FNUS55 KMSO 210846 FWFMSO Fire Weather Planning Forecast for Wrn Montana and N Cntrl Idaho National Weather Service Missoula MT 246 AM MDT Tue Apr 21 2026 .DISCUSSION... Idaho (Zones 102 and 103): A ridge of high pressure will be the dominate weather feature over the region for one more day. The ridge will allow for hot and dry conditions, with high temperatures running 20 to 30 degrees above normal. MinRH values will again lower into the mid teens this afternoon. The weather pattern changes late this evening into tomorrow morning. 48-hour precipitation totals ending Friday morning will range between 1 to 2 inches, with a 20 to 40 percent probability of exceeding 2 inches. Elevations above 5000 feet will receive 3 to 6 inches of snow during the same period. Temperatures will continue to run below normal through the weekend, with isolated showers lingering over the region. Northwest MT (Zones 104 and 105): A ridge of high pressure will be the dominate weather feature over the region for one more day. The ridge will allow for hot and dry conditions, with high temperatures running 20 to 30 degrees above normal. MinRH values will again lower into the mid teens this afternoon. The weather pattern changes late this evening into tomorrow morning. 48-hour precipitation totals ending Friday morning will range between 0.50 to 1.25 inches. Elevations above 5000 feet in the Flathead NF will receive 3 to 6 inches of snow and a 70 percent probability for up to 10 inches in the Swan Range during the same period. Temperatures will continue to run below normal through the weekend, with isolated showers lingering over the region. West Central MT (Zones 106, 107 and 108): A ridge of high pressure will be the dominate weather feature over the region for one more day. The ridge will allow for hot and dry conditions, with high temperatures running 20 to 30 degrees above normal. MinRH values will again lower into the mid teens this afternoon. The weather pattern changes late this evening into tomorrow morning. 48-hour precipitation totals ending Friday morning will range between 0.50 to 1.25 inches. Elevations above 5000 feet in the Mission Range and Rattlesnake region will receive 6 to 9 inches of snow and a 60 to 80 percent probability of exceeding 12 inches during the same period. Temperatures will continue to run below normal through the weekend, with isolated showers lingering over the region. Southwest MT (Zones 109, 110 and 111): A ridge of high pressure will be the dominate weather feature over the region for one more day. The ridge will allow for hot, dry and breezy conditions, with high temperatures running 20 to 30 degrees above normal. The combination of MinRH values in the low teens and wind gusts between 25 to 35 mph will allow for near critical fire weather conditions. The weather pattern changes late this evening into Wednesday. 48-hour precipitation totals ending Friday morning will range between 0.50 to 1 inch. The mountains in the Beaverhead/Deerlodge NF will receive 6 to 9 inches of snow with isolated higher amounts during the same period. Temperatures will continue to run below normal through the weekend, with isolated showers lingering over the region. IDZ102-103-220900- Palouse/Hells Canyon-Clearwater/Nez Perce- 146 AM PDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....75-85 valleys and 65-75 ridges. * Min Humidity........20-30 percent. * 20-Foot Winds....... * Lower Elevation......Calm to becoming south 5-15 mph in the afternoon. * Ridge Top............South 10-20 mph. * Mixing Height.......1-2 kft agl until 1100. 10 kft agl after 1400. * Transport Winds.....Southeast 15 mph until 1300, then south 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent..TONIGHT... * Sky/Weather.........Partly cloudy. Chance of rain showers and slight chance of thunderstorms. * Min Temperature.....45-50 valleys and 35-40 ridges. * Max Humidity........80-90 percent. * 20-Foot Winds....... * Lower Elevation......West 5-10 mph. * Ridge Top............South 5-15 mph in the evening. * Mixing Height.......7 kft agl until 1900, then below 500 ft to 1 kft agl. * Transport Winds.....Southwest 10 mph until 2000, then northwest 10 mph. * Chance Lightning....30 percent. * CWR (> 0.10 Inch)...50 percent over the Palouse/Hells Canyon...and 10 percent toward the Clearwater/Nez Perce. .WEDNESDAY... * Sky/Weather.........Rain showers and slight chance of thunderstorms. Snow showers in the afternoon. Snow level 6000 feet. * Max Temperature.....50-60 valleys and 40-45 ridges. * Min Humidity........70-80 percent. * 20-Foot Winds....... * Lower Elevation......West 5-15 mph. * Ridge Top............West 5-15 mph. * Mixing Height.......4 kft agl. * Transport Winds.....West 15 mph until 1200, then 20 mph. * Chance Lightning....Near 0 percent over the Palouse/Hells Canyon...and 20 percent toward the Clearwater/Nez Perce. * CWR (> 0.10 Inch)...100 percent. .THURSDAY...Mostly cloudy with rain and snow. Chance of precipitation 80 percent. Lows 35-45. Highs 45-55. Min humidities 40-50 percent. West winds 5-15 mph. .FRIDAY...Mostly cloudy with chance of rain and snow. Chance of precipitation 40 percent. Lows 30-40. Highs 45-55. Min humidities 30-40 percent. North winds 10-15 mph. .SATURDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 50-60. Northeast winds 10-15 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 30-40. Highs 50-60. .MONDAY...Partly cloudy with slight chance of rain and snow. Chance of precipitation 20 percent. Lows 30-40. Highs 55-65. $$ MTZ104-105-220900- Kootenai-Flathead/Glacier Park- 246 AM MDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....80-85 valleys and 60-70 ridges. * Min Humidity........11-17 percent valleys and 25-35 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............Southwest 5-15 mph. * Mixing Height.......3 kft agl until 1200. 9 kft agl after 1500. * Transport Winds.....Southeast 10 mph until 1600, then south 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. * Min Temperature.....40-45. * Max Humidity........75-85 percent valleys and 64-74 percent ridges. * 20-Foot Winds....... * Lower Elevation......Downslope/downvalley 1-3 mph. * Ridge Top............South 5-15 mph becoming southeast after midnight. * Mixing Height.......7 kft agl until 1900. 1-2 kft agl after 2000. * Transport Winds.....South 10 mph until 2200, then northwest 10 mph until 2300, then northeast 10 mph until 2400, then west 10 mph until 0200, then north 10 mph. * Chance Lightning....20 percent over the Kootenai...and near 0 percent toward the Flathead/Glacier Park. * CWR (> 0.10 Inch)...0 percent. .WEDNESDAY... * Sky/Weather.........Mostly cloudy. Rain showers. Slight chance of thunderstorms in the afternoon. * Max Temperature.....55-65 valleys and 45-55 ridges. * Min Humidity........54-64 percent valleys and 62-72 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to variable less than 7 mph. * Ridge Top............Southwest 10-20 mph. * Mixing Height.......2 kft agl until 1000, then 5 kft agl until 1500, then 4 kft agl. * Transport Winds.....Northwest 10 mph until 1300, then west 15 mph. * Chance Lightning....25 percent over the Kootenai...and 30 percent toward the Flathead/Glacier Park. * CWR (> 0.10 Inch)...90 percent. .THURSDAY...Colder. Mostly cloudy with snow and rain. Chance of precipitation 80 percent. Lows 30-40. Highs 40-50. Min humidities 30-40 percent. Northwest winds 10-20 mph. .FRIDAY...Mostly cloudy with chance of snow. Chance of snow 30 percent. Lows 25-35. Highs 40-50. Min humidities 25-35 percent. North winds 10-15 mph. .SATURDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 40-50. Northeast winds 10-15 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 45-55. .MONDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 50-60. $$ MTZ106-108-220900- West Lolo-East Lolo- 246 AM MDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....73-83 valleys and 65-75 ridges. * Min Humidity........10-20 percent valleys and 19-29 percent ridges. * 20-Foot Winds....... * Lower Elevation......Southeast 5-15 mph. * Ridge Top............Southeast 5-15 mph becoming southwest in the afternoon. * Mixing Height.......3 kft agl until 1200. 11 kft agl after 1500. * Transport Winds.....Southeast 10 mph until 1300, then south 20 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. * Min Temperature.....40-45. * Max Humidity........71-81 percent valleys and 64-74 percent ridges. * 20-Foot Winds....... * Lower Elevation......Southwest 5-10 mph. * Ridge Top............Southwest 5-15 mph becoming southeast after midnight. * Mixing Height.......8 kft agl until 1900. Below 500 ft to 1 kft agl after 2000. * Transport Winds.....Southwest 15 mph until 2100, then west 10 mph until 0500, then southwest 10 mph. * Chance Lightning....15 percent over the West Lolo...and near 0 percent toward the East Lolo. * CWR (> 0.10 Inch)...0 percent. .WEDNESDAY... * Sky/Weather.........Mostly cloudy. Rain showers and slight chance of thunderstorms. Snow in the afternoon. Snow level 7500 feet. * Max Temperature.....53-63 valleys and 43-53 ridges. * Min Humidity........50-60 percent. * 20-Foot Winds....... * Lower Elevation......Southwest 10-20 mph. * Ridge Top............Southwest 5-15 mph increasing to west 15-25 mph in the afternoon. * Mixing Height.......2 kft agl until 0900, then 3 kft agl until 1000, then 5 kft agl until 1100, then 8 kft agl until 1400, then 5 kft agl. * Transport Winds.....Southwest 15 mph until 1200, then 25 mph. * Chance Lightning....25 percent. * CWR (> 0.10 Inch)...80 percent. .THURSDAY...Colder. Cloudy with snow and rain. Chance of precipitation 90 percent. Lows 35-45. Highs 40-50. Min humidities 35-45 percent. West winds 10-20 mph. .FRIDAY...Mostly cloudy with chance of snow. Chance of snow 40 percent. Lows 25-35. Highs 40-50. Min humidities 30-40 percent. North winds 10-15 mph. .SATURDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 20-30. Highs 40-50. Northeast winds 10-15 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 45-55. .MONDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 30-40. Highs 50-60. $$ MTZ107-220900- Flathead Reservation- 246 AM MDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....80-85 valleys and 55-60 ridges. * Min Humidity........7-17 percent valleys and 22-32 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming upslope/upvalley 4-8 mph in the afternoon. * Ridge Top............South 10-20 mph becoming west 10-15 mph in the afternoon. * Mixing Height.......3 kft agl until 1200. 9 kft agl after 1500. * Transport Winds.....East 10 mph until 1500, then south 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. * Min Temperature.....45-50. * Max Humidity........66-76 percent valleys and 73-83 percent ridges. * 20-Foot Winds....... * Lower Elevation......West 5-10 mph. * Ridge Top............Southwest 5-15 mph becoming southeast after midnight. * Mixing Height.......7 kft agl until 1900. Below 500 ft to 1 kft agl after 2000. * Transport Winds.....Southwest 10 mph until 2100, then variable less than 10 mph until 2200, then north 10 mph until 0500, then variable less than 10 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .WEDNESDAY... * Sky/Weather.........Mostly cloudy. Rain showers and slight chance of thunderstorms. * Max Temperature.....60-65 valleys and 45-50 ridges. * Min Humidity........51-61 percent valleys and 63-73 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming 10-15 mph in the afternoon. * Ridge Top............Southwest 5-15 mph increasing to west 15-25 mph in the afternoon. * Mixing Height.......2 kft agl until 1000, then 4 kft agl. * Transport Winds.....Southwest 10 mph until 1200. 25 mph after 1500. * Chance Lightning....25 percent. * CWR (> 0.10 Inch)...80 percent. .THURSDAY...Cooler. Cloudy with rain and snow. Chance of precipitation 90 percent. Lows 35-45. Highs 45-55. Min humidities 35-45 percent. West winds 10-20 mph. .FRIDAY...Mostly cloudy with chance of snow and rain. Chance of precipitation 30 percent. Lows 30-40. Highs 45-55. Min humidities 25-35 percent. North winds 10-15 mph. .SATURDAY...Partly cloudy. Lows 25-35. Highs 45-55. Northeast winds 10-15 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 50-60. .MONDAY...Partly cloudy with slight chance of rain and snow. Chance of precipitation 20 percent. Lows 30-40. Highs 50-60. $$ MTZ109-220900- Bitterroot- 246 AM MDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....80-85 valleys and 60-65 ridges. * Min Humidity........11-20 percent valleys and 19-29 percent ridges. * 20-Foot Winds....... * Lower Elevation......Calm to becoming south 5-15 mph in the afternoon. * Ridge Top............South 10-20 mph. * Mixing Height.......2 kft agl until 1100. 11 kft agl after 1400. * Transport Winds.....Southeast 15 mph until 1300, then south 20 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. * Min Temperature.....35-45. * Max Humidity........61-71 percent. * 20-Foot Winds....... * Lower Elevation......South 10-15 mph. * Ridge Top............South 10-15 mph. * Mixing Height.......8 kft agl until 1900. 1-2 kft agl after 2000. * Transport Winds.....South 15 mph. * Chance Lightning....15 percent over the Darby, Sula, and West Fork Districts...and near 0 percent toward areas north of Hamilton. * CWR (> 0.10 Inch)...0 percent. .WEDNESDAY... * Sky/Weather.........Snow in the morning. Rain showers and slight chance of thunderstorms. Snow showers in the afternoon. Snow level 7000 feet. * Max Temperature.....60-65 valleys and 40-45 ridges. * Min Humidity........47-57 percent valleys and 61-71 percent ridges. * 20-Foot Winds....... * Lower Elevation......Southwest 10-20 mph. * Ridge Top............Southwest 5-15 mph increasing to west 15-25 mph in the afternoon. * Mixing Height.......3 kft agl until 0900. 6 kft agl after 1300. * Transport Winds.....Southwest 15 mph until 1300, then west 25 mph. * Chance Lightning....20 percent over the Darby, Sula, and West Fork Districts...and 25 percent toward areas north of Hamilton. * CWR (> 0.10 Inch)...90 percent. .THURSDAY...Colder. Cloudy with snow and rain. Chance of precipitation 80 percent. Lows 30-40. Highs 40-50. Min humidities 35-45 percent. West winds 10-20 mph. .FRIDAY...Mostly cloudy with snow likely. Chance of snow 70 percent. Lows 25-35. Highs 35-45. Min humidities 30-40 percent. North winds 10-20 mph. .SATURDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 20-30. Highs 40-50. Northeast winds 10-20 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 45-55. .MONDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 45-55. $$ MTZ110-111-220900- Deerlodge/West Beaverhead-East Beaverhead- 246 AM MDT Tue Apr 21 2026 .TODAY... * Sky/Weather.........Partly cloudy. * Max Temperature.....75-80 valleys and 60-70 ridges. * Min Humidity........10-18 percent. * 20-Foot Winds....... * Lower Elevation......South 15-25 mph. * Ridge Top............South 10-20 mph increasing to 20-30 mph in the afternoon. * Mixing Height.......Below 500 ft to 1 kft agl until 1000. 11 kft agl after 1400. * Transport Winds.....South 15 mph until 1200. 30 mph after 1500. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .TONIGHT... * Sky/Weather.........Partly cloudy. * Min Temperature.....35-45. * Max Humidity........41-51 percent. * 20-Foot Winds....... * Lower Elevation......South 15-25 mph. * Ridge Top............South 15-25 mph. * Mixing Height.......11 kft agl until 1900. Below 500 ft to 1 kft agl after 2000. * Transport Winds.....South 30 mph until 2000, then 15 mph. * Chance Lightning....Near 0 percent. * CWR (> 0.10 Inch)...0 percent. .WEDNESDAY... * Sky/Weather.........Partly cloudy. Rain showers and snow showers. Slight chance of thunderstorms in the afternoon. Snow level 7500 feet. * Max Temperature.....55-65 valleys and 43-53 ridges. * Min Humidity........28-38 percent valleys and 37-47 percent ridges. * 20-Foot Winds....... * Lower Elevation......South 25-35 mph. * Ridge Top............Southwest 25-35 mph. * Mixing Height.......3 kft agl until 0900, then 5 kft agl until 1000, then 6 kft agl until 1100, then 9 kft agl until 1500, then 7 kft agl until 1700, then 6 kft agl. * Transport Winds.....South 20 mph until 0800, then southwest 30 mph until 1700, then west 25 mph. * Chance Lightning....25 percent over the Deerlodge/West Beaverhead...and 20 percent toward the East Beaverhead. * CWR (> 0.10 Inch)...70 percent over the Deerlodge/West Beaverhead...and 40 percent toward the East Beaverhead. .THURSDAY...Colder. Cloudy with snow showers. Chance of snow 90 percent. Lows 30-40. Highs 35-45. Min humidities 40-50 percent. West winds 15-25 mph. .FRIDAY...Mostly cloudy with snow likely. Chance of snow 70 percent. Lows 20-30. Highs 30-40. Min humidities 35-45 percent. North winds 10-20 mph. .SATURDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 15-25. Highs 35-45. Northeast winds 10-20 mph. .SUNDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 20-30. Highs 40-50. .MONDAY...Partly cloudy with slight chance of snow. Chance of snow 20 percent. Lows 25-35. Highs 45-55. $$