As Utah’s fire season ramps up, six active wildfires are already burning across the state. The Bonneville Fire has been largely contained, but the Iron and Cottonwood Fires have grown to nearly 37,000 and 60,000 acres, respectively.

Understanding wildfires has been the focus of Philip Dennison’s career. The professor and chair of the University of Utah’s School of Environment, Society & Sustainability is a leading expert in remote sensing and wildfire science. For nearly 30 years, he has used satellite and airborne technologies to study drought, vegetation and wildfires.

As director of the U’s Utah Remote Sensing Applications Lab and member of NASA’s FireSense Implementation Team and the NASA/USGS Landsat Science Team, Dennison develops real-time remote sensing tools to support firefighter operations, assess fire risk and help land managers to better prepare for, respond to and recover from increasingly extreme wildfires.

Below, Dennison addresses Utah’s wildfire outlook, the factors shaping this year’s fire season and how Utahns can reduce fire danger.

Utah is battling several active wildfires, including the Cottonwood, Iron and Bonneville Fires. Do they have anything in common?

The big thing these fires have in common is that drought and high temperatures have made vegetation very susceptible to burning this summer. When combined with high winds and an ignition, fires can grow very rapidly.

Most of the fires we’ve seen so far this year fit a common pattern—human activity causes an ignition in dry grass and under high winds, the fire quickly gets carried by grasses and sagebrush uphill through areas of denser fuels.

It just takes one spark to ignite a wildfire. Sandra Miller, a graduate student in my lab, mapped ignition potential across the state of Utah. In the case of the Bonneville Fire, the hills above campus bring very flammable dry grasses in close proximity to lots of human activities.

How do people accidentally spark a wildfire?

Driving over or mowing dry vegetation, dragging a trailer chain, backyard burning, campfires, fireworks and target shooting are all risky this summer because of drought and especially risky during high winds.

How have drought, temperature and vegetation conditions made Utah vulnerable to wildfire this summer?

It was a dry winter, but there was enough precipitation to promote grass growth. And there’s plenty of dead vegetation from past years of growth that has created lots of fine fuels. Hot temperatures and very low relative humidity have dried these fuels out, making them highly flammable. In periods of higher winds, a small fire start can quickly spread out of control.

How does this year compare with previous Utah fire seasons?

Fire season in northern Utah starts at a lower elevation. Some of Utah’s biggest lower-elevation fires have occurred in late June and early July. These fires have followed warm, dry springs and happened during periods of higher winds. The 2007 Neola North Fire and 2012 Clay Springs and Wood Hollow Fires all fit this pattern. The largest fire in Utah history, the 2007 Milford Flat Fire, was in early July. This year’s fires started a little earlier in June than we’ve seen in past years.

The Cottonwood Fire in Fishlake National Forest is Utah’s first big forest fire this season. There’s precedent for that timing, too. The Seeley Fire burned 48,000 acres in the Manti-La Sal National Forest under very dry conditions in late June 2012.

2007 and 2012 continued on to be bad fire years through the rest of the summer, and it’s likely we’ll see the same this year.

What is the wildfire outlook in Utah and the West this summer?

The outlook is pretty grim. Low precipitation this past winter, combined with hotter temperatures this spring and summer are setting the stage for a difficult fire season across the West. We’re only just getting started, especially at higher elevations where fuels haven’t dried out yet in many areas.

Is there any part of Utah that you’re particularly concerned about this season?

Fire danger will be high across the entire state this summer. Fire season is just getting started, and unless we get lucky with some monsoon rains later this summer, we’ll see high fire danger all the way into early fall. I’m most worried about higher elevation forests this summer. With low snowpack this past winter, the potential for large forest fires will be high.

All areas of the foothills along the Wasatch Front have elevated fire risk, and people need to keep in mind that what happened above campus this time could happen in Emigration Canyon, the Upper Avenues or at the mouth of the Cottonwood Canyons in the future.

What steps can be taken to reduce Utah’s wildfire risk?

The most important thing we can do is reduce ignitions. A majority of Utah’s fires are caused by human ignitions. Beyond that, the Bonneville Fire scar can be reseeded to reduce invasion by more fire-prone grasses like cheatgrass.

Header image: A firefighting plane drops flame retardant on the Cottonwood Fire in Fishlake National Forest. Credit: USFS/Fishlake National Forest