News•May 2, 2013

Drought and Heat May Fuel Early Fire Season in West

Fire season may come early this year in the West, as it has more frequently in recent years, thanks to ongoing drought conditions and increasing temperatures. According to a new outlook issued by the National Interagency Fire Center (NIFC) in Boise, Idaho, major wildfires in California could begin as early as this month, nearly a month ahead of schedule. Wildfire season is also expected to come early in southern Oregon and Washington, as well as in the central Rocky Mountains and parts of the Southwest.

“We’re looking at a combination of low-moisture winter and a warming and drying pattern in the West that will increase the fire potential,” NIFC predictive service manager Ed Delgado told the Associated Press. The West is quickly becoming the epicenter of drought in the U.S., as recent rain and snow has eased severe drought conditions across the Plains and Midwest.

The report, which was released Wednesday, provides a four-month outlook on the potential severity and timing of wildfires across the U.S., and it is based on measurements of temperature, drought, and moisture conditions.

Download Full Report (PDF)

The NIFC expects the worst fire potential to be on the West Coast — in California, Oregon and Washington — which will then spread into Idaho and Montana by July. Most of the fire potential in California will be concentrated in the Sacramento Valley, where a thin winter snowpack and months of drought have increased the amount of dry fuel on the ground to near record levels.

In California, “precipitation pretty much shut off at the beginning of the year,” NIFC wildfire analyst Jeremy Sullens said on a conference call with reporters. “Since they’re not expecting a lot more precipitation for the remainder of the summer, conditions are going to worsen as we go into the hotter part of the year.”

That was evident on Thursday as wildfires, fueled by strong offshore winds, erupted in Southern California, east of Los Angeles. The blaze has already consumed 2,000 acres and is forcing evacuations.

The Southwest is also likely to see some major fires this year, especially in drought-stricken southeastern Arizona and central New Mexico. However, the timing of that risk is expected to vary week-by-week, depending on the amount of rainfall from the Southwest Monsoon, which typically sets in during mid to late-summer. The current dry conditions mean that there is plenty of fuel to burn if a wildfire begins to spread.

Meanwhile, late-season snows across the Rocky Mountains in Wyoming and Colorado have dumped enough moisture to provide an early season buffer against wildfires there. However, in southern Colorado the wildfire risks remain elevated.

Large blazes are becoming more common in the West as average temperatures increase and spring snowmelt occurs earlier in the year. In addition, land-use changes have helped contribute to more wildfires as communities expand into previously unoccupied territory.

Compared to an average year in the 1970s, during the past decade there were seven times more fires greater than 10,000 acres each year, and nearly five times more fires larger than 25,000 acres each year, according to Climate Central research.

The Southeast, parts of which had been stuck in a severe drought for more than two years, is at low risk for wildfires, thanks to months of consistent rains that have lifted the region out of its multi-year drought. While some wildfires have already broken out in Florida this spring, the risk of more fires throughout the year will shrink as the state enters its rainy season in early summer, NIFC said.

The Drought Monitor, as of January 1, 2013 and April 30, 2013. Three months of rain and snow have brought relief to the Southeast and Upper Midwest, but conditions have deteriorated in the West and Southwest.
Credit: U.S. Drought Monitor

The increased risk of wildfires in the West reflects the changing pattern of the national drought, which still engulfs more than 46 percent of the continental U.S. Since January 1, the epicenter of the drought has shifted west as the drought has eased its grip on the heart of the Great Plains in Nebraska and Kansas, and has all but disappeared Georgia and South Carolina. Instead, the drought has intensified in the Southwest and West, so that the most severe drought conditions are now in New Mexico, southern Colorado, and south and west Texas. Drought is also intensifying throughout California, according to the latest national Drought Monitor, which was released on Thursday.

Drought expanded and intensified during the past week all across California, Nevada, Utah, Colorado, and Arizona. A large patch of “exceptional” drought, the worst category, developed in central New Mexico.

Droughts in the Southwest are projected to become more frequent and severe in coming decades due, in large part, to manmade global warming, although the current Southwestern drought has not been directly linked to climate change as of yet.

Some relief was seen in southern and central Texas, where more than 6 inches of rain fell locally during the past week, and led to improvement in all four categories of drought. However, more than 73 percent of the state is still under “severe” drought or worse. Texas has not been completely drought-free since April 2010.

Climate Central's interactive wildfire tracker. You can hover over a given fire to see its name, and if you zoom in you’ll be able to see the outline of the area that’s burning. The data comes from the Geospatial Multi-Agency Coordination Group, and is updated daily.