limited snow and rain, resulting in low soil moisture and dried-out vegetation fueling fires during the summer and fall. Kate Hale from the University of British Columbia expresses cautious optimism regarding drought and wildfire prospects in the Northwest Territories due to the substantial snowpack in the upper watershed.
Snowpack estimates in early March were 110 to 150 percent above normal in the headwater regions of the Mackenzie River Basin. However, snowpack levels in Yellowknife and around Great Slave Lake were only 70 to 90 percent of normal.
The future conditions of flooding, drought, and wildfires in the N.W.T. depend on the speed of the snowmelt in the coming weeks and months. If the snow melts at an average rate, there should be relief from wildfire risks this year. Conversely, rapid melting due to high temperatures in May could lead to flooding and another challenging wildfire season.
Hale notes that while significantly above-average snowpack may not fully alleviate long-term aridity, it could make a difference. The gradual melt of snow ensures water resources are available later in the year, potentially shortening dry periods.
Snowpacks act as natural reservoirs, supplying downstream water during the summer. Hale compares the watershed to a series of “buckets” that store water for different purposes, emphasizing the importance of soil conditions in wildfire-prone areas.
John Pomeroy from the University of Saskatchewan emphasizes that it usually takes multiple wet years to replenish groundwater fully. He mentions that the low water levels of Great Slave Lake have persisted for years, suggesting that this year’s snowpack may offer only slight relief.
Hale affirms that this year’s above-average snowpack aligns with expected fluctuations influenced by climate change. She mentions that as temperatures rise and weather patterns become more erratic, there can be variations in precipitation levels due to phenomena like La Niña.
Pomeroy underscores the impact of climate change on temperature and precipitation variability, leading to longer and more intense droughts and wet periods. The shifting climate patterns contribute to extreme events like fires, crop failures, and flooding.