Behind the scenes: fire weather forecasting



In 2003, Jesse Ellis abandoned his job digging magnetically-tagged stones out of creek beds on the west coast of Vancouver Island to experience one of the busier wildfire seasons in recent history as a casual hire in Barriere, B.C.  Jesse traded clean air, cool water and tranquillity for smoke, dust and the sound of helicopters – and he was happy.

That season, and a subsequent stint on an initial attack crew, changed the trajectory of Ellis’ life as he switched from studying geology to atmospheric science to pursue a career with wildfire. Ellis was hired as a Fire Weather Forecaster in 2009.

As one of four staff weather forecasters working for the Predictive Services Unit of the BC Wildfire Service, Ellis plays a key role behind the scenes. Much of his job comes down to making meteorological data relevant and valuable to BC Wildfire Service staff members. He uses various sources of weather information including satellite imagery, radar, field observations and weather models to give field crews the information they need to plan their work on the fire line. His work also informs other aspects of the BC Wildfire Service, including prevention and preparedness.

Ellis says his time on an initial attack crew helped him become a better forecaster, and emphasized the importance of staying connected with fieldwork in his current position.

“My forecasts improve after I’ve gotten back out into the field to kick the dirt, or get on a drip torch for an afternoon of burning. It helps to remind me what’s important in our work.”

The three most critical weather factors he focuses on during the core fire season are wind, relative humidity and atmospheric stability. All three can be challenging to predict, but each is a strong driver of fire behaviour. In addition, his weather information is used by other members of BC Wildfire Service to predict how much a fire may grow. This can inform potential evacuation orders or warnings for field crews.

During the winter, he supports partner agencies such as the Ministry of Transportation and Infrastructure in their work to predict and manage avalanche risk. During the spring and fall, his focus is on prescribed fire, so he stays operational year-round. Starting months out from the prescribed fire season (spring and fall, when conditions allow), Ellis looks at how the more common synoptic weather patterns will interact with local topography to help zone staff identify ideal burning conditions. One of the critical factors is planning how to minimize smoke in smoke-sensitive areas such as nearby communities and highway corridors. 

Closer to the burn date, Ellis will forecast the weather to run calculations on fuel moisture codes.

“That way, we can determine whether the fuel moisture is likely to come into prescription, which means that it’s within a range that it burns hot enough, but not too hot, to achieve the objectives the zone staff have identified for the burn,” explains Ellis.

Before a prescribed fire, Ellis will provide a spot forecast, which provides field staff with information such as wind speed and direction, relative humidity, temperature and cloud cover.

“It also gives them the confidence that there is not likely to be a weather event that will catch them by surprise or threaten crew safety or the objectives of the burn during or soon after they begin ignitions,” says Ellis.

During wildfires or prescribed fires, Ellis monitors conditions to ensure that the weather is unfolding according to plan, ready to advise field staff if conditions begin to change unexpectedly.

The level of confidence a meteorologist like Ellis has in his forecast can change from one day to the next.  This information is also conveyed to the user to incorporate forecast confidence into their daily plan.  Ellis is not shy to point out the parts of his forecast that are most likely to go wrong (‘bust’ in forecaster terms).

“If I’m off by more than a few percentage points on the relative humidity or by more than four or five kilometres an hour on the wind, I know I need to adjust my forecast process so that I can improve.”

At the end of the day, Ellis said his satisfaction comes from being able to provide accurate and timely information to crews.

“My favourite part of the job is knowing that I’m doing the best I can to help keep our field staff safe while also providing them with the information they need to maximize efficiency in their work.”

To learn more about current fire weather, visit bcwildfire.ca.

To learn more about prescribed fire, visit bcwildfire.ca and prescribedfire.ca.