TODAY...RAIN. SNOW LEVEL 100 FEET RISING TO 1400 FEET IN THE AFTERNOON. HIGHS AROUND 40. SOUTHEAST WIND 10 MPH.

TONIGHT...RAIN. SNOW LEVEL LOWERING TO 900 FEET. LOWS AROUND 35. SOUTHEAST WIND 5 TO 15 MPH.

FRIDAY...RAIN...MIXED WITH SNOW IN THE MORNING. NO ACCUMULATION. HIGHS AROUND 40. SOUTHEAST WIND 10 MPH.

In the past 24 hours we received a trace of new precipitation at the Tram. We have seen a gradual cooling trend over the past 24 hours. We are below freezing at the Tram, Mt. Juneau and Eaglecrest this morning.

Yesterday, precipitation diminished and we even had some sunny breaks for most locations. Areas such as Mt. Juneau appeared to receive moderate incoming solar radiation where as locations such as Mt. Roberts stayed in the clouds until much later in the day. Areas that received ample sunshine yesterday probably formed a sun crust yesterday, which will bond differently than shaded areas as new precipitation starts falling later today.

The main avalanche problems today are wind slabs and wind loading. Winds have been steadily increasing overnight at all stations. Winds have been averaging around 20kts from the east/southeast since midnight at both the Tram and Eaglecrest. East/Southeast winds tend to cross load areas such as Thane Rd and Gold Creek. With new snow available for transport I expect to see wind loading in the Thane Rd and Gold Creek slide paths. I expect the wind slabs to be sensitive to artificial triggers but not pose a threat to developed structures. There will likely be isolated wind pockets that may release throughout the day.

Light precipitation has started falling this morning and another 0.4? of precipitation is forecasted in the next 24 hours. This will give the snow pack some time to settle and bond. Settlement and boding will help increase the strength of the snow pack over time. The persistent facet layer observed last week is not consistent enough to cause widespread slides in the Urban paths though it remains a hazard in the Douglas Alps.

Avalanche hazard is MODERATE today: Natural avalanches unlikely; human-triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas. Be increasingly cautious in or under steeper terrain and in avalanche zones.

Today is a good day to use caution when entering Flume/Perseverance trail and avoid being under Thane Rd as a pedestrian.

For backcountry travelers dangerous avalanche conditions exist. Careful snow pack evaluation, cautious route-finding and conservative decision-making are essential. Human triggered slides are likely within the new storm snow as well as wind loaded pockets. It is also possible that a small slab release within the storm snow could step down into the persistent facet layer causing a larger avalanche.

Today?s avalanche tip deals with wind slabs. Here is a definition of a wind slab from the Canadian Avalanche Center?s website;

?Wind slab avalanches are caused by a cohesive slab of wind-deposited snow overloading the bond to an underlying weak layer or interface. Wind slabs consist of snow crystals broken into small particles and packed together by the wind. These wind-deposits, often referred to as ?pillows,? are usually smooth and rounded and sometimes sound hollow. The moving snow as well as the debris can include hard and soft chunks of slab. Wind slabs are created on leeward (downwind) slopes and in cross-winded areas where the winds blow across the terrain. They are commonly found behind and below features that act as a natural wind-fence, such as bands or isolated stands of trees, ridges, ribs, etc.

Wind slabs can often be recognized by the pillowed shape of the deposited snow, sometimes a dull texture to the snow surface, a cohesive feel to the snow, an upside-down feel, or sometimes a hollow drum-like feel or sound.

For wind slabs to form there must be snow falling during the wind event or there must be loose surface snow available for transport. The extent of the wind slab formation depends on the speed of the wind, the duration of the wind event, and the amount of snow available for transport. Minor wind events may form wind slabs only in the immediate leeward of exposed ridge tops. As wind intensity increases, wind slabs will form well below ridge top, and leeward of cross-loading features such as ribs and gullies on slopes oriented parallel to the wind direction. Major wind events will form widespread wind slabs in all open areas and occasionally even in normally wind protected areas (such as open glades below treeline).?

The Forest Service National Avalanche center also has a great description of how a wind slab forms. It can be found at http://www.fsavalanche.org/encyclopedia/wind_slab.htm