Avalanche Advisory Archive Pre-2016

Date Issued:2012-02-17
Danger:2
Trend:2
Probability:2
Size:1
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...NUMEROUS RAIN AND SNOW SHOWERS IN THE MORNING...THEN
SCATTERED RAIN SHOWERS IN THE AFTERNOON. SNOW LEVEL RISING TO 800 FEET BY THE AFTERNOON. HIGHS AROUND 39. EAST WIND 10 MPH IN THE MORNING BECOMING LIGHT AND VARIABLE.

TONIGHT...MOSTLY CLOUDY. ISOLATED RAIN AND SNOW SHOWERS LATE. LOWS AROUND 29. NORTHWEST WIND 10 MPH IN THE EVENING BECOMING LIGHT AND VARIABLE.

SATURDAY...MOSTLY CLOUDY. SCATTERED SNOW SHOWERS BECOMING
SCATTERED RAIN SHOWERS IN THE AFTERNOON. HIGHS AROUND 36. LIGHT WINDS.

Temperatures yesterday stayed below freezing at the Mt Roberts Tram summit at about 30f, while the Eaglecrest summit was slightly cooler at around 27f.

The tram received another 12mm of precip and about another 12cm of new snow staying fairly light after what we had seen over the last 2 weeks. The day before we had 14mm of precip and only 12cm of snow that settled into 9cm. So overall in the last 48 hours at the tram summit we have 22cm (about 9\") of new snow in wind sheltered locations.

The Eaglecrest UAS site isnt receiving or reading nearly as much snow showing a 48hour total of about 11cm(just over 4\").

Winds were moderate during this 48 hour event from 10-25mph peaking at 35mph at the tram summit and 15-35mph peaking at over 45mph at Eaglecrest.

In general we have not had that much new snow. But this snow fell on a hard icy surface in places. Also we have had moderate to considerable windloading in places out of the SSE.

Avalanche danger is MODERATE at this time. Natural avalanches unlikely with the possible exception of small we slides as the snow cleans itself off of the steep rocks during the heat of the day. Potentially destructive avalanches unlikely to come near or reach developed areas.

Human triggered avalanches possible especially in windloaded pockets near summit and ridgeline in wind exposed locations on North to West facing slopes.

Slides should remains small should they occur. But be cautious of exposed locations and terrain traps.

Have a great day.

Tip:

Weak Interface:

Usually, avalanches fracture within a discrete weak layer but occasionally, the fracture can form along a thin boundary between two stronger layers. A common example is when a slab slides on an ice crust. Also see ?weak layer?.