Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
685 FXUS65 KMSO 170820 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 220 AM MDT Mon Jun 17 2024 ...Winter Storm to make backcountry travel hazardous today through Tuesday... .DISCUSSION...Precipitation is increasing early this morning as a mid level low works into north-central Idaho and west-central Montana. Snow levels as of 2am MDT have dropped to around 5500 feet along the Idaho/Montana border, closer to 6000 feet in Southwest Montana. Snow levels are expected to lower closer to 4500 feet later this morning for much of the area. One exception will be under the band of heavier precipitation northwest of the low center, where snow levels could briefly fall to 3500-4000 feet. Precipitation becomes showery (perhaps even a few thunderstorms) this afternoon with considerable showers continuing tonight into Tuesday as snow levels remain around 5000-5500 feet. All in all, the impacts remain the same: Backcountry travel will be very difficult. Snow on trees could cause breaking branches and power outages are possible. Hypothermia is also a risk for those unprepared for the cold and raw conditions. Models continue to show another disturbance digging south out of Canada Tuesday morning. This will provide a focus for snow showers across northwest Montana, particularly in the Glacier Park region. Gardeners beware of frost potential on Wednesday morning in valley locations that see partial clearing. Currently, models show this clearing from the Mission Valley southward into Lemhi County. Please stay tuned for the latest low temperature forecast as sensitive plants may need to be covered. Model ensembles agree (nearly 100%) on a warming trend for the rest of the week with scattered afternoon showers each day. Daytime temperatures peak on Sunday about 15 degrees above normal (upper 80s western Montana valleys, low/mid 90s for north-central Idaho). && .AVIATION...Precipitation will increase in coverage this morning as a mid level low moves into Idaho and western Montana. Generally, precipitation in the form of rain is expected below 4500 feet. However, there is a potential (20-30% chance) for localized snow accumulations down to valley floors under a heavier precipitation band just northwest of the low center this morning, mainly from west- central Montana into north-central Idaho. Precipitation turns showery (a few thunderstorms as well) late today as northwest flow takes over with periods of showers into Tuesday. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Winter Storm Warning until 6 AM MDT Tuesday for Bitterroot/Sapphire Mountains...Butte/Blackfoot Region. Winter Weather Advisory from 6 AM Monday to 9 AM MDT Tuesday for West Glacier Region. Winter Weather Advisory from 3 AM to 11 AM MDT Monday for Missoula/Bitterroot Valleys. Winter Storm Warning from 3 AM Monday to 6 AM MDT Tuesday for Potomac/Seeley Lake Region. ID...Winter Storm Warning until 5 AM PDT Tuesday for Southern Clearwater Mountains. Winter Weather Advisory until 2 PM MDT Monday for Eastern Lemhi County...Western Lemhi County. && $$