Whitefish Mountain Resort Snow Report

013 FXUS65 KMSO 211913 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 113 PM MDT Fri Aug 21 2026 .DISCUSSION... KEY MESSAGES: - Marginal risk (5% chance for any given location) for severe thunderstorms capable of severe wind gusts (60 mph) on Saturday areawide. - Fire Weather Watches in effect Saturday into early Sunday morning across northwest Montana for dry lightning capable of new fire starts. - Fire Weather Watches in effect Sunday across southwest Montana (Fire Zones 110-111) for dry and windy conditions. A ridge of high pressure continues to bring hot and dry conditions to the area, with high temperature running 10-15F above normal today. Water vapor satellite imagery shows monsoon moisture streaming northward across the Great Basin into the Northern Rockies, with mid-high level cloud cover beginning to increase. High-resolution models and forecast soundings suggest atmospheric instability will begin to support high-based shower and isolated thunderstorm activity by this evening across central Idaho. Convection will move northward overnight, reaching western Montana after midnight. Little to any precipitation is expected as warm and dry air is present in the low levels. Isolated lightning activity (5-10% probability) can not be ruled out across north- central Idaho and southwest Montana this evening through early Saturday morning as this wave of showers and isolated convection moves northward. The risk for strong to isolated (5% probability) severe thunderstorms enters the picture Saturday afternoon and evening, with strong to damaging winds being the primary threat. An upper- level trough is still on track to lift out of the Pacific Northwest and phase with increasing monsoonal moisture providing plenty of moisture, lift, and instability for thunderstorm development. Widespread shower and thunderstorm activity will increase through the afternoon and evening hours across the region. A fire weather watch has been issued across the West Lolo and Kootenai National Forests and the Flathead Reservation as thunderstorms will bring an increased risk for dry lightning capable of starting new wildfires. PWATS are forecast to near and exceed 1.0 inches in southwest Montana and Lemhi County on Saturday, leading to a marginal threat for excessive rainfall, due to intense precipitation rates. Normally vulnerable spots such as burn scars, and areas of steep, rocky terrain will be monitored closely for excessive rainfall leading to debris flows and/or rock slides. A cold front crosses through, from the west, Saturday evening into Sunday lowering daytime high temperatures by 10-15 degrees; closer to seasonal normals. However, the post-frontal environment will also bring deep mixing, strong westerly winds, and a very dry airmass creating elevated to near-critical fire weather conditions especially considering the preceding risk of new lightning starts and holdovers from Friday and Saturday`s convection. A fire weather watch has been issued for Sunday across southwest Montana (Fire Weather Zones 110-111), where confidence is increasing for windy and dry conditions to bring critical fire weather. Ensemble model cluster analysis shows modest-high confidence (>80% agreement) for the Northern Rockies to be under the influence of southwesterly flow Monday through Wednesday next week. Model guidance suggests a ridge of high pressure centered over the Rockies, with a trough of low pressure near the Pacific Northwest coast. This pattern suggests mainly dry and warm conditions, with chances for showers and thunderstorms focused across Lemhi County, ID into southwest Montana. && .AVIATION...High pressure continues to bring hot conditions and elevated density altitudes across the regional airspace this afternoon. GOES Water Vapor imagery shows monsoon moisture moving into the mid-upper levels of the atmosphere south to north today. Elevated convection developing around and after 22/0000Z near KSMN and KBTM will spread northward into the overnight bringing the risks of localized erratic outflow wind gusts of 20-30 knots, inducing low-level turbulence, and LLWS near these high-based storm cores. Widespread shower and thunderstorm activity on Saturday poses threats for strong to severe wind gusts, hail, and temporary MVFR/IFR weather conditions across the region particularly during the afternoon hours. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Fire Weather Watch from Saturday afternoon through Sunday morning for Flathead Reservation...Kootenai...West Lolo. Fire Weather Watch from Sunday afternoon through Sunday evening for Deerlodge/West Beaverhead...East Beaverhead. ID...Heat Advisory until 8 PM PDT this evening for Lower Hells Canyon/Salmon River Region...Orofino/Grangeville Region. && $$