... STRONG WIND FROM THIS AFTERNOON THROUGH TONIGHT ...

TODAY ... SUNNY. BECOMING LOCALLY WINDY. HIGHS AROUND 28.
NORTHEAST WIND INCREASING TO 10 TO 20 MPH. GUSTS TO AROUND 40 MPH IN THE AFTERNOON NEAR DOWNTOWN JUNEAU AND DOUGLAS.

TONIGHT ... CLEAR ... LOCALLY WINDY. LOWS 10 TO 23 ... EXCEPT AROUND 3 ABOVE IN WIND SHELTERED AREAS. NORTHEAST WIND 15 TO 30 MPH. GUSTS TO AROUND 45 MPH FOR DOWNTOWN JUNEAU AND DOUGLAS.

SUNDAY ... SUNNY. HIGHS AROUND 28. NORTHEAST WIND 15 TO 25 MPH.
STRONGEST NEAR LYNN CANAL AND DOWNTOWN JUNEAU.

Yesterday saw no new snow accumulation, and the cloudy skies and light winds didn't create much change in the snowpack.

Winds changed direction and started picking up a little bit after midnight at both Eagelcrest and the Tram, but are still relatively light yet. As they increase during the day and we start to see significant wind transport of surface snow, hazard will be increasing.

This is the kind of weather that typically top-loads our urban slide paths.

Due to the small size of our snowpack I don't expect avalanche sizes to be large enough to damage buildings or reach Thane Rd, but it is definitely a good idea to stay off the Flume and Perseverance trails this afternoon.

The Hazard is CONSIDERABLE today. Natural avalanches are possible, but not likely to impact the urban zones outside of the Flume/Perseverance. Human triggered avalanches are likely on wind loaded slopes (S - SW - W), and possible on any slopes above 2000ft with the crust facet combo just above the big Melt-Freeze layer. There have already been multiple slides triggered on this layer over several days all around Douglas.

WEAK LAYER:

Once snow is done falling out of the sky it exists on the ground as layers. Some layers are relatively more cohesive (stronger layers) and others are relatively less cohesive (weaker layers).

Like cliffs in the Grand Canyon, if you brush a snowpit wall with your mitten, the weaker layers erode away while the stronger layers stick out. When the snowpack is stressed by rapid changes (e.g. wind-drifted snow, new snow, or rain) this stress can cause the weak layer to fracture.

Understandably, most avalanche geeks are obsessed by weak layers. Weak layers involved in most continental avalanche accidents usually are a ?persistent? grain type such as faceted snow, surface hoar or depth hoar, but in our Maritime snowpack it is often a layer formed within new snow such as low density new snow or graupel.

Today we see both types of weak layers in play in our snowpack.

After an avalanche occurs, you often hear avalanche professionals ask, ?what was the weak layer? or ?what did it run on?? The life of an avalanche aficionado revolves around knowing what is the weakest layer in the snowpack and how much stress it takes to make it fail.