Red-flag warning issued for wildfire threat on Long Island

A red flag warning is in effect Wednesday from 10 a.m. to 8 p.m., signaling "an enhanced threat for the spread of wildfires."

Relative humidity is expected to be as low as 20 percent, and 15 to 25 mph winds are forecast, with gusts up to 35 mph, according to the National Weather Service, which issued the warning.

This means that conditions are such that if fires start, they "may spread rapidly and become difficult to extinguish," the service said. The biggest threat is expected in the afternoon, when winds will be strongest and humidity lowest, the service said.

Low humidity levels are drying out potential "fuel," such as dead leaves and grasses, pine needles, small branches, and the wind would help spread a fire, were one to start, said Tim Morrin, weather service meteorologist in Upton.

Brush fires are of special concern in the weeks leading up to "green up," when new, live leaves arrive, he said.