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 Wednesday January 16, 2019 - 11:55 p.m.
*Winter Weather Advisory for Lincoln County from 11:00 a.m. Thursday through 5:00 p.m. Friday*
*Winter Weather Advisory for Sanders County from 5:00 a.m. Thursday through 5:00 p.m. Friday*
Wednesday night…Increasing clouds. A slight chance of snow showers after midnight across Sanders County. Lows in the 20s except locally mid teens across valleys of northern Lincoln County near the Canadian border with near 20 around 5000 feet. Local east to northeast winds 5 to 15 mph developing after midnight along the Kootenai River between Libby and Troy and along the Clark Fork River between Noxon and Heron. Ridge top winds becoming northeast 15 to 25 mph after midnight.
Thursday…Snow. Accumulations of 2 to 4 inches possible below 4000 feet with 4 to 8 inches possible above 4000 feet. Local accumulations of up to 6 inches possible below 4000 feet along and west of the Cabinet Mountains. Highs in the mid 20s to mid 30s with mid 20s around 5000 feet. Local east wind 5 to 15 mph decreasing in the afternoon. Ridge top winds east 15 to 25 mph decreasing to 10 to 20 mph in the afternoon. Areas of blowing and drifting snow across the higher elevations.
Thursday night...Snow likely. Patchy fog possible. Accumulations of 1 to 2 inches possible below 4000 feet with 2 to 4 inches possible above 4000 feet. Lows in the 20s to near 30 with lower 20s around 5000 feet. Light wind with ridge top winds becoming southwest 5 to 15 mph overnight.
Friday…Snow likely in the morning then mostly cloudy with a chance of rain and snow showers in the afternoon. Snow level rising to near 2500 to 3000 feet in the afternoon. Snow accumulations of 1 to 2 inches possible below 4000 feet with 3 to 6 inches possible above 4000 feet. Highs in the 30s with upper 20s around 5000 feet. Local south to southwest winds 5 to 15 mph in the afternoon with ridge top winds southwest 10 to 20 mph with gusts to 30 mph.
Extended Outlook (Saturday through Wednesday)
Saturday…A chance of rain and snow showers in the valleys with a chance of snow in the mountains. Lows in the upper 20s to mid 30s with mid 20s around 5000 feet. Highs in the mid 30s to lower 40s with upper 20s around 5000 feet.
Sunday…A chance of rain and snow showers south with a slight chance of rain and snow showers north. Lows in the upper 20s to lower 30s with mid 20s around 5000 feet. Highs in the 30s with temperatures holding steady in the mid 20s then falling in the afternoon around 5000 feet.
Monday through Wednesday…A chance of snow showers. Lows in the 20s with upper teens around 5000 feet. Highs in the upper 20s to mid 30s with lower 20s around 5000 feet.
In-Depth Weather Discussion for Northwest Montana/Rockies
Issued 01/15/2018 9:40 p.m.
Valley locations across Sanders County along the Clark Fork River cleared out fairly nicely once again on Tuesday although mid and high clouds filtered the sun by afternoon replacing the low clouds yet temperatures remained rather chilly. Low clouds managed to hang tough as expected further north across Lincoln County valleys. A weak system looks to move north overnight tonight into early Wednesday morning and will likely produce some flurries or light snow showers but nothing more than a skiff to a dusting looks possible at this time. Temperatures aloft will continue to cool with lowering heights and thicknesses which will continue to weaken valley inversions thus valley temperatures are likely to warm while slopes and ridges will likely cool. Most valley locations will also likely see some sunshine, if only for a brief period on Wednesday as low clouds will likely break up across Lincoln County to give partial afternoon clearing although mid and high clouds will once again increase from the south by late in the day as the next system begins to push in. Snow showers will slowly increase from south to north overnight on Wednesday with the most widespread and heaviest snowfall moving in on Thursday during the day. Latest models are beginning to show a bit more enhancement to the snowfall as the combination of a shortwave dropping southward from Canada east of the Continental Divide provides lift and forcing in northwest flow combines with lift and forcing from the southern system pushing up from the south combine across Northwest Montana and North Idaho. This may potentially produce a steady light to at times moderate snowfall across the region worthy of at least snow advisory criteria with my best guess at preliminary snowfalls of 2 to 4 inches across valley locations and possibly 4 to 8 inches across higher terrain. These numbers are just a first guess but could go up or down depending on how things actually come together. In any case, I am feeling more confident that some minor shoveling and plowing may be necessary on Thursday into Friday. Warmer air will eventually push into the region by Friday night into Saturday raising snow levels and possibly introducing a possibility of freezing rain early Saturday morning for valley locations before conditions warm up enough to switch precipitation over to plain rain or a rain/snow mix. Higher terrain may end up doing decent with snowfall totals over the 4 day period from Thursday through Sunday in the 10 to 20 inch range or perhaps a bit more. If enough cold air hangs on in the valleys then over that same 4 day period some valley locations such as Yaak and Trego may see totals in the 10 to 16 inch range as well although this may be a bit on the high side. Colder air looks to return region wide by Sunday night lowering snow levels back down to valley floors with unsettled conditions continuing into next week in northwest flow. Stay tuned and keep the shovels, plows and ice melt close by. It has not been much of a winter thus far and while I do not see any heavy or major snowfalls, there still may be some heavier snowfalls on the way so check back often.