Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
761 FXUS65 KMSO 051938 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 138 PM MDT Sun May 5 2024 .DISCUSSION...A well formed closed low pressure circulation is moving from Oregon into southern Idaho this afternoon. This feature will continue to travel east over the coming days before getting wrapped up in a longer wave by Tuesday night. In the meantime, it will continue to push moisture up from the south. Snow levels tonight will drop down to about 5000 feet. As a result of this cool-down and available moisture, snow will grace the higher roadways of Lemhi County and southwest Montana tonight. Motorists traveling along Highways 28 and 93 in Lemhi County tonight and Monday morning should be prepared for a few inches of snow in the vicinities of Lost Trail Pass and Gilmore Summit. Backcountry travelers in the Clearwater, Beaverhead, Lemhi, and southern Bitterroot Ranges should expect wintry conditions and potential for about 6 to 12 inches of snow by Monday morning over the higher terrain. Further north, the Missions and Swans will also see a solid snowfall tonight. A cold front passage later in the day on Monday will bring gusty west winds to the entire Northern Rockies. Windy conditions will continue on Tuesday as a longer wave amplifies over the Northern Rockies. Strong low pressure east of the Continental Divide will bring wraparound moisture to the Divide in the Glacier National Park vicinity including Marias Pass. This scenario will be favorable for snow in these areas above about 4000 to 5000 feet. Current guidance is showing about 3 to 6 inches for Marias Pass by Wednesday morning. Neighboring peaks of the Mission, Swan, and Flathead Ranges, as well as the high terrain of Glacier Park, will see closer to a foot or more. High pressure develops over the region on Thursday with good agreement among ensemble solutions to last into the weekend. && .AVIATION... Rain shower activity is increasing from south to north this afternoon. Precipitation intensity will increase this evening, resulting in periods of low visibility and ceilings after about 06/00z. Wind direction will gradually turn westerly by Monday morning. Precipitation will transition to a rain-snow mix overnight tonight. Expect precipitation to obscure terrain throughout the Northern Rockies through Monday. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...Winter Weather Advisory from 9 PM this evening to noon MDT Monday for Eastern Lemhi County. && $$