textproduct: Missoula
This forecast discussion was created in the public domain by the National Weather Service. It can be found in its original form here.
DISCUSSION
KEY MESSAGES:
- Weekend Stagnation: high pressure brings drier weather and warming temperatures aloft. This setup is expected to trap cold air in the valleys, leading to strengthening inversions, areas of valley fog, and stagnant conditions.
- Complex System Monday-Tuesday: Moisture moving into stable air/valley inversions will bring risk for freezing rain.
A few things are evident in weather observations around our region. Temperatures in the mountains have warmed 4 to 8 degrees in the past 24 hours, while valleys in some cases cooled a few degrees strengthening valley inversions. The air mass dried some, likely due to frost overnight decreasing fog or stratus potential. Finally, there is a weak southerly gradient warming southern portions of valleys, eroding valley inversions in those locations.
High pressure will continue through Sunday, when remnant atmospheric river moisture moves into northwest MT overnight into Monday morning. While snow levels are expected to quickly rise, cold surface temperatures in valleys will allow for a period of mixed precipitation, most concerningly freezing rain. Our current area of focus is far northwest MT, along and north of US-2 and west of US-93. These areas during the Monday morning commute may experience icy conditions on roadways, add time to or delay your commute if possible. Elsewhere a brief sprinkle is possible throughout the day but the models have backed off on aerial extent and amount of precipitation for Monday. Any sprinkle or light shower in valleys could produce brief but slick conditions.
High pressure rebounds on Tuesday and in valleys where inversions have eroded could see temperatures mid 40s to 50s. The duration of high pressure may allow for the development of air stagnation.
AVIATION
Valley inversions will continue through Sunday. Expect VFR conditions for most locations. Drier surface conditions may alleviate fog or stratus concerns, but fog in the vicinity of KGPI and KMSO Sunday morning will be possible.
MSO WATCHES/WARNINGS/ADVISORIES
MT...None. ID...None.
IMPORTANT This is an independent project and has no affiliation with the National Weather Service or any other agency. Do not rely on this website for emergency or critical information: please visit weather.gov for the most accurate and up-to-date information available.
textproduct.us is built and maintained by Joshua Thayer.