Active weather is expected through the weekend as an upper-level trough slowly passes through our area. Tonight, we are going to have mostly cloudy skies with a few showers and isolated thunderstorms around before midnight and some scattered rain around after midnight, generally in western portions of north-central Montana and around/west of Helena. It is also going to be cool tonight as lows are going to be in the 40s in most spots.
Here is the detailed forecast:
Tomorrow, there will be a larger area of rain around during the morning that will be located around/to the west of a line from Helena to Havre to Great Falls. This area of rain will dissipate as we get closer to lunchtime. There will then be some scattered showers and isolated thunderstorms around during the afternoon and evening. We are also going to have mostly to partly cloudy skies tomorrow, with more sunshine in locations east of I-15.
Cooler temperatures are also expected tomorrow as highs are going to be in the mid to upper 50s and low to mid 60s in most spots (low to mid 70s in northeastern Montana). It is also going to be a little breezy tomorrow in eastern portions of north-central Montana and along the Rocky Mountain Front as sustained wind speeds are going to be between 5 and 20 mph.
On Saturday, there are going to be some scattered showers around, generally during the afternoon and evening, as a cold front begins to approach our area. There will also be some snow in the mountains on Saturday. There are then going to be some areas of rain and mountain snow around Saturday night and Sunday morning, especially in central Montana and in western portions of north-central Montana, as this cold front passes through our area. Snow levels will plummet down to ~4000-5000 feet Sunday morning, so some lower elevation locations, especially near the mountains and along the Rocky Mountain Front will see some snow fall. As we go through Sunday, the precipitation will gradually taper off from north to south. We are also going to have mostly cloudy skies on Saturday and decreasing clouds from north to south on Sunday.
Many of the mountain ranges in central and north-central Montana will see their first accumulating snowfall of the season this weekend. In Glacier National Park, over 6” of snow is possible above 7000 feet and 2-6” of snow is expected between 5500 and 7000 feet. Due to this snow, a WINTER STORM WATCH is in effect for the Glacier area from 12am until 12pm Sunday. This snow may cause the Going-to-the-Sun road to briefly close this weekend. Cold, wet, and raw conditions are also expected in Glacier National Park this weekend, so dress appropriately if you will be recreating outdoors.
In the mountains in central Montana, like the Little Belts and Big Belts, up to 6” of snow is possible. In the lower elevations, little (<1”) to no snow accumulation is expected. This snow may also create hazardous driving conditions over a few of the mountain passes Saturday night into Sunday morning.
Through Sunday evening, western portions of north-central Montana (west of a line from Havre to Lewistown) and the Helena area will likely receive between .25” and .75” of precipitation, with locally higher amounts possible. Eastern portions of north-central Montana will miss out on the beneficial moisture as most locations will receive less than .25” of rain.
A big cool-down is also expected this weekend. On Saturday, highs are going to be in the 50s and low to mid 60s and on Sunday highs are going to be in the 40s and low to mid 50s, which is well below average for this time of year. A widespread freeze is expected Sunday night as lows are going to be in the 20s and low 30s. It is also going to be a little breezy in some areas this weekend as sustained wind speeds are going to be between 5 and 20 mph.
An upper-level ridge will build back into our area early next week, providing us with lots of sunshine, dry conditions, and warming temperatures as highs are going to be in the mid to upper 50s and low 60s on Monday; the 60s on Tuesday; and the 70s and upper 60s on Wednesday.
