Archived

Avalanche Forecast

Mar 19th, 2018–Mar 20th, 2018

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Rockies.

Pay close attention to how the new snow is bonding to the old snow surfaces, and be extra vigilant for pockets of wind slab. Avalanche danger will increase rapidly on sunny slopes, if the sun makes an appearance on Tuesday.

Confidence

Low - Due to the number of field observations

Weather Forecast

We're in between storm systems for the next two days. More snow (up to 10cm) on Thursday. TUESDAY: Cloudy with sunny breaks and scattered flurries. Moderate westerly winds. Alpine temperature +2 C. Freezing level 1700 m.WEDNESDAY: Cloudy with sunny breaks and scattered flurries. Light to moderate westerly winds. Alpine temperature +3 C. Freezing level 1900 m.THURSDAY: Snow (5-10 cm). Moderate southerly winds. Alpine temperature +3 C. Freezing level 2000 m.

Avalanche Summary

Many dry loose avalanches to size 1.5 were reported on all alpine aspects on Monday.

Snowpack Summary

14-24 cm of low density snow fell Sunday overnight into Monday. This new snow sits on a wide variety of old surfaces: a melt-freeze crust on sunny aspects, some old wind slabs in the alpine near ridge crests and predominantly dry snow or surface hoar (up to 20mm in size) on north aspects above 1500-1800m.A weak layer of surface hoar buried mid-February exists in parts of the region around 50 to 80 cm deep. The lower snowpack is weak with a combination of crusts and facets near the bottom of the snowpack that are widespread.

Avalanche Problems

Storm Slabs

Watch for signs of poor bonding of the new snow with underlying surfaces, especially the March 18th crust, which can be found almost everywhere except high north facing aspects. Dry loose sluffs may run fast and far on slippery crusts.

Watch for localized areas of deeper snow accumulation, particularly on south /east slopes.Observe for signs of instability, such as cracking, whumpfing, and avalanche activity.Use caution in lee areas in the alpine and tree line, especially south / west facing slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Loose Wet

If the sun comes out on Tuesday, expect the new snow to become reactive and/or slide naturally.

Avoid exposure to sunny slopesBe cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.Watch for signs that the snow is moistening such as pin-wheeling and point-releases below cliffs.

Aspects: North, North East, East, South East.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 2.5