BECKWOURTH, Calif. (AP) -- A California wildfire that closed nearly 200 square miles of forest forced evacuations across state lines into Nevada on Friday as winds and scorching, dry weather drove flames forward through trees and brush.
The Beckwourth Complex -- which began as two lightning-caused fires in Plumas National Forest -- showed "extreme behavior," fire information officer Lisa Cox said Friday evening.
Hot rising air formed a gigantic, smoky pyrocumulus cloud that reached thousands of feet high and created its own lightning, Cox said.
Spot fires caused by embers leapt up to a mile (1.6 kilometers) ahead of the northeastern flank -- too far for firefighters to safely battle, Cox said.
Winds up to about 20 mph (32 kph) on ridgetops were funneling flames up draws and canyons full of dry fuel, where "it can actually pick up speed," Cox said.
By evening, the fire was approaching U.S. 395, a main interstate in the northern Sierra Nevada not far from the border. Although the flames hadn't crossed that divide, the Washoe County Sheriff's Office told people to evacuate some areas in the rural communities of Ranch Haven and Flanagan Flats, north of Reno.
"Evacuate now," a Sheriff's office tweet said.
Although there are no confirmed reports of building damage, the fire already prompted evacuation orders or warnings for hundreds of homes and several campgrounds in California along with the closure of nearly 200 square miles of Plumas National Forest.
The blaze, which was only 11% contained, officially had blackened more than 38 square miles (98 square kilometers) but that figure was expected to increase dramatically when fire officials were able to make better observations.
Nearly 1,000 firefighters were aided by aircraft but the blaze was expected to continue leaping through trees and chaparral that already are bone-dry because of low humidity and a heat wave forecasted to continue through the weekend.
"We're expecting more of the same the day after and the day after and the day after," Cox said.
The air was so dry that some of the water dropped by aircraft evaporated before it reached the ground, she said.
The fire was one of several burning in the West, including several that destroyed dozens of California homes in recent days.
In the region between the Oregon border and the northern end of the Central Valley, the big Lava and Tennant fires were significantly contained, and progress was reported at the Salt Fire as containment improved to 45%. The Salt Fire has burned 27 homes and 14 outbuildings north of Redding, which hit 100 degrees (37.7 Celsius) before 11 a.m. The Lava Fire destroyed 20 structures, including 13 homes, and damaged two structures. The Tennant Fire destroyed five buildings, including two homes.
In north-central Arizona, increased humidity slowed a big wildfire that posed a threat to the rural community of Crown King. The 24.5-square-mile (63.5-square-kilometer) lightning-caused fire in Yavapai County was 29% contained. Recent rains allowed five national forests and state land managers to lift public-access closures.
Climate change is considered a "key driver" of a trend that is creating "longer and more intense dry seasons that increase moisture stress on vegetation and make forests more susceptible to severe wildfire," the California Department of Forestry and Fire Protection said recently.
Fire crew officials will be briefing the community on progress Friday evening at the Chiloquin Community Center. The meeting will be streamed on the Facebook page for the Fremont-Winema National Forest beginning at 7 p.m.
In Oregon, pushed by strong winds, a wildfire in Klamath County grew from nearly 26 square miles (67 square kilometers) Thursday to nearly 61 square miles (158 square kilometers) on Friday in the Fremont-Winema National Forest and on private land. It was 0% contained, according to a Facebook post by the incident management team. Klamath County Emergency Management on Friday issued an immediate evacuation order for people in certain areas north of Beatty and near Sprague River. California dispatched two strike teams with wildland engines to help.
In Idaho, Gov. Brad Little declared a wildfire emergency Friday and mobilized the state's National Guard to help fight fires sparked after lightning storms swept across the drought-stricken region.
Fire crews in north-central Idaho were facing extreme conditions and gusts as they fought two wildfires covering a combined 19.5 square miles (50.5 square kilometers). The blazes threatened homes and forced evacuations in the tiny, remote community of Dixie about 40 miles (64 kilometers) southeast of Grangeville. Efforts were complicated in part because resources were stretched thin, fire managers said, and the area has very challenging terrain covered with parched trees and plants.
Meanwhile, forecasters warned that much of California will see dangerously hot weekend weather, with highs in triple digits in the Central Valley, mountains, deserts and other inland areas because of strengthening high pressure over the state. Heat warnings did not include major coastal populations.
On Friday, Death Valley National Park recorded a staggering 130 degrees Fahrenheit (54.4 Celsius).
If verified, it would be the hottest high recorded there since July 1913, when the same Furnace Creek area hit 134 degrees Fahrenheit (56.6 degrees Celsius), considered the highest reliably measured temperature on Earth.
California's power grid operator issued a statewide Flex Alert from 4 p.m. to 9 p.m. Friday to avoid disruptions and rolling blackouts. Flex Alerts call for consumers to voluntarily conserve electricity by reducing the use of appliances and keeping the thermostat higher during evening hours when solar energy is diminished or no longer available.
Gov. Gavin Newsom on Friday signed an emergency proclamation suspending certain requirements so the state could obtain additional power capacity.