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. However, the outcome hinges on the speed of snowmelt.
The northern Rockies, a crucial water source for the Northwest Territories, have witnessed above-average snow accumulation. Despite this, parts of the Northwest Territories faced dry to severely drought-prone conditions, with below-normal precipitation levels.
Recent wildfires in the Northwest Territories were exacerbated by limited snow and rainfall, resulting in low soil moisture and dry vegetation fueling fires. Kate Hale, from the University of British Columbia’s geography department, expressed cautious optimism regarding drought and wildfire conditions in the Northwest Territories due to the significant snowpack in the watershed.
Snowpack measurements in early March indicated levels 110 to 150 percent above normal in the Mackenzie River Basin’s headwater regions. Conversely, snowpack levels around Yellowknife and Great Slave Lake were at 70 to 90 percent of normal.
The upcoming flooding, drought, and wildfire scenarios in the Northwest Territories will be influenced by the pace of snowmelt in the coming weeks and months. If the snow melts gradually, the wildfire risk should decrease this year. However, rapid melting due to hot weather in May could lead to flooding and a challenging wildfire season.
While a single season of above-average snowpack may not fully alleviate long-term aridity effects, it can make a difference. The delayed availability of water from snowpacks throughout the year helps shorten dry periods.
Snowpacks act as natural reservoirs, releasing water downstream during summer. Hale compared the watershed to a series of “buckets,” emphasizing the importance of soil conditions in areas susceptible to wildfires. Burned soils that resist water absorption can heighten flood risks.
John Pomeroy, a University of Saskatchewan hydrology professor, noted that multiple wet years are needed to replenish groundwater fully. Despite the increased snowpack this year, it may only offer a slight reprieve for regions like Great Slave Lake, which have experienced prolonged low water levels.
Hale stated that the above-average snowpack aligns with expected annual fluctuations influenced by climate change. She highlighted the impact of climate change on precipitation and temperature patterns, mentioning La Niña as a potential contributor to this year’s increased snowpack.
Pomeroy emphasized the climate change signals evident in temperature and precipitation variations, noting the trend of longer and more intense droughts and wet periods. The fluctuating climate patterns contribute to challenges like fires, crop failures, and flooding in the region.