


Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
282 FXUS65 KMSO 162004 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 204 PM MDT Thu Oct 16 2025 .DISCUSSION... KEY MESSAGES: - Scattered showers and gusty winds return on Friday afternoon/evening - Minor travel impacts are possible over mountain passes Sunday night/Monday due to snowfall Persistent stratus across western MT and north-central ID is slowly eroding this afternoon due to mid-level dry air entrainment and increasing winds aloft. Stratus is expected to lift and dissipate for most areas through this evening, though locations nearest the Continental Divide and northwest Montana will be the last to clear, and may not fully do so until tomorrow. On Friday, a fast-moving clipper like system will traverse the region. The primary impact will be gusty winds, which will also mix out any lingering stratus. Probabilities for gusts reaching 30 mph are 40-60% for the higher terrain and valleys of western MT. A lower probability (20-30%) exists for gusts exceeding 40 mph, mainly along the Continental Divide into southwest MT. Anticipate choppy conditions on area lakes. Showers will primarily be limited to the higher terrain, with snow levels remaining above 5500 feet, resulting in minor accumulations only in the high backcountry. A shortwave ridge will provide a period of dry and pleasant fall weather on Saturday. However, the pattern becomes active again on Sunday. The next system, a cold front associated with remnants of an atmospheric river, will arrive late Sunday morning and afternoon, bringing widespread showers and gusty winds. Snow levels will fall significantly, starting near 7000 feet on Sunday and dropping to 4500-5000 feet by Sunday night. The primary impact will be accumulating snow for mountain passes Sunday night into Monday morning, enhanced by lingering showery, upslope flow. Current mean forecast snow totals are 2-4 inches for Lolo, Lookout, Lost Trail, and Marias passes, with 4-8 inches in the higher terrain. This will create cold, snowy, and hazardous conditions for backcountry users. While valleys may see snow mix with rain by Monday morning, no valley accumulation is expected. && .AVIATION...Prevailing low stratus has begun to erode under increasingly dry northerly winds aloft. Mountain obscurations are still possible through the evening due to the broken cloud deck. If complete clearing occurs across the region before sunset, low stratus into Friday morning will be much less likely. If a broken low cloud deck remains below mountain ridgelines through sunset, there is the potential for localized lowering ceilings or valley fog into the morning. Highest chances for continued fog or stratus will be across southwest Montana and the Continental Divide. Widespread west winds gusting up to 25 knots will begin to further scour out low level clouds in most locations by 17/1800z. There is a low (~20%) chance of 35 knot gusts or more especially near any stronger shower or storm outflow. Chances for showers and an isolated thunderstorm between 17/1800z and 18/0600z under west-northwesterly flow could cause brief deterioration in flying conditions, and lowered ceilings. Clearing and drying expected into Saturday with the potential for some morning valley fog or low stratus. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$