The National Weather Service in Honolulu has issued a red flag warning for leeward areas of all islands Sunday as weather conditions become favorable for wildfires.

“The combination of dry fuels, strong and gusty trade winds and low relative humidity levels could produce extreme fire behavior on Sunday, especially during the afternoon hours,” the warning says. “Any fires that develop will likely spread rapidly and be difficult to control.”

Outdoor burning is not recommended, forecasters said.

The warning is in effect from 6 a.m. to 6 p.m. Sunday, and replaces an earlier fire weather watch.

Forecasters said east to northeast winds will be 15 to 30 mph with gusts up to 50 mph, and humidity will be low at 40 to 45%. Sunday’s high temperature for Honolulu is forecast to be 88 degrees.

The weather service has also issued a wind advisory for portions of all islands but Niihau for Sunday.

“Winds will accelerate downslope, near mountain tops and ridges, through gaps in the terrain, and in areas typically exposed to the tradewinds,” says the advisory, which is also in effect from 6 a.m. to 6 p.m.

Strong winds “can tear off shingles, knock down tree branches, blow away tents and awnings and make it difficult to steer, especially for drivers of high-profile vehicles,” forecasters said. “Watch out for falling tree branches when walking or driving. Make sure tents and awnings are secure or take them down. Be prepared for power outages.”