FNUS55 KMSO 200751 FWFMSO Fire Weather Planning Forecast for Wrn Montana and N Cntrl Idaho National Weather Service Missoula MT 151 AM MDT Wed May 20 2026 .DISCUSSION... Idaho (Zones 102 and 103): Scattered showers and isolated thunderstorms are possible today, a wetting rain is low probability except along the Bitterroot Crest. A warming and drying trend begins Thursday. Northwest MT (Zones 104 and 105): Widespread showers and scattered thunderstorms will be possible today, with a 50% chance of a wetting rain, mainly US-93 and east to the Continental Divide. A warming and drying trend begins Thursday. West Central MT (Zones 106, 107 and 108): Widespread showers and scattered thunderstorms will be possible today, with a 50 to 80% chance of a wetting rain, mainly US-93 and east to the Continental Divide. A warming and drying trend begins Thursday. Southwest MT (Zones 109, 110 and 111): Widespread showers and scattered thunderstorms will be possible today, with a 50 to 80% chance of a wetting rain. A warming and drying trend begins Thursday. IDZ102-103-210800- Palouse/Hells Canyon-Clearwater/Nez Perce- 1251 AM PDT Wed May 20 2026 .TODAY... * Sky/Weather.........Partly cloudy. Slight chance of thunderstorms in the afternoon. Snow level 7500 feet. * Max Temperature.....63-73 valleys and 50-60 ridges. * Min Humidity........35-45 percent valleys and 48-58 percent ridges. * 20-Foot Winds....... * Lower Elevation......West 5-15 mph. * Ridge Top............West 5-10 mph becoming northwest 10-20 mph in the afternoon. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 6 kft agl after 1500. * Transport Winds.....Variable less than 10 mph until 1000. Northwest 15 mph after 1500. * Chance Lightning....Near 0 percent over the Palouse/Hells Canyon...and 30 percent toward the Clearwater/Nez Perce. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. Chance of rain showers and slight chance of thunderstorms. Snow level 7000 feet. * Min Temperature.....33-43. * Max Humidity........73-83 percent. * 20-Foot Winds....... * Lower Elevation......Northwest 5-10 mph in the evening becoming downslope/downvalley 2-5 mph. * Ridge Top............Northwest 10-20 mph becoming north 5-10 mph after midnight. * Mixing Height.......5 kft agl until 2000. Below 500 ft to 1 kft agl after 2100. * Transport Winds.....Northwest 15 mph until 2300, then variable less than 10 mph. * Chance Lightning....20 percent over the Palouse/Hells Canyon...and 25 percent toward the Clearwater/Nez Perce. * CWR (> 0.10 Inch)...10 percent. .THURSDAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....68-78 valleys and 55-65 ridges. * Min Humidity........24-34 percent. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............Northeast 5-15 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 8 kft agl after 1300. * Transport Winds.....Northeast 10 mph. * Chance Lightning....0 percent. * CWR (> 0.10 Inch)...0 percent. .FRIDAY...Partly cloudy. Lows 40-50. Highs 65-75. Min humidities 15-25 percent. Northwest winds 5-10 mph. .SATURDAY...Mostly clear. Lows 45-55. Highs 70-80. Min humidities 15-25 percent. South winds 10-15 mph. .SUNDAY...Mostly clear. Lows 45-55. Highs 75-85. Southwest winds 10-15 mph. .MEMORIAL DAY...Partly cloudy. Lows 45-55. Highs 70-80. .TUESDAY...Cooler. Mostly cloudy with chance of rain showers and snow likely. Chance of precipitation 60 percent. Lows 40-50. Highs 55-65. $$ MTZ104-105-210800- Kootenai-Flathead/Glacier Park- 151 AM MDT Wed May 20 2026 .TODAY... * Sky/Weather.........Mostly cloudy. Chance of rain and snow in the morning. Chance of thunderstorms and snow showers likely in the afternoon. Snow level 6500 feet. * Max Temperature.....60-70 valleys and 45-55 ridges. * Min Humidity........42-52 percent valleys and 62-72 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to variable less than 7 mph. * Ridge Top............Northwest 10-15 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 7 kft agl after 1400. * Transport Winds.....West 10 mph until 1300, then northwest 15 mph. * Chance Lightning....30 percent over the Kootenai...and 40 percent toward the Flathead/Glacier Park. * CWR (> 0.10 Inch)...10 percent over the Kootenai...and 40 percent toward the Flathead/Glacier Park. .TONIGHT... * Sky/Weather.........Partly cloudy. Chance of rain showers and slight chance of thunderstorms. Snow level 6000 feet. * Min Temperature.....30-40. * Max Humidity........90-100 percent valleys and 76-86 percent ridges. * 20-Foot Winds....... * Lower Elevation......Variable less than 5 mph in the evening becoming downslope/downvalley 1-3 mph. * Ridge Top............North 5-15 mph. * Mixing Height.......5 kft agl until 2000. Below 500 ft to 1 kft agl after 2300. * Transport Winds.....North 15 mph until 0100, then 10 mph. * Chance Lightning....15 percent. * CWR (> 0.10 Inch)...10 percent. .THURSDAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....65-75 valleys and 50-60 ridges. * Min Humidity........19-29 percent valleys and 35-45 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............North 5-10 mph becoming west in the afternoon. * Mixing Height.......1-2 kft agl until 0900. 9 kft agl after 1300. * Transport Winds.....North 10 mph until 1500, then west 10 mph. * Chance Lightning....0 percent over the Kootenai...and near 0 percent toward the Flathead/Glacier Park. * CWR (> 0.10 Inch)...0 percent. .FRIDAY...Partly cloudy. Lows 40-50. Highs 60-70. Min humidities 20-30 percent. Southwest winds 10-15 mph. .SATURDAY...Partly cloudy. Lows 40-50. Highs 65-75. Min humidities 20-30 percent. Southwest winds 10-15 mph. .SUNDAY...Partly cloudy. Lows 45-55. Highs 70-80. Southwest winds 15-25 mph. .MEMORIAL DAY...Partly cloudy with slight chance of rain. Chance of rain 20 percent. Lows 45-55. Highs 65-75. .TUESDAY...Cooler. Mostly cloudy with chance of rain. Chance of rain 40 percent. Lows 40-50. Highs 55-65. $$ MTZ106-108-210800- West Lolo-East Lolo- 151 AM MDT Wed May 20 2026 .TODAY... * Sky/Weather.........Partly cloudy. Chance of thunderstorms in the afternoon. Snow level 7000 feet. * Max Temperature.....58-68 valleys and 48-58 ridges. * Min Humidity........41-51 percent valleys and 49-59 percent ridges. * 20-Foot Winds....... * Lower Elevation......West 5-15 mph. * Ridge Top............West 5-15 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 7 kft agl after 1500. * Transport Winds.....West 15 mph. * Chance Lightning....40 percent. * CWR (> 0.10 Inch)...10 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. Rain showers likely and slight chance of thunderstorms. Slight chance of rain after midnight. Snow level 6500 feet. * Min Temperature.....30-40. * Max Humidity........82-92 percent. * 20-Foot Winds....... * Lower Elevation......North 5-10 mph. * Ridge Top............North 5-10 mph. * Mixing Height.......4 kft agl until 2000, then below 500 ft to 1 kft agl. * Transport Winds.....Northwest 15 mph until 2300, then north 10 mph. * Chance Lightning....25 percent. * CWR (> 0.10 Inch)...30 percent over the West Lolo...and 50 percent toward the East Lolo. .THURSDAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....60-70 valleys and 53-63 ridges. * Min Humidity........20-30 percent valleys and 30-40 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............North 5-10 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 8 kft agl after 1300. * Transport Winds.....North 10 mph. * Chance Lightning....0 percent over the West Lolo...and near 0 percent toward the East Lolo. * CWR (> 0.10 Inch)...0 percent. .FRIDAY...Partly cloudy. Lows 40-50. Highs 65-75. Min humidities 15-25 percent. West winds 5-10 mph. .SATURDAY...Mostly clear. Lows 40-50. Highs 70-80. Min humidities 15-25 percent. Southwest winds 10-15 mph. .SUNDAY...Mostly clear. Lows 45-55. Highs 70-80. Southwest winds 10-15 mph. .MEMORIAL DAY...Partly cloudy. Lows 45-55. Highs 70-80. .TUESDAY...Cooler. Partly cloudy with chance of rain. Chance of rain 30 percent. Lows 40-50. Highs 55-65. $$ MTZ107-210800- Flathead Reservation- 151 AM MDT Wed May 20 2026 .TODAY... * Sky/Weather.........Mostly cloudy. Slight chance of rain in the morning. Chance of thunderstorms in the afternoon. Snow level 7000 feet. * Max Temperature.....60-65 valleys and 40-45 ridges. * Min Humidity........48-58 percent valleys and 68-78 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to variable less than 7 mph. * Ridge Top............West 5-15 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900, then 2 kft agl until 1000, then 5 kft agl until 1200, then 7 kft agl until 1700, then 5 kft agl. * Transport Winds.....West 10 mph until 1400, then northwest 15 mph. * Chance Lightning....40 percent. * CWR (> 0.10 Inch)...50 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. Rain showers likely and slight chance of thunderstorms. Snow level 6500 feet. * Min Temperature.....35-40. * Max Humidity........82-92 percent valleys and 93 percent ridges. * 20-Foot Winds....... * Lower Elevation......North 5-10 mph. * Ridge Top............North 5-10 mph. * Mixing Height.......4 kft agl until 1900. Below 500 ft to 1 kft agl after 2200. * Transport Winds.....North 15 mph until 2300, then variable less than 10 mph. * Chance Lightning....20 percent. * CWR (> 0.10 Inch)...40 percent over areas west of Highway 93...and 10 percent toward the Mission Mtns and areas east of Highway 93. .THURSDAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....65-70 valleys and 45-50 ridges. * Min Humidity........30-40 percent valleys and 37-47 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............North 5-15 mph. * Mixing Height.......Below 500 ft to 1 kft agl until 0900. 7 kft agl after 1300. * Transport Winds.....North 10 mph. * Chance Lightning....0 percent. * CWR (> 0.10 Inch)...0 percent. .FRIDAY...Partly cloudy. Lows 40-50. Highs 65-75. Min humidities 20-30 percent. South winds 5-10 mph. .SATURDAY...Partly cloudy. Lows 45-55. Highs 70-80. Min humidities 20-30 percent. Southwest winds 5-10 mph. .SUNDAY...Partly cloudy. Lows 45-55. Highs 75-85. Southwest winds 10-15 mph. .MEMORIAL DAY...Partly cloudy with slight chance of rain showers and thunderstorms. Chance of precipitation 20 percent. Lows 50-60. Highs 70-80. .TUESDAY...Cooler. Partly cloudy with chance of rain. Chance of rain 40 percent. Lows 45-55. Highs 60-70. $$ MTZ109-210800- Bitterroot- 151 AM MDT Wed May 20 2026 .TODAY... * Sky/Weather.........Mostly cloudy. Slight chance of thunderstorms in the afternoon. Snow level 7500 feet. * Max Temperature.....65-70 valleys and 45-50 ridges. * Min Humidity........33-43 percent valleys and 47-57 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming northwest 5-15 mph in the afternoon. * Ridge Top............West 10-20 mph. * Mixing Height.......1-2 kft agl until 0900. 7 kft agl after 1100. * Transport Winds.....West 10 mph until 1400, then 20 mph. * Chance Lightning....25 percent over the Darby, Sula, and West Fork Districts...and 30 percent toward areas north of Hamilton. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. Chance of rain showers, snow showers and slight chance of thunderstorms. Chance of rain and snow after midnight. Snow level 7000 feet. * Min Temperature.....30-40. * Max Humidity........79-89 percent. * 20-Foot Winds....... * Lower Elevation......North 10-15 mph becoming variable less than 5 mph after midnight. * Ridge Top............Northwest 10-20 mph becoming north 5-10 mph after midnight. * Mixing Height.......4 kft agl until 2000. Below 500 ft to 1 kft agl after 2100. * Transport Winds.....Northwest 20 mph until 2100, then north 10 mph. * Chance Lightning....25 percent. * CWR (> 0.10 Inch)...10 percent over the Darby, Sula, and West Fork Districts...and 50 percent toward areas north of Hamilton. .THURSDAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....65-70 valleys and 50-55 ridges. * Min Humidity........20-30 percent valleys and 35-45 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to variable less than 7 mph. * Ridge Top............North 5-15 mph. * Mixing Height.......2 kft agl until 1000. 8 kft agl after 1400. * Transport Winds.....Northeast 10 mph until 1600, then 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .FRIDAY...Partly cloudy. Lows 35-45. Highs 60-70. Min humidities 15-25 percent. Northwest winds 10-15 mph. .SATURDAY...Mostly clear. Lows 40-50. Highs 65-75. Min humidities 10-20 percent. Southwest winds 10-15 mph. .SUNDAY...Partly cloudy. Lows 45-55. Highs 70-80. Southwest winds 10-20 mph. .MEMORIAL DAY...Partly cloudy. Lows 45-55. Highs 70-80. .TUESDAY...Cooler. Mostly cloudy with chance of rain and snow. Chance of precipitation 30 percent. Lows 40-50. Highs 55-65. $$ MTZ110-111-210800- Deerlodge/West Beaverhead-East Beaverhead- 151 AM MDT Wed May 20 2026 .TODAY... * Sky/Weather.........Partly cloudy. Slight chance of thunderstorms in the afternoon. Snow level 7500 feet. * Max Temperature.....55-65 valleys and 45-50 ridges. * Min Humidity........26-36 percent valleys and 33-43 percent ridges. * 20-Foot Winds....... * Lower Elevation......West 5-15 mph. * Ridge Top............West 5-15 mph. * Mixing Height.......2 kft agl until 0900. 8 kft agl after 1500. * Transport Winds.....West 10 mph until 1300, then 15 mph. * Chance Lightning....30 percent over the Deerlodge/West Beaverhead...and 25 percent toward the East Beaverhead. * CWR (> 0.10 Inch)...10 percent. .TONIGHT... * Sky/Weather.........Mostly cloudy. Rain showers, snow showers and slight chance of thunderstorms in the evening, then chance of snow and rain after midnight. Snow level 7000 feet. * Min Temperature.....30-35. * Max Humidity........89-99 percent valleys and 82-92 percent ridges. * 20-Foot Winds....... * Lower Elevation......North 10-20 mph. * Ridge Top............North 10-20 mph. * Mixing Height.......5 kft agl until 2000. Below 500 ft to 1 kft agl after 2200. * Transport Winds.....North 15 mph until 0200, then 15 mph. * Chance Lightning....25 percent over the Deerlodge/West Beaverhead...and 20 percent toward the East Beaverhead. * CWR (> 0.10 Inch)...30 percent. .THURSDAY... * Sky/Weather.........Partly cloudy. Slight chance of snow. * Max Temperature.....55-60 valleys and 45-50 ridges. * Min Humidity........24-34 percent valleys and 31-41 percent ridges. * 20-Foot Winds....... * Lower Elevation......North 15-25 mph. * Ridge Top............North 15-25 mph. * Mixing Height.......2 kft agl until 0900. 9 kft agl after 1600. * Transport Winds.....North 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...10 percent. .FRIDAY...Partly cloudy. Lows 30-40. Highs 60-70. Min humidities 15-25 percent. West winds 10-20 mph. .SATURDAY...Partly cloudy. Lows 35-45. Highs 65-75. Min humidities 10-20 percent. Southwest winds 10-15 mph. .SUNDAY...Partly cloudy. Lows 40-50. Highs 70-80. Southwest winds 10-20 mph. .MEMORIAL DAY...Partly cloudy. Lows 45-55. Highs 70-80. .TUESDAY...Cooler. Partly cloudy with chance of rain showers and slight chance of thunderstorms. Chance of precipitation 30 percent. Lows 40-50. Highs 60-70. $$