Avalanche Forecast

A frontal system passing through Sunday afternoon and evening should produce generally light to moderate amounts of new precipitation at moderate snow levels with minor wind transport.  Another warm front should lift through the area Monday afternoon but with light rain and snow expected.

Snow levels should continue to creep up overnight and through Monday...extending the reach for wet loose avalanches into the near treeline zone on all aspects with light rain saturating the most recent storm snow potentially up to 5500 feet Monday. Watch for heavier surface snow that begins to naturally pinwheel on steeper slopes.  Wet-loose avalanches may start small but entrain large amounts of snow.  Avoid terrain traps and steep slopes and watch for signs of natural wet loose activity.   

Cornices have grown large over the last 2 weeks. A cornice failure could provide a large enough load to trigger a destructive avalanche. With the warming Monday...rising temperatures and rain should cause cornices to become even more sensitive and likely to fail.  

Continue your careful snow pack evaluation and cautious terrain selections during the work week.

Recent Northwest Weather

An extended mild and dry period occurred the latter half of January generally forming a crust in all areas. Very cold weather followed in early February which produced light low density snowfall, near surface faceting, and faceting near and just above the crust.

Frontal systems over the weekend were weaker than the frequent systems seen over the past 2 weeks.  Until we have an extended break in the storm cycle...the running tally for water equivalent over the past 13 days is about 8-10 inches with snowfall about 6 - 7 feet at the NWAC weather station at Hurricane Ridge and the Waterhole Snotel.

Observations for Hurricane Ridge area

Several avalanche cycles have occurred over the last 2 weeks. The last natural cycle likely occurred during the middle of last week when the road to Hurricane Ridge was closed. NPS employees found avalanche debris up to 8' deep just off the Hurricane Ridge road at 3600 ft while plowing Thursday. The start zone was likely in the near-treeline zone on a S-SE aspect. 

The late January crust layer and associated weak layers are now deeply buried by all the new storm snow, but still producing areas of collapsing and large whumpfing as reported in a NE meadow below treeline by a frequent TAY-er in the Hurricane Ridge area. The same skier had pictures of some very large cornice collapses.

On Friday NWAC observer Katy Reid Friday found stubborn but still possible to ski trigger wind slab on northerly aspects above treeline. She also observed quickly releasing wet loose avalanches on below treeline on solar aspects reacting to the strengthening February sunshine. Finally, new surface hoar around 4mm thick formed on all wind and sun sheltered aspects near and below treeline and may have been buried by the light new snow with little wind Saturday.  If buried intact...this layer could become an active interface with shallow new storm snow slab becoming denser Monday. 

Road side roller balls and small wet loose on solar slopes at Hurricane on Friday by Katy Reid.

The mid and base pack at Hurricane should still consist of mostly stable crusts and melt form layers from periods of warm weather earlier this winter.