BONNERS FERRY — As temperatures have risen, so has fire activity on the Upper Smith Fire.

"Retardant was dropped along Parker Ridge and reinforced with water drops, helping hold the fire at the ridge," Northern Idaho Blue Team members said in an update noting that fire activity was centered in Long Canyon. "Helicopters and airplanes continued water drops throughout the day."

The Upper Smith Fire, located 20 miles northwest of Bonners Ferry in the Kootenai River Valley, has burned 4,220 acres. The six-week-old fire is 38% contained.

There are 139 personnel assigned to the fire, including four hand crews, six engines, four helicopters, two scooper planes and two air tankers. In addition, there are six water tenders, an ambulance and assorted heavy equipment.

Blue Team crews were expected to patrol along control lines, monitoring for potential risks associated with a predicted red flag warning.

Typically issued by the National Weather Service, such warnings indicate weather conditions are present that could lead to dangerous wildfire behavior. Under the warning, which runs through 11 a.m. today, thunderstorms and strong winds are expected, with forecasts calling for gusts of up to 50 mph.

As the need arises, Blue Team officials said additional water drops would be made to help keep the fire in check.

Saturday, fire managers continued to assess the use of retardant in targeted areas on Parker Ridge. Also, masticator crews are working to boost contingency lines along the road system west of the fire perimeter.

On the southern end of the county, the Caribou Fire is 50% contained, with fire and hose lines delivering water completely around the fire.

The fire is burning northwest of Naples near Ruby Creek in steep, rocky terrain that is difficult to access. Estimated at 10 acres, the fire is 50% contained.

The U.S. Forest Service has helped Idaho Department of Lands crews with coordination and support. The Upper Smith incident management team shared assigned aircraft and other resources during the fire's initial attack, IDL officials said.

Located 7 miles north-northeast of Clark Fork, the Porcupine Fire has burned 127 acres. The fire is 0% contained.

"Steep terrain, rolling debris and limited road access continue to influence suppression opportunities," Idaho Panhandle National Forest officials said. "Aside from initial attack … further fireline construction opportunities have not been feasible. Aviation resources continue to be key in keeping the fire in check."

The fire crew's main emphasis continues to be focused on aerial attack and keeping the Porcupine Fire within its current footprint.

Fire danger remains rated as extreme in the region, meaning that fires of all types start quickly and burn intensely, according to local U.S. Forest Service officials.

Stage 2 fire restrictions are in effect in Bonner and Boundary counties, while Stage 1 fire restrictions are in effect in Kootenai, Shoshone and Benewah counties.

Under Stage 1 fire restrictions, campfires and stove use are prohibited except at designated recreation sites, on private property or in approved fire structures. Smoking is limited to enclosed vehicles, buildings or cleared areas free of flammable materials.

Stage 2 fire restrictions prohibit fires and campfires and smoking except within an enclosed vehicle or building, or a designated recreation area that is at least 3 feet in diameter and barren or cleared of flammable materials. In addition, "Hoot Owl" restrictions limit chainsaw and machinery operation from 1 p.m. to 1 a.m.

For more information on fire restrictions, go to bit.ly/45a7eIT.

Information: InciWeb.wildfire.gov.