textproduct: Missoula

DISCUSSION

KEY MESSAGES:

- Slippery Travel: Occasional freezing rain and snow will result in slick travel conditions tonight into Saturday morning for mountain passes and a few valley of northwest Montana.

- Weekend Warmth: Temperatures will trend upward through the weekend and peak on Sunday, with widespread highs in the 40s and 50s likely. Riggins Idaho could be in the 60s.

- Monday System: A weak disturbance returns Monday bringing valley rain and mountain snow, followed by warming temperature trends for the remainder of the week.

Some light showers will continue to move through the Northern Rockies today into the overnight hours. The majority of the valleys across the region have warmed to well above freezing this afternoon the threat for freezing rain tonight will be less compared to last night due to winds and clouds minimizing the cooling. A few areas that could still have some pockets of freezing rain will be across northwest Montana especially Highway 93 from Eureka to Whitefish, Highway 2 from West Glacier to Marias Pass and parts of Highway 83 from Swan Lake to Seeley Lake. A very subtle disturbance appears to bring another round of light showers to northwest Montana Saturday afternoon, but the precipitation type will be all rain.

Temperatures will continue to rise each day with Sunday being the warmest. At this time temperatures appear to be mainly in the 40s and 50s for the majority of the valleys with the Riggins Idaho area getting into the 60s. An approaching cold front could cause the valleys to fully mix by Sunday afternoon which cause temperatures to be warmer than already forecasted. Temperatures are forecast to be around 15 degree above seasonal averages, full mixing could cause 20 to 25 degrees above normal readings. Confidence is low that areas will reach record levels, but it can not be fully ruled out. Here are a couple of records for Sunday:

Missoula: 60 set in 2020 Kalispell: 54 set in 1971 Butte: 57 set in 1934 Orofino area: 55 set in 2005

A weak cold front moves through the Northern Rockies Sunday night and Monday causing temperatures to drop, but will still remain above seasonal averages. Moisture will be fairly limited with this front so only light precipitation will fall across the Northern Rockies. Snow levels will drop to around 4000 feet by Monday morning allowing for the potential for a couple of inches of new snow in the mountains and mainly rain in the valleys. Even though the valleys experience rain a few road surfaces could be near to below freezing Monday morning allowing for patchy ice due to the cold sub-surface temperatures.

A strong ridge of high pressure is expected to develop over the region by mid next week. The temperatures will be steadily climbing each day in the higher terrain, but the valleys are anticipated to be dealing with inversions.

AVIATION

Light shower activity will continue to move through the region this afternoon and over night mainly over northwest Montana. This light precipitation has the potential to bring slightly reduced visibility to KGPI at times tonight. The threat for freezing rain is lower compared to yesterday due to valleys warming well above freezing today. Strong winds aloft are expected to move over the area tonight creating turbulence around ridge tops.

MSO WATCHES/WARNINGS/ADVISORIES

MT...None. ID...None.