BOISE, Idaho — Wildfire risk will be above average in much of the West, according to the National Interagency Fire Center’s new forecast.
July marks the start of the primary wildfire season in the Northwest, Intermountain West and the Northern Great Basin.
Bryan Henry, fire weather program manager at the Boise-based center, said in an interview that an unusually wet June — precipitation was 200-400% of average across most of Idaho except in the northern panhandle — “will delay the onset of more significant fire activity until mid- to late July.”
Idaho’s central mountains, where snowpack and runoff have been well below average, could see some small fires by around July 10, a few days later than usual after some rain in late June, he said.
Henry said Northeastern Washington, the Northern Idaho panhandle and Northwestern Montana, precipitation was 50-75% of normal in the second half of June, so “a normal July is expected as the preexisting conditions continue.”
“Areas of emerging concern are Northern California, Northwest Nevada and Southern through Central Oregon,” he said. “Precipitation received over the last month in these areas has been generally below 50% of average, and in some cases less than 5% of average.”
That was the case in the San Francisco Bay Area.
Temperatures across most of the West have been about 2 degrees above average over the past two months, Henry said.
In his forecast for July through October, he said the potential for significant large fires, burning total acres exceeding long-term medians, is above normal in the Northwest, Northern California, Hawaii and the Northern Great Basin. It’s normal in the Northern Rockies, Alaska and Southern California.
The Northwest’s cool, wet weather in June delayed some fuel curing, but will be followed by conditions that are warmer and drier than average through September — increasing the risk of large fires, particularly in Central Oregon and Central Washington, Henry wrote.
Conditions expected to be warmer and drier than normal should elevate fire risk in Northern California and Hawaii, he wrote. Dead fuels at all elevations are expected to be dry enough to carry fire.
Fine-fuel loading was 100-300% of normal across parts of Nevada, Arizona, Utah and Southern Idaho as July began, and patchier in parts of Southern Utah and Idaho.
The chance of thunderstorms will increase through July in the Northern Great Basin, with some periods of gusty winds, precipitation and lower temperatures as low pressure continues to track, Henry wrote. This will prevent much of Idaho from being critically dry during much of July.