Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
874 FXUS65 KMSO 061853 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1253 PM MDT Mon May 6 2024 .DISCUSSION...A low pressure system moving through central and eastern Montana will maintain cool, wet and breezy conditions over western Montana and north central Idaho through Wednesday. The two main concerns with this pattern will be for higher elevation snow and strong winds, detailed below. High elevation snow: Precipitation will become widespread over western Montana and north central Idaho once again during the day Tuesday, lasting into Wednesday. Snow levels will lower to roughly 4000 feet by early Wednesday morning, resulting in some hefty snowfall totals in the terrain, especially above 5000 feet along the Continental Divide. Forecast models show a 50 to 60 percent chance of 6" of snow or more for locations such as Marias Pass, Georgetown Lake, MacDonald Pass and Homestake Pass. Even the high valleys of southwest Montana (Butte, Anaconda, Philipsburg) will see snowfall, with a 70 to 80 percent chance of seeing 2" of snow by mid day Wednesday. Winter Weather Advisories have been issued for the Glacier National Park and Butte/Blackfoot regions to account for snow travel and slick roads. Winds: Breezy winds are already evident this afternoon, with gusts up to 40 mph possible through early this evening. Winds will decrease for most locations overnight, but become breezy once again Tuesday morning. The strongest winds are expected to be focused over the higher terrain along the Continental Divide and into southwest Montana along the Highway 12 corridor from Garrison Junction to MacDonald Pass and Interstate 90 from Drummond to Homestake Pass. Gusts to 55 mph in these areas could cause minor tree damage and make travel difficult for high profile vehicles. In addition, Flathead Lake will see breezy winds with gusts up to near 40 mph, causing choppy water conditions for small craft. Wind highlights have been issued to address these concerns. Winds are expected to decrease by late Tuesday evening for valley locations. However, breezy winds with gusts to 30 mph will likely continue in the terrain and may combine with snow to cause locally lowered visibility into Wednesday morning, especially for MacDonald and Marias Passes. For Thursday into early next week, the majority of forecast models (70 percent) point to an overall dry and warm weather pattern as high pressure builds in from the west. The other 30 percent of models show a closed low pressure system moving just to the south of the region, which would lead to showers and a less robust warm up. If the 70 percent of model solutions is correct, temperatures would warm into the upper 70s and low 80s for most valley locations by Mother`s Day! && .AVIATION...A cool, wet, and windy weather pattern will remain in place across the Northern Rockies through the next 36 hours. This will keep periodic showers and lower ceilings in place across the area and at most airfields. Conditions will gradually deteriorate tonight as a secondary shortwave trough rotates through the region. The snow level will lower to around 4000 feet by Tuesday night with accumulations, along with reduced visibility and significantly lowered ceiling heights, expected at KBTM. Breezy winds are also likely throughout the Northern Rockies with gusts to 30 knots possible during the afternoon at KGPI, KMSO, and KBTM. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Winter Weather Advisory from 6 PM Tuesday to 11 AM MDT Wednesday for West Glacier Region above 4000 feet. Lake Wind Advisory from 9 AM to 8 PM MDT Tuesday for Flathead/Mission Valleys. Wind Advisory from 6 AM to 9 PM MDT Tuesday for Butte/Blackfoot Region. Winter Weather Advisory from 9 PM Tuesday to 11 AM MDT Wednesday for Butte/Blackfoot Region. ID...None. && $$