Avalanche Advisory Archive Pre-2016

Date Issued:2013-02-28
Danger:3
Trend:3
Probability:4
Size:3
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...RAIN. SNOW LEVEL 1100 FEET IN THE MORNING. HIGHS AROUND 40. SOUTHEAST WIND 15 TO 25 MPH DIMINISHING TO 5 TO 15 MPH IN THE AFTERNOON.

TONIGHT...RAIN LIKELY. SNOW LEVEL 1100 FEET. LOWS AROUND 35.
SOUTHEAST WIND 5 TO 15 MPH.

FRIDAY...RAIN AND SNOW IN THE MORNING. RAIN IN THE AFTERNOON.
NO SNOW ACCUMULATION. SNOW LEVEL RISING TO 700 FEET IN THE
AFTERNOON. HIGHS AROUND 39. SOUTHEAST WIND 10 MPH.

We have received 19mm of precip in the last 48 hours which left 15cm of new snow after settlement and consolidation are taken into consideration.

Winds have been considerable to high over the last two days with a couple of directional changes. Two days ago we received a fair amount of loading with winds out of the NE. Last night winds ramped up to 40+ across the region out of the SE. Many of the slopes in our region are windloaded today.

Temperatures warmed up by 3C degrees at Eaglecrest over the last 48 hours and the tram stayed close to the same coming up close to the freezing point a few times over the last 48 hours.

Temperatures today are forecast to rise slightly as is the freezing level. This afternoon we are supposed to see around 1/3\" of precip in a 6 hour period during the height of this warming.

Avalanche danger is CONSIDERABLE today. Natural Avalanches are possible and human triggered avalanches are probable in places. Danger is heightened in wind loaded locations.

Avoid the Flume Trail today. Avoid spending time in the avalanche paths along Thane Road.

Tip:

Loading-

The addition of weight on top of a snowpack, usually from precipitation, wind drifting, or a person.

Loading from Wind:

As we know, snow does not like rapid changes, especially a rapid increase in weight piled on top of a buried weak layer. By far, the quickest way to load snow onto a slope is from wind drifting. Wind can deposit snow ten times more rapidly than snow falling out of the sky.

Wind erodes snow from the windward (upwind) side of an obstacle and deposits snow on the leeward (downwind) side. Deposited snow looks smooth and rounded. You should always beware of recent deposits of wind drifted snow on steep slopes.

Loading from Snow or Rain:

The second fastest way to load a buried weak layer is through new snow or rain. Rapidly-added weight almost always means rapidly-rising avalanche danger. Remember that more precipitation usually falls at higher elevations than lower elevations and more on the windward sides of mountain ranges than the leeward sides (with the exception of wind drifting near the ridges).