With wildfires raging across Canada, some of the strategy and jargon discussed at briefings and on the news can be a mystery to people. Firefighters in different communities sometimes use different terminology for the same phenomenon, which complicates things.
The Canadian Interagency Forest Fire Center (CIFFC), which helps provinces and territories share firefighting resources, has long maintained a comprehensive glossary of wildfire terminology that helps to ensure that everyone speaks the same language. It’s essential when firefighters move between counties — and even between countries — to fight flames. Several counties also have glossaries online, including British Columbia And Nova Scotia.
“Anytime you have a specialized discipline, it’s important that you agree on the terminology,” said David Martell, a professor emeritus at the University of Toronto who specializes in wildfire control systems.
We consulted guidebooks and wildfire experts to compile a list of the most unique and common terms you may hear during wildfire season.
Bird dog aircraft
A bird dog plays a vital role in aerial firefighting. This aircraft carries the air raid officer, the person responsible for directing all aerial operations during a wildfire. The bird dog flies above the tanker plane and directs them where to dump water to make sure they hit the best spot. Manitoba recently sent a bird dog plane and an air raid officer to fight fires in Alberta, among other places.
Canadian Wildfire Hazard Classification System
The CFFDRS is a national system that assesses the risk of forest fires in a given area. It was established in 1968, but some of its origins date back to the 1920s. You may recognize it from visiting a wooded area.
The signs are easy to understand and they are the most useful indicator of fire risk for most people, Martell said. And while it seems simple, a lot of information goes into determining fire risk, including weather, wind speed, dryness of potential fuel in a forest (such as dead pine needles), topography, how fast a fire would spread, and much more more. .
crossing
This term popped up this week at fire briefings in Nova Scotia, and it’s a dangerous term in the firefighting world. It is an indication of extreme fire conditions.
“Normally the humidity is higher than the temperature, but when the humidity is lower than the temperature, you have something called a crossover,” Martell said. “On a day like that you get fire problems.”
Given the environmental conditions, firefighters say residents of the Upper Tantallon evacuation zone should not expect to return home on Wednesday.
Crown fire
This does not refer to a fire on Kroonland. Rather, it’s a fire that spreads from the forest floor to the crowns (or tops) of trees, said Michael Flannigan, a professor of wildfires at Thompson Rivers University in Kamloops, BC. A fire can spread quickly from treetop to treetop, feeding on branches, twigs and pine cones.
Fire watch
This is an important way to stop or slow down a fire – it’s when crews break through a strategic barrier by clearing trees and shrubs, depriving a fire of even more fuel. This is where the bulldozer boss to work. While that may sound like a reference to Fraggle Rock, the bulldozers in this case are actually destroyers rather than builders. The bulldozer boss is supervising the bulldozers working to clear an area to make sure the fire watch built efficiently and effectively. Fire screens can also be natural barriers to fire, such as roads.
Fire whirls and fires
Fire swirls are spinning columns of hot air, flames and gases that can help expand the perimeter of a fire. They can let go brand — flaming or smoldering embers propelling the wind.
They can be less than a meter to several hundred meters in diameter, when they are often called fire tornadoes. They can cover the entire fire area or just hot spots inside or outside the fire perimeter.
Two wildfires covering more than 7,000 acres of land have forced more than 15,000 people to leave their homes in Nova Scotia. Andrew Chang talks to Environment Canada’s David Phillips about how the fires got out of control so quickly and how this could be just the start of a challenging season.
Line of fire
This is a commonly used term and you may have heard of it. It refers to the place where crews and equipment are actively fighting a fire, according to the CIFCC glossary. Firefighters can get to work line of fire with shovels and other hand tools for 14 straight hours in scorching heat.

Fire outline
This refers to how big a wildfire is – its outer boundary or edge. In Canada, it is usually measured in kilometers. The fire front is the strip of flame at the active edge of the fire. It can be difficult to imagine the size of a wildfire since they are often measured in the unknown area unit of acres.
“What does it mean? What is an acre?” said Flannigan. “I say, ‘Well, it’s about the size of a football field.’
The fire near Halifax is about 950 acres in size. That’s a lot of football fields.
Ground fire
Ground fires can be fueled by tree roots, peat, rotting wood known as burial punk wood And stupid, the layer of decomposing organic matter. All of these are collectively known as ground fuel.
“Certainly in a dry year, roots can be particularly flammable,” says Marieke deRoos of CIFFC. “If there hasn’t been much rainfall and the first few inches underground are dry, unbeknownst to those above ground, the fire can spread underground.”
This is where firefighters’ hand tools often come into play. They use axes, shovels and Pulaskis – which have an ax at one end and an axe, or curved blade, at the other, to break up duff and packed dirt.
National preparedness level
The NPL is a five-level scale used by the firefighting community to describe firefighting equipment needs. According to deRoos, it includes current availability and demand for firefighters or equipment, environmental conditions, the potential for new fires and active wildfires.
Government officials from Emergency Preparedness Secretary Bill Blair to Alberta Premier Danielle Smith are calling this wildfire season “unprecedented.” Andrew Chang explains why they are right.
Level 1 is the least severe; Level 5 is the most severe. Canada is currently at Level 5meaning the continued demand for firefighting equipment is “extreme” and includes international resources such as firefighters from the United States and Australia.
“Nationally, the number of fires is well above the average for this time of year and nearly 12 times the average for area burned for this time of year,” the latest news report said. national wildfire situation report released by Natural Resources Canada says.