Fire Weather Index showed CFB Wainwright primed for wildfire

While investigators from the Canadian Armed Forces comb for clues in the wake of the devastating CFB Wainwright fire that claimed the lives of four soldiers Oct. 17, Kent Moore is taking a sober look at the science — and the signs.

An atmospheric physics professor at the University of Toronto, Moore said the forecast and the Fire Weather Index provide clues that military training planners shouldn’t overlook.

He’s been studying the regional charts and graphs of weather leading up to the tragedy, and wind speed and “fuel” left Wainwright primed for the blaze that left 13 soldiers in critical condition, and injured 26 more, he said.

The Fire Weather Index is a number that figures in a combination of winds, temperature, soil, moisture. High number, high risk.

“It gives you a measure of how how prone an area is to fire, and the Fire Weather Index for Wainwright on Saturday was really high, so the conditions were set,” Moore said.

“The conditions were primed for a fire … I don’t want to say it was forecastable, but unfortunately, the conditions were ripe for a wildfire, so I think they probably should have maybe taken some extra precautions, given the conditions,” he said.

Albertans remember images of flames and smoke billowing in the forest setting of Jasper, but it’s easy to forget grass fires are another, faster kind of wildfire for one reason: tinder burns faster than a log.

“A grass fire is essentially burning kindling or tinder, and so that’s what sort of allowed the grass fire to amplify,” he said.

“It had been a pretty good summer, so the grass was quite high, and it was starting to die off. So essentially, we had these conditions where there was a lot of fuel around, dead or dying grass.”

The fire started on the base during “high-intensity combat training with live munitions,” Maj.-Gen. Wade Rutland, commander of the 1st Canadian Division battalion, told reporters in a Sunday briefing the day after the fire.

The exercise for the Third Battalion Princess Patricia’s Canadian Light Infantry (PPCLI) was meant to prepare them to become a global response task force, ready to move within hours to any hotspot around the world.

“They were throwing hand grenades on a hand grenade range and conducting what we call a section attack — 10 soldiers attacking a simulated enemy,” he said, not speculating about the specific cause of the fire.

“There was a multitude of ordnance moving through the Wainwright training area — grenade launcher, grenades, small arms, ammunition. Quite frankly, it could have been any of that or none of it. When this happens, we send a team in to look at the oil and gas infrastructure to make sure it’s not damaged. Initial impression is not, but we will definitely check. And again, this is why we’re getting that fire marshal team on the ground because we’ve got to check what’s caused it. But it could be a multitude of things,” Rutland said.

The fire had been burning for hours before it took a sudden turn towards the victims, the major-general said.

“The range control knew there was a fire for several hours. It was decided that that could carry on for a certain amount of time, as it was contained,” he said.

The cold fronts that produce gusty winds are relatively easy to forecast, Moore said.

“They don’t get them exactly right, but the weather models do capture them. I think there was probably pretty good warning that there was going to be gusty conditions that afternoon,” he said.

Saturday afternoon, a forecasted cold front came through. Accompanying winds gusted upwards of 80 kilometers an hour around 4 p.m. local time.

“The weather for the majority of the day was well within standard procedures, well below 50 (km/h),” Rutland said Sunday.

The commander on the ground during the tragedy told Rutland the fire was a kilometre away from the victims when it seemed to take on velocity.

“He said within 30 seconds to a minute they saw no fire, and then there was a fire right on top of them,” Rutland recalled.

While it’s surprising to think a fire smouldering a kilometre away can be bearing down on top of you within a minute, it’s absolutely true — because of wind, Kent Moore said.

If a gust of wind is blowing 80 km an hour, an ember borne on it can travel a kilometre in a minute.

Moore cited recent examples of grass fires that took people by surprise.

The town of Lahaina, Hawaii, a few years ago, was gutted by a grass fire that started really small.

Wind was also a key factor to rapidly spreading summer wildfires in the Okanagan.

“Grass fires can move quite quickly, much quicker than a fire in a boreal forest,” he said.

The wind supplies more oxygen to the fire, which allows it to burn, and to propagate.

“Very strong winds led to the fire rapidly moving and also growing in size,” he said.

“I think people were assuming that that kilometre was enough of a buffer to keep the troops safe, but the thing with grass fires is that they can move really, really quickly, and that’s behavior which is a little bit different from what you would find in a forest fire.”

Change in climate can have summers stretching longer and falls get warmer. Moore said planners would do well to consult the Fire Weather Index and cold fronts bearing gusting winds, and also redirect efforts to putting out any smouldering blazes instead of continuing to work nearby.

“Had it been maybe 30-40 years ago, it probably would have been a bit colder, and maybe even some snow had would have fallen recently, so there would be some more soil moisture,” Moore said.

“My heart just goes out to the troops — it must have been horrible to be in that situation,” he said.

Bookmark our website and support our journalism:Don’t miss the news you need to know — add EdmontonJournal.com and EdmontonSun.com to your bookmarks and sign up for our newsletters here.

You can also support our journalism by becoming a digital subscriber. Subscribers gain unlimited access to The Edmonton Journal, Edmonton Sun, National Post and 13 other Canadian news sites. Support us by subscribing today: The Edmonton Journal | The Edmonton Sun.