Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
322 FXUS65 KMSO 221837 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1237 PM MDT Wed May 22 2024 ...HEAVY SNOW IN THE HIGHER TERRAIN ACROSS LEMHI COUNTY INTO SOUTHWEST MONTANA TONIGHT... .DISCUSSION...The winter storm for the higher elevations remains on track from previous forecasts. Confidence has increased in the details of the impacts enough that we upgraded to winter storm warnings above 5,000 ft in west central and southwest Montana. Snow amounts will vary considerably with elevation, but elevations above 5,000 ft will see significant impacts due to high snow rates over 1 inch per hour for several hours. Also, where the leaves have come out on the trees, the heavy, wet snow can cause significant damage due to snow loading breaking branches, which may also lead to some power outages. There will be a break between systems to end the week, though the region will remain under a cool, showery pattern. Memorial Day weekend will start off on Saturday with another cutoff low moving into the region and causing high elevation snow. All guidance so far is pointing to an overall warmer system with a little less precipitation. So fewer snow impacts, but an overall cool and wet start to Memorial Day weekend. Conditions will generally improve through the weekend with above average temperatures expected by Monday. Overall, the pattern remains active next week, but ensembles agree well on a 2 to 4 day period dominated by a ridge at some point. There is, however, considerable differences in the timing other than it will be too late for Memorial Day. && .AVIATION...A cutoff low moving into the northern Rockies region today is causing widespread rain showers and mountain obscurations. Snow levels will drop down tonight causing lower ceilings overnight tonight. Timing is very uncertain, but snow levels are expected to reach the surface sometime tonight at terminal KBTM, and will be near the surface there by 23/13Z. Heavy precipitation, rain at first then snow, is expected at KBTM between 23/01Z and 23/13Z. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Winter Storm Warning from 6 PM this evening to noon MDT Thursday for Bitterroot/Sapphire Mountains...Butte/Blackfoot Region. ID...Winter Weather Advisory from 6 PM this evening to noon MDT Thursday for Eastern Lemhi County...Western Lemhi County. && $$