MISSOULA - The region remains under a cool zonal (westerly) flow as a trough departs to the east. This will keep cooler temps, fairly dry & breezy conditions around through Friday. Highs will top out in the mid 50s to low 60s.
Another strong (& pretty chilly for this time of year) system with even cooler air is on tap for the weekend. This will allow snow levels to fall further... perhaps to 4,000' by Saturday evening/Sunday morning. At this point, pass level travel may see *minor* snow impacts, but this will continue to be monitored. Highs will only make it into the upper 40s to low 50s Saturday & Sunday... a good 10° - 20° below average.
As this trough exits to the south and east, winds will transition to a more northerly direction Sunday into Monday. As of now, Sunday, Monday & Tuesday mornings (depending on cloud cover) could see temps dropping low enough to cause a frost or even freeze which could damage sensitive plants. Now's the time to plan ahead: cover sensitive vegetation, bring those vulnerable potted plants inside and make sure outdoor animals have warm shelter and unfrozen water!
