Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
577 FXUS65 KMSO 280809 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 209 AM MDT Sun Apr 28 2024 .DISCUSSION...Low pressure spinning over the Gulf of Alaska is pushing Pacific moisture into the northwestern U.S. this morning while another low departs the Rocky Mountain West and enters the Great Plains. The Northern Rockies will be between these systems for a short period of time today. Southwest Montana and Lemhi County will get a short break in precipitation while the Pacific system moves closer. In the meantime, northwest Montana, along with Clearwater and Idaho Counties, will see continued precipitation in the form of lower elevation rain and high elevation (above about 5000 ft) snow today. A cold front associated with this system will bring some increasing westerly or southwesterly winds this afternoon ahead of the frontal passage. By Monday, the low will arrive in the Pacific Northwest. Continued frontal dynamics, along with Pacific moisture and a favorable position of the upper level jet will result in moderate precipitation focused on north-central Idaho and the southern Bitterroot Valley. Snow levels will lower to around 3800-4500 feet in these locations. Locations like Elk City, Dixie, Lolo Pass, and Lost Trail Pass could receive 1 to 3 inches of wet snow, while higher elevations of the Clearwater, Bitterroot, Anaconda, and Pintler Mountains could receive 6 to 12 inches of snow. The unsettled and cool pattern continues through the first week of May. Tuesday through Wednesday, a back door cold front will affect the Continental Divide as a closed low forms on the east side. Wraparound moisture from this system will be conducive to a spring snow event for the Glacier Park region and the Divide to include Marias Pass, where there is about a 50% chance of seeing 4 or more inches of snow by Wednesday evening. && .AVIATION...A break in shower activity this morning will make fog a good possibility at KMSO. Otherwise, expect a mostly overcast day with decreasing shower activity and increasing westerly or southwesterly winds with gust to about 20 kts this afternoon. Showers will become more widespread again tonight, especially over the terrain along the Idaho-Montana border. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$