Canadian Rockies Daily Snow
By Bob Ambrose, Forecaster Posted 2 months ago December 5, 2023
A deep trough in the Gulf of Alaska will spin down the BC coast, and then inland drawing sub-tropical moisture, aka an Atmosphere River, into the Rockies. Snow levels begin to rise Tues, up to 2600m across the South Rockies, but generally staying around 2000m for the SkiBig3 resorts. A cold front arrives Weds PM normalizing snow levels with another batch of snow lasting into Thurs.
Short Term Forecast
24-hour snowfall as of Tuesday morning at 0700:
- 12cm Lake Louise
- 8cm Banff/Sunshine Village (BSV)
- 10cm Marmot Basin
Castle Mountain opened for the season this past Saturday and the locals were stoked. The Huckleberry and Green Chairs are currently open. (image courtesy of Castle Mtn Facebook)
Tuesday, December 5 – Thursday, December 7
As the Gulf of Alaska trough works its way south along the BC coast a moist SW flow, or sub-tropical Atmospheric River will deliver the next round. Periods of light snowfall on Tuesday will increase to moderate to possibly heavy snowfall rates late Tuesday afternoon through Tuesday night. Snow levels rise to around 2000m, but the south Rockies will tap into warmer air with snow levels rising to 2600m through the morning. Gusty SW winds in the 40-50 kph range will be felt on the ridge tops. Especially stormy along the Divide. Additional accumulations from Tuesday through Wednesday morning of 10 – 20cm are likely at BSV and Louise, with 3 – 6cm at Norquay and Marmot. Castle, and perhaps Nakiska will unfortunately see mostly rain.
Here's the GOES West Satellite at 7:30 Tuesday. A pretty impressive, and unseasonably warm flow that originated near the Hawaiian Islands will plow into the Canadian Rockies Tuesday and Tuesday night.
The sub-tropical storm wanes on Wednesday to isolated flurries, with additional accumulations of 3 – 5cm likely above 1900m for most resorts (except Castle, as they will have rain showers up to 2400m). SW winds also die down to 10 – 20 kph, with 20 – 40 kph at Nakiska and Castle.
The active SW flow and favorable upper-level jet stream dynamics will interact with colder air on Wednesday night plunging snow levels back down to valley floors by Thursday morning. This could be the most productive time for low-density snowfall, with models leaning in the 10 – 20cm range for the mountains BSV north to Lake Louise through 4 PM Thursday. Nakiska and points south to Castle Mountain could see 5 – 15cm, with 4 – 8cm at Marmot Basin. 2000m high temps around -7C Thursday.
Friday, December 8 – Saturday, December 9
A dry-out looks in store for Friday and Saturday as colder air settles into the Rockies under a building ridge. The skies will be mostly cloudy with isolated sunny spells. Alpine high temps at 2000m will be around -10C Friday, and -13C on Saturday. Light W/NW winds on both days.
Models move a weak system that will be tracking through southern BC into the South Rockies Saturday night into Sunday. A 20% chance of light accumulations at Castle Mountain and PPK in the Saturday night/Sunday time frame.
Another weak system is portrayed for the Monday/Tuesday 12/11 and 12/12 time period. The flux factor is still in this extended forecast, so expect these forecasts will be fine-tuned in the coming days. At least it looks active and I do think surface temps will be trending colder starting Sunday into early next week. Kudos for the snow dances – keep em’ going! (image, courtesy of Castle Mountain/Facebook page)
Next report, Thursday, December 7.
Alberta Rockies Ski Resorts & Areas with Opening Dates / North & South Regions are solely for Geographic References.
North Region: ( * denotes SkiBig3 resorts )
*Mt Norquay OPEN
Marmot Basin OPEN
Castle Mountain December 1st
Fortress / KPOW Cat Skiing OPEN for booking
Pass Powderkeg December 1 (then weekends only)
Latest Avalanche Conditions:
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