The Department of Environment and Natural Resources' FireBoss aircraft sits at the Norman Wells airport in June 2020. Sarah Pruys/Cabin Radio
As you would expect, the NWT’s 2021 fire season is off to a slow start. There is instead flooding in some regions after heavy winter snowfall across much of the territory. The exceptions are the Beaufort Delta and parts of the Sahtu.
So far this year, there has been just one wildfire: a human-caused fire which started and was extinguished on May 24 in the North Slave. It was so small that the GNWT’s fire map still records zero hectares burned this season.
As of Tuesday, fire danger was rated high in the Beaufort Delta, medium in the Dehcho, North Slave, and South Slave, and low in the Sahtu.
In Wood Buffalo National Park, which has a separate fire management system under Parks Canada, the fire danger is high but no wildfires have so far been recorded.
The territory’s wildfire operations manager, Richard Olsen, started the first wildfire briefing of the summer by saying the available data did not allow “a great amount of confidence” in his forecast for the season ahead.
So while he did provide month-by-month projections, things could change.
How the fire season plays out depends on a number of factors, he said, including the amount of precipitation the NWT gets – which becomes less accurate the further into the future the forecasts look.
“In some areas, after two or three weeks without rain, we’ll certainly be in conditions where we can expect some kind of extreme behaviour,” said Olsen.
The changing climate is also impacting the accuracy of wildfire forecasts. Olsen said.
Fire forecasting involves “a lot of assumptions based on what’s happened before,” he told reporters, but as weather patterns change it becomes more difficult to make those assumptions.
For example, last summer, the Arctic vortex broke into a couple of smaller systems, causing airflow and associated weather systems to change direction and behave unexpectedly.
In June, the forecast suggests below-average fire risk across much of the NWT with the exception of the Beaufort Delta, which could see a more active month.
By July, the southern side of Great Slave Lake may have dried out and might have a higher chance of severe fires.
August is projected to be warmer and drier than normal in the Dehcho, putting it at higher risk of fires later in the season – but the rest of the NWT will likely be cool and wet.
Beaufort Delta dry, other regions ‘saturated’
“The NWT overall is not really experiencing much in terms of significant drought,” Olsen said.
However, the Beaufort Delta and parts of the Sahtu are starting to appear “abnormally dry” due to lower snowfall.
The picture is completely different in the southern NWT, particularly the Dehcho and South Slave, where there remains plenty of standing water in forests.
“A lot of the fuel that is available to burn is saturated, so it’s going to be some time before some of these sites dry out and start to see … fires that have a large chance of growing big,” Olsen said.
He said the Dehcho and South Slave regions have the lowest drought code numbers – the amount of moisture in burnable fuel – “for as long as most of us can remember,” meaning the regions are at unusually low risk of a fire starting.
“We’ve never really seen these kind of conditions starting in the spring,” said Olsen.
When’s the next major fire season expected?
With the Covid-19 pandemic ongoing, the NWT will again try to avoid bringing crews from outside the territory to work on larger fires. That means there is a plan to “find fires small and put them out as soon as possible,” Olsen said.
To do so, the NWT will employ 34 four-person crews this summer, a three-crew increase on past years.
There will be one extra air tanker group and one more detection aircraft than usual. The lower number of commercial flights during the pandemic means the NWT needs extra eyeballs in the air to spot fires that commercial pilots might normally report.
In 2020, 70 wildfires burned 21,139 hectares. In 2019, 145 wildfires burned 105,000 hectares. In 2018, just 59 fires burned 16,000 hectares.
Typically, the severity of forest fire seasons operates in a cycle. In 2013 to 2015, the territory experienced some of its most active fire seasons on record before things began to slow down.
“In a general sense, it seems to be about every 10 to 15 years we get some drying events that occur,” said Olsen.
“But we do need to be mindful that the climate is changing and there are predictions we may actually see changes within our fire regime, especially in terms of the intensity, as things happen.”
He said major fires might happen closer together and weather conditions associated with them could be more extreme – so some years could be much more rainy, while others will be much more dry.
“We watch the drought conditions and the level of water that’s in the forest,” Olsen said.
“Once that level of water starts to take itself out of the environment, and more and more fuel is exposed, that’s a really prime indication that we’re going to be moving back into the potential for serious fire seasons.”