Before we start the forecasts, let’s look at the past 48-hour (Tuesday – Thursday AM) accumulations:  

•    12” – Big Sky Resort 
•    12” – Lost Trail Pass
•    11” – Bridger Bowl
•    11” – Ski Discovery 
•     8” – Great Divide 
•     8” – Lookout Pass
•     8” – Montana Snowbowl
•     5” – Showdown
•     4” – Maverick Mountain   
•     4” – Teton Pass Ski Area
•     2” – Blacktail Mountain
•     2” – Whitefish Mountain Resort
•     2” – Turner Mountain      
•     1” – Red Lodge Mountain   

West of the Continental Divide:

Below: A bluebird Thursday morning at Whitefish. 

Thursday - Friday: A surface ridge of high-pressure will build into the region on Thursday and amplify on Friday. Skies will be a mix of sun and clouds both days. Temps will not warm all that much but will stay at seasonal levels. Light winds both days. 

Saturday & Sunday: A slight weakening of the high-pressure will allow a bit more cloud cover but overall ‘mostly sunny’ skies will be experienced this weekend. By the mid to late afternoon on Sunday, look for clouds to be on the increase as the high-pressure ridge begins to flatten. Mountain top afternoon high temps will be right around 30 – 32F both days. Light SW winds.  

Monday: As a Pacific storm system approaches the Oregon Coast early on Monday, it will send weak waves of moisture towards the Northern Rockies via a SW flow aloft. This storm looks to track south through the Great Basin but some snow showers with light accumulations (trace to 2”) are slightly possible for areas along and south of I-90. Slightly cooler on Monday. Light but gusty E/SE winds possible. 

East of the Continental Divide: 

Below: A 'white capped' Lone Mountain at Big Sky where they have received a foot of fresh pow in the last 24-hours. Look for clearing skies into Thursday afternoon. 

Thursday & Friday: Instability behind the exiting cold-front/storm system Thursday morning will bring a few isolated snow showers across the Big Belts and the Madison’s with trace amounts slightly possible at Showdown and Big Sky. Otherwise, a ridge of high-pressure will begin to build over the Northern Rockies bringing partial clearing through the day on Thursday. Skies will be a mix of sun and clouds. Much colder, with afternoon high temps at 8000’ 15F – 20F. Light north winds. The ridge will amplify on Friday bringing a widespread sunny day across the region with slightly warmer surface temps at 8000’ of 23F – 25F. Light N/NE winds.  

Saturday & Sunday: Surface ridge of high-pressure continues across the Northern Rockies but look for a few more clouds in the mix. Generally, partly sunny skies on both days. Temps continue to rise a few degrees but stay just below seasonal averages with 8000’ high temps 26F – 28F. Light SW winds. 

Monday: As a SW flow ushers in a trough of low pressure on Monday it will push the dominant ridge of high-pressure into the Canadian Prairies. Monday looks to be a transitional day with mostly cloudy skies and isolated snow showers. Light accumulations, generally around one inch are possible. Light and variable S/SE winds. 

A trough of low-pressure could allow a few weak impulses to eject northward from a large storm system moving through the Great Basin and Central Rockies. While there are widespread disagreement in our weather models on the tracking and strengths of these disturbances, the best chances for accumulating snow (Tues 3/21 – Fri 3/24) lie across the southern tier of the Treasure State where Big Sky and Red Lodge look well positioned. Stay tuned. 

Below: The Euro Deterministic forecast map of the Lower 48' shows the departing storm system that dropped up to a foot of snow across SW Montana's mountains moving eastward and developing into a large storm as it progresses towards New England. A ridge of high -pressure resides over the Northern Rockies until Sunday 3/19 before an incoming trough arrives Monday 3/20 and brings unsettled skies through next week.

 

Thanks for tuning in. Next update on Saturday PM 3/18.  

Powder Out – 

Bob