MONTANA — Montana is headed into an unsettled and generally cool final week of October. After a mostly quiet Sunday, rain and mountain snow will expand across the state Monday night into Tuesday, followed by a brief lull Wednesday before additional rounds of precipitation return late in the week.
SUNDAY NIGHT
Late Sunday into Sunday night, some light rain will develop across far southeast and northeast Montana, especially near the Dakota border and along the Yellowstone River from Terry toward Sidney.
MONDAY
Monday begins relatively quiet for much of the state, although patchy fog or low clouds could redevelop in portions of southwest Montana and along some south-central Montana foothills. Gusty southeast winds develop across northeast Montana. Light rain may linger near the Dakota border, while western and central portions of Montana remain mainly dry through much of the day.
MONDAY NIGHT
A stronger Pacific system begins moving into the state. Rain and mountain snow spread into western and southwest Montana Monday afternoon and evening before expanding eastward overnight. Snow levels in western Montana fall toward 4,000 to 5,000 feet, while accumulating snow becomes increasingly likely across the Madison and Gallatin Mountains and other higher terrain.
TUESDAY
Tuesday looks like the most active statewide weather day early in the week. Periods of rain spread across the lower elevations with accumulating snow in the mountains and at some higher passes. Southwest Montana has a 40 to 80 percent chance of receiving at least a quarter-inch of liquid precipitation, while higher peaks of the Madison and Gallatin Mountains have a 50 to 80 percent chance of at least four inches of snow. Western Montana can expect snow levels generally around 4,000 to 5,000 feet. South-central and southeast Montana also see rain and mountain snow, with several inches possible over portions of the Beartooth, Absaroka and Crazy Mountains. Northeast Montana sees increasingly widespread rainfall as the system crosses the region.
WEDNESDAY
Conditions should improve somewhat Wednesday across central and southwest Montana as a temporary ridge moves through, bringing a period of mostly dry weather. Western Montana remains within a broader unsettled pattern, while rain from Tuesday's system may linger into Wednesday across northeast Montana. South-central and southeast Montana currently appear relatively quiet, with daytime temperatures still generally in the 40s and 50s.
THURSDAY THROUGH SATURDAY
The break will not last long. Another trough is expected to move into Montana late in the week, bringing additional rounds of rain and mountain snow from west to east. Western Montana should remain cooler than normal with periodic precipitation and mountain snow, while north-central and southwest Montana also turn cooler and wetter again. South-central, southeast and northeast Montana remain in an unsettled southwest-flow pattern with occasional precipitation possible into the weekend. Forecast confidence decreases regarding the timing and track of individual late-week systems, but the overall pattern favors continued cool and unsettled weather across Montana.
