A Winter Weather Advisory issued by the National Weather Service in Great Falls is in effect from midnight Saturday night through midnight Sunday night, covering the Big Belt, Bridger, Castle, Little Belt, and Highwood Mountains — the ranges that frame the valley east and south of Helena.

Forecasters are calling for total snow accumulations of 3 to 8 inches across the affected ranges, with isolated spots on the northern slopes of the Little Belt Mountains potentially seeing up to a foot. Wind gusts up to 40 mph will compound conditions, making visibility and traction on backcountry roads a serious concern.

The advisory lands in mid-May, later in the season than most Helena residents expect to be watching mountain snow forecasts. But the ranges covered — including the Big Belts directly east of town and the Highwoods north toward Great Falls — are popular destinations for spring hiking, fishing access, and weekend driving on roads that may not be fully maintained at this point in the year.

Anyone planning to head into those mountains this weekend should expect conditions to change quickly and check road conditions before departing. The NWS advisory warns specifically of slippery backcountry roads as the primary impact.