Below: The NBM 2.5 for snowfall Thursday through 6AM Monday April 3rd portrays a snowy next 4 days. 

West of the Continental Divide: 

Thursday: Winter Weather Advisories in effect through Thursday night for Lost Trail Pass and the Butte/Blackfoot region (Discovery). A large storm system off the West Coast has moved into California sending shortwave systems into the region. One such shortwave has moved just south of Lost Trail Pass Thursday morning. This system will slowly move NE through the day bringing periods of moderate snowfall to best positioned areas Lost Trail and Discovery, where another 3 – 5” will fall. Snowbowl could see another 1 – 3”. Snowfall will only affect areas along and south of the I-90 corridor. Whitefish, seemingly in a dry donut hole recently, will ride north of the storm track seeing mainly clouds with some sunny spells. Thursday night, residual snow showers from the exiting shortwave add another 1 – 3” at LT and Disco. High temps Thursday at area mountain tops in the low 30’s. Light NE winds.

Friday & Saturday: Clouds and gusty SW winds will be on the increase on Friday as our next storm system approaches the region out of the NW. Look for snow showers to develop at Lookout and Lost Trail passes on Friday (trace to 1”) but generally a mostly cloudy unsettled day with isolated snow showers across the region. SW winds with gusts to 30 mph on ridgetops by the afternoon. A deep trough of low-pressure with origins in the Gulf of Alaska will begin to spread through the region on Saturday bringing colder temps along with off and on periods of light snow lasting into Sunday. This system will move into NW Montana (Lookout, Blacktail, Whitefish) during the early morning hours Saturday and spread through the rest of the region by late afternoon/evening. Currently, Lookout Pass looks best positioned for storm totals (thru Saturday night) of 6 – 12”, with 2 – 5” at Whitefish, Snowbowl, and Lost Trail, with 1 -2” at Blacktail and Disco. Cooler than average temps both days with upper mountain high temps 24 – 28F. Gusty SW winds continue Saturday with ridgetop gusts to 40 mph. 

Sunday & Monday: Cloudy skies and lingering snow showers, along with much cooler temps in the wake of the departing cold front look in store for Sunday. The areas on the Idaho border, LT and Lookout, could see another inch or two during Sunday morning. Mountain top high temps on Sunday in the low to mid 20’s. Light to moderate west winds. Monday looks to offer up a mix of sun and clouds with continued cooler than average temps. 

East of the Continental Divide: 

Thursday: An organized shortwave low will move through SW and North Central Montana on Thursday bringing widespread periods of light snowfall through the day and into Thursday night. The heaviest amounts look to fall at Big Sky where 4” has already fallen, with another 3 – 5” likely through Thursday night. Bridger will likely add another 2 – 4” to the 2” already received. Great Divide and Showdown will also get in on the action with 2 – 5” possible through Thursday night. Red Lodge, snow will begin Thursday afternoon continuing overnight with 1 – 3”.  Highs in the mid to upper 20’s at 8000’. Variable light winds.

Friday & Saturday: Generally, a mostly cloudy dry day on Friday across the region as a short-lived ridge builds in. That said, late afternoon and evening snow showers across the southern tier of the region at Big Sky on Friday could add another 1 – 2”. Cloudy skies on Saturday morning will give way to snow showers, along with gusty SW winds Saturday afternoon as a trough of Alaskan low-pressure and associated cold front spreads through the region. SW and North Central areas once again look to be favored with snowfall Saturday late afternoon continuing into the overnight hours. Big Sky, Bridger, and Showdown look best positioned for storm totals (thru 9AM Sunday morning) of 2 – 5”, with trace amounts to an inch elsewhere. Highs in the mid to upper 20’s at 8000’ both days. Moderate to high SW winds, with ridgetop gusts to 45 mph likely Saturday afternoon at Big Sky.  

Sunday & Monday: Lingering snow showers persist through Sunday as instability related to the passing cold front brings chances of an additional 1 – 2” at Big Sky and Red Lodge. Elsewhere, general clearing with a mix of mostly cloudy skies with some sunny spells. Much cooler temps in the wake of the cold front on Sunday, with highs at 8000’ in the upper teens. Monday looks to offer up a mix of sun and clouds with clouds increasing and snow showers developing during the afternoon and into the overnight hours across the SW at Big Sky and Bridger. Light accumulations possible.  Continued much cooler than average temps. 

Tuesday, April 4th  – Friday, April 7th 

A trough of low-pressure will be present over the Northern Rockies allowing weak Pacific disturbances to flow into mainly SW Montana Tuesday and Wednesday keeping the skies unsettled with daily light accumulating snowfall likely for areas along and south of the I-90 corridor across the state. We’re watching another wildcard upslope storm for Red Lodge on Tuesday that could bring deep totals up to 20”.  Cooler than average temps through Wednesday. High-pressure looks to build in on Thursday and Friday bringing dry skies and a warm up to seasonal norms. Stay tuned.  

Below: Latest month end March Snowpack numbers (% of average) by river basins across the Treasure State reflect the South/SW track of storms since the first week of January. 

Thanks for tuning in. Next update on Saturday 4/1.  

Powder Out – 

Bob