Perfect weather conditions at the dry end of the season is fueling a rapid expansion of the Arnica Fire, which has grown to 1,600 acres in size and forced a temporary closure of the Grand Loop Road today.

Park Service officials warn that additional road closures may be necessary. Indeed, perfect weather for a fire expansion are on tap for the next two days: the fire has plenty of mature lodgepole pine to work through, and there's no precipitation in the forecast until Tuesday, when there's a 20 percent chance of rain, and Wednesday, when there's a chance of snow.

Despite the proximity to the road, no hiking trails and backcountry campsites in the area have been closed (Bridge Bay Campground had already closed for the season), but boat launches from the Bridge Bay Marina. 

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