A WINTER STORM WARNING is in effect for locations above 5000 feet in Cascade County, Jefferson County, Judith Basin County, central and southern Lewis and Clark County, and Meagher County from 6pm Thursday until 12am Saturday. 6 to 10 inches of snow accumulation is possible at pass level.
A WINTER WEATHER ADVISORY is in effect for the Rocky Mountain Front and southwestern Montana from 6pm Thursday until 6pm Friday. 2 to 6 inches of snow accumulation is possible.
There are going to be some scattered rain and mountain snow showers around tonight, generally in locations east of I-15, as a disturbance passes through our area. A few isolated thunderstorms are also possible before midnight. We are also going to have partly cloudy skies and cool/chilly temperatures tonight as lows are going to range from the upper 20s to the low 40s.
For tomorrow, we are going to have increasing clouds with some scattered evening rain and mountain snow showers around, generally in locations south of Great Falls, as a storm system begins to approach our area. A few isolated thunderstorms are also possible tomorrow evening. Precipitation is then going to become more widespread in coverage Thursday night. Precipitation is then likely on Friday, especially in locations south of the Hi-Line. For Thursday night and Friday, the precipitation is primarily going to be in the form of rain in the lower elevations, but some lower elevation locations, including Great Falls and Helena, may see some snow or a rain/snow mix late Thursday night and Friday morning. In the mountains, all snow is expected Thursday night and Friday.
Between Thursday evening and Saturday morning, 2 to 6 inches of snow accumulation is possible along the Rocky Mountain Front; over 6 inches of snow accumulation is possible in the mountains (above 5000 feet) in central Montana; and little to no snow accumulation is expected in most other locations, although a few spots may receive light snow accumulations of a couple inches. Now in terms of precipitation between Thursday evening and Saturday morning, up to 0.25” of precipitation is possible along the Hi-Line, but most locations are going to receive less than 0.1” of precipitation. In the mountains in central Montana and in the northerly upslope regions of these mountains, including Great Falls, 0.75” to 2” of precipitation is expected. In the valleys and in all other locations, generally 0.25” to 0.75” of precipitation is expected.
The temperatures are also going to cool down a lot between Thursday and Friday as highs on Thursday are going to be in the mid to upper 50s and low to mid 60s, and highs on Friday are going to be in the 40s. It is also going to be a bit breezy on Friday as sustained wind speeds are going to be between 10 and 20 mph.
Partly cloudy skies and mostly dry conditions are then expected on Saturday as high pressure is briefly going to be in control of our weather. We are then going to have mostly cloudy skies with some isolated rain and mountain snow showers around on Sunday as a disturbance passes through our area. It is also going to be cool this weekend as highs are going to be in the 50s. There is also going to be a little bit of a breeze around on Sunday as sustained wind speeds are going to be between 5 and 15 mph.
There are then going to be scattered rain and snow showers around Monday and Tuesday, generally from Monday afternoon through Tuesday morning, as another storm system passes through our area. There is also going to be a bit of a breeze around on Monday and Tuesday as sustained wind speeds are going to be between 10 and 20 mph. The temperatures are also going to cool down some over these two days as highs on Monday are going to be in the mid to upper 50s and low 60s, and highs on Tuesday are going to be in the upper 40s and low to mid 50s.
We are then going to have partly cloudy skies, dry conditions, and warmer temperatures on Wednesday as highs are going to be in the upper 50s and low to mid 60s.
