Avalog Join
Archived

Avalanche Forecast

Mar 12th, 2013–Mar 13th, 2013
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
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

Regions: South Rockies.

Warm temperatures and heavy precipitation are increasing the avalanche danger in the days to come. Good time to avoid avalanche terrain or to make very conservative terrain choices out there.

Confidence

Fair - Forecast snowfall amounts are uncertain for the entire period

Weather Forecast

Tuesday night and Wednesday: The strong Westerly flow bringing significant precipitation amounts into the interior should taper off a little tonight but should keep delivering moisture until Friday. Amounts could be around 20 mm in water equivalent till tomorrow evening. with winds blowing strong from the W. Freezing levels are expected to rise to close to 2000 m. during the day and stay high until Friday.Thursday: Similar amount of precipitation and freezing level is expected for Thursday with strong winds switching from the SW.Friday: The Westerly flow is forecasted to weaken and precipitation to taper off. Freezing levels and wind speeds should also start to drop.

Avalanche Summary

More and larger avalanches are expected with the forecasted warm and heavy precipitation in the days to come.

Snowpack Summary

Currently, 10 cm of new snow overlies a variety of surfaces; hard wind slabs lee of N, SW and W winds in alpine and treeline features, a well developed surface hoar in shaded areas above 1700 m., a melt-freeze crust below that elevation and a 3 cm sun crust on solar aspects at all elevations. The forecasted precipitation and warm temperatures will add a good load to the snowpack (could be another 20 mm in water equivalent till tomorrow night). The variety of surfaces described earlier will most likely be reactive to this new load and create a good failure plane for avalanches to slide on. With freezing levels rising again tomorrow, the new dryer snow layer at the upper below treeline and treeline elevation band (between ~1500 m. and ~2000 m.). could get soaked and create wetslabs and loose wet avalanches.

Avalanche Problems

Storm Slabs

Heavy precipitation and warm temperatures are expected in the days to come creating new storm slabs, new wind slabs lee of strong SW winds in the alpine and treeline and adding significant load on the underlying layers.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid exposure to overhead avalanche terrain, as large avalanches may reach runout zones.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1 - 6