The National Weather Service’s active red flag warning count climbed to 37 Saturday, up from 26 a day earlier, as critical fire weather conditions spread across a wide stretch of Montana and persisted over the Sierra Front and the Pacific Northwest.
The geographic footprint shifted overnight. Arizona has dropped off the list of affected states, while South Dakota is now included, leaving eight states under some form of red flag warning: California, Colorado, Idaho, Montana, Nevada, Oregon, South Dakota and Washington. The biggest change is in Montana, where the National Weather Service office in Glasgow canceled an earlier warning and then issued a new one covering a broad band of counties from the Northern Valley and Northern Phillips Counties through the Little Rockies and the Lower Missouri River Breaks, including the Charles M Russell National Wildlife Refuge. Further south, warnings now stretch across Wheatland, Sweet Grass, Stillwater, Golden Valley, Musselshell, Yellowstone, Rosebud, Treasure and Custer counties, plus the Gallatin, Custer and Bighorn national forests and the Crow and Northern Cheyenne reservations — a much larger and more fragmented set of zones than the state carried Friday.
In that new Montana warning, south-southwest winds of 10 to 15 mph with gusts to 25 mph are expected this afternoon and evening, with relative humidity dropping as low as 13 percent. The National Weather Service says any fires that ignite under those conditions can spread rapidly.
Elsewhere, the pattern is holding rather than easing. An upper-level low moving into the Pacific Northwest is keeping wind and humidity at critical levels through the Cascade Gaps and central Oregon, with warnings covering Kittitas Valley, the Lower Columbia Basin, the Central and Southern Blue Mountains, the Northern Deschutes National Forest and the Central Mountains of Oregon into Saturday evening; winds there are running 10 to 20 mph with higher gusts. The Sierra Front corridor along the California-Nevada line — including Carson City, Douglas, Storey, Washoe and Lyon counties, Surprise Valley and eastern Lassen County — remains under warning for a second straight day.
The National Weather Service is asking residents and fire crews in all affected zones to avoid activities that could spark a fire, including outdoor burning and equipment use that throws sparks, until warnings are lifted. With humidity in the teens and gusty winds forecast across both the Northern Rockies and the Northwest through the weekend, fire officials say the risk of fast-moving fires remains elevated across the region.