A wildfire ignited by a lightning strike continued to burn Tuesday in Yellowstone National Park, though an approaching storm front could provide much-needed moisture to knock it down.

Fire bosses continued to estimate the size of the Arnica Fire at 9,300 acres, the same as Monday's acreage. An approaching low-pressure system was boosting winds in the park Tuesday afternoon, and by nightfall the front was expected to produce scattered showers and isolated thunderstorms until midnight, when dropping temperatures could lead to snow showers, park officials said. Seasonal temperatures that dip below freezing at night have produced an odd setting, with icicles forming on trees and buildings from the spray of sprinklers and hoses while flames lick through the lodgepole forest nearby.

The fire, which was reported September 23, continues to hamper traffic in the park. Burning forest along a nearly two-mile stretch of the Grand Loop Road near Yellowstone Lake has closed a section of road between West Thumb and just south of the Lake developed area. At the same time, road construction has closed the loop road between Madison Junction and Norris. However, visitors could still reach Lake from the north via Tower, and the Old Faithful complex was accessible via the park's South and West entrances.

Two-hundred-thirty firefighters were on the fire lines, with overhead assistance from water-toting helicopters that have been targeting spot fires near the Bridge Bay marina, according to a park release. On the ground, firefighters have been using sprinkler systems, hose lines, and fire engines to protect housing, lodgings, and other structures near the fire.