Northwest Montana Regional Forecast

Includes Lincoln and Sanders Counties (cities of Libby, Troy, Eureka, Yaak, Bull Lake, Noxon, Heron, Trout Creek, Thompson Falls, and The Cabinet Mountains)

Issued Tuesday November 20, 2018 - 10:30 p.m.

Tuesday night...Fair skies in the evening then areas of freezing fog and low clouds developing in the valleys after midnight. Lows in the teens to lower 20s except locally single digits in colder valleys with near 30 around 5000 feet. Light wind except winds becoming south 5 to 15 mph across ridges after midnight.

Wednesday…Areas of freezing fog and low clouds in the valleys until early afternoon otherwise increasing high clouds. Highs in the upper 30s to mid 40s with upper 30s around 5000 feet. Afternoon south winds 5 to 15 mph with ridge top winds southwest 10 to 20 mph with gusts to 30 mph.

Wednesday night...Mostly cloudy with a chance of rain and snow showers. Snow level near 3500 to 4000 feet. Snow accumulations of up to 1 inch possible above 4000 feet. Lows in the upper 20s to mid 30s with upper 20s around 5000 feet. Light south wind except ridge top winds southwest 10 to 15 mph.

Thanksgiving Day...Mostly cloudy with rain and snow likely west of Lake Koocanusa and the Fisher River with a chance of rain and snow showers from Lake Koocanusa and the Fisher River east. Snow level 3000 feet. Snow accumulations of 1 to 2 inches possible above 3500 feet. Highs in the upper 30s to mid 40s with near 30 around 5000 feet. Southwest winds 5 to 15 mph with ridge top winds southwest 10 to 20 mph.


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Extended Outlook(Friday through Tuesday)

Friday…Locally breezy and cooler with a chance of rain and snow showers. Lows in the upper 20s to mid 30s with mid 20s around 5000 feet. Highs in the 30s to near 40 with upper 20s around 5000 feet.

Saturday…Dry except for a slight chance of mainly mountain snow showers. Lows in the 20s with lower 20s around 5000 feet. Highs in the 30s with mid 20s around 5000 feet.

Sunday and Monday…A chance of snow showers. Lows in the 20s with lower 20s around 5000 feet. Highs in the 30s with mid to upper 20s around 5000 feet.

Tuesday…A chance of rain and snow showers. Lows in the mid 20s to mid 30s with mid 20s around 5000 feet. Highs in the mid 30s to lower 40s with near 30 around 5000 feet.


In-Depth Weather Discussion for Northwest Montana/Rockies

Issued 11/20/2018 10:45 p.m.

Valley freezing fog and low clouds were a bit more widespread again Tuesday morning and that trend will likely continue into Wednesday with most valleys likely to wake up to the low overcast or fog. A bit more mixing is likely in the afternoon on Wednesday now with valley stratus and fog likely to break up in the afternoon as southerly winds aloft may be able to mix down into the valleys and break the inversion allowing for a potential significant warm up into the 40s if southerly winds can mix to the surface. Clouds will be on the increase during the day on Wednesday for areas not affected by the low clouds and fog but any precipitation will likely hold off until Wednesday night. First system will weaken considerably as it moves through our region on Wednesday night into Thanksgiving Day with the best chances of precipitation likely in the western parts of both Lincoln and Sanders Counties mainly along and west of the Fisher River and Lake Koocanusa or if in Sanders County along and south and west of the Cabinet Mountains. Snow levels will be near 3500 feet but very little accumulation is likely from this first system with perhaps an inch or two above 4000 feet. The next stronger shortwave will be following quickly on the heels of the first moving in during the day on Friday. This system has consistently been shown in the models as having a stronger surface low associated with it but it now appears that the surface low may track a bit further south across southern Lincoln County or northern Sanders County. If this holds true then areas near the Canadian border will likely not see as much precipitation or as strong of winds. Snow levels will also be much lower closer to valley floors except for central and southern Sanders County where they would remain near 3000 to 3500 feet until early evening when they would fall to valley floors. This system may produce some moderate snow accumulations to the mountains with preliminary snowfall totals of perhaps 5 to 10 inches above 5000 feet with possibly 2 to 4 inches of snow in the lower elevations including many valley areas such as Bull Lake, Troy, Libby, Heron and Happys Inn. Northern areas such as Eureka, Rexford and Yaak may not see much in the way of snowfall if the southern surface low solution comes to pass but we will see. Weak shortwave ridge will move in for Saturday bringing more stable conditions with just a couple of mountain snow showers likely then another weak shortwave looks to move in for Sunday into Monday. This system also looks cold enough for snow levels to be near all valley floors. Active pattern looks like it may continue with another more mild system coming in on Tuesday with rising snow levels. In all of this there still does not appear to be any significant storms that would help to boost our snowpack yet every little bit will definitely help. If traveling for Thanksgiving or general travel conditions look generally good on Wednesday and on Saturday with Friday and Sunday looking like the poorest travel days due to weather. Stay tuned.