Northwest Weather and Avalanche Center Seattle Washington
1436 PM PDT Wed Jun 09 2010
Please note that regularly scheduled avalanche forecasts for the past winter season have ended. However weather and snow conditions are continuing to be monitored at the Northwest Weather and Avalanche Center with the information that remains available, and special statements are issued when unusually severe avalanche conditions develop.
Please note that NWAC forecasts normally apply to elevations below 7000 feet outside of operating ski areas and highways. However, owing to the recent avalanche accident on Mt Rainier, some additional snowpack information at higher elevations, and the unusually strong late spring storms buffeting the region, this statement has been issued to alert those venturing into higher elevations in the NW mountains of the increased avalanche danger.
Weather Service ID WAZ513-518-519-019-042-501-502-ORZ011
Special Avalanche Statement
An increasingly dangerous snowpack is expected at higher elevations in the Cascades and Olympics late this week, especially on the volcanoes above 7 to 8000 ft
Following closely on the heels of several unusually potent and wet storms last week, a moderate to strong late spring storm Sunday produced 6 to 12 inches of additional new snow on terrain above 7 to 8000 feet, with yet another moderate front dropping 4 to 6 inches or more of new snow at higher elevations Tuesday night and Wednesday morning along with generally increasing winds. Overall, the strong June storms thus far have produced from around 2 to over 6 inches of water equivalent in many NW mountain locations, with heaviest amounts on the volcanoes. The associated increased accumulations of new snowfall at higher elevations on the NW volcanoes from Mt Hood northward through Mt Baker and in the Olympics have resulted in a generally increased avalanche danger in steeper terrain, with rain or wet snow producing increasing areas of wet, weak snow around the 6 to 7000 feet level and unusually large amounts of unstable new snow accumulations developing above 7 to 8000 feet. Wind deposits of 3 to 6 feet or more have been reported on southeast thru northeast exposures around the 9-10,000 ft level and above where intermittently strong winds were received. These new snow amounts taper off quickly below 6 to 7000 ft with only minor amounts of a trace to an inch or so of snow recorded at the 5000 ft level.
This weather has already resulted in increased avalanche activity at a variety of mid and upper elevations as evidenced by this wet slab near Chinook Pass around the 6 to 7000 ft elevation, and the large 3 to 6 ft slide on Mt Rainier around 12,800 ft that caught 11 climbers and skiers early last Saturday. The Mt Rainier avalanche appears to have initiated in an upper layer and stepped down to a deeper weak layer. Recent snowpack information from NPS rangers at higher elevations on Mt Rainier indicate that in addition to the sheer quantity of new snowfall amounts, a worrisome snowapck structure also exists. Field tests around the 11,000 ft level on Tuesday show significant energy stored within the upper part of the snowpack, as well as several weak layers buried within the late May and early June storm deposits. In most areas, the greatest accumulations of this potentially unstable snow structure exist on southeast through northeast exposures where greatest wind drifting has occured. Such widespread snow instability in June underscores the fact that the weather not the calendar dictates avalanche danger on higher elevations in any mountainous terrain.
The most recent storm system to affect the region has begun to move off to the east as of mid-day Wednesday. However, the associated upper level disturbance should maintain rather cool showery weather into late Thursday with another 6 to 10 inches of snow possible above the 7 to 8000 ft level over the next 36 hours and a few inches down to around 6000 ft. Following the departure of this upper level disturbance early Friday, a slow but very substantial warming and drying trend should move over the NW mid-late Friday through Sunday. With mostly fair skies and decreasing winds expected along with the highest freezing levels since last summer (10-12,000 ft late Friday rising to 13-15,000 ft mid-late Saturday and Sunday), the snowpack should become increasingly unstable and dangerous Friday through Sunday, with a wide variety of avalanche activity probable.
Although the NW snowpack has experienced considerable stabilization or melting over the past few weeks below about 5000 feet, the warming and sun should produce an increasing potential for wet loose or wet slabs around the 6-7000 ft level, along with an increasing likelihood of some large slab avalanches, icefall or cornice releases above 7 to 8000 ft. Also, melting snow from rocks or cliff areas are likely to trigger slides on the slopes below, with resulting loose or wet loose slides possibly triggering larger slab or wet slabs, depending on elevation and aspect. In short, this weekend should produce an increasing considerable danger around the 6 to 7000 ft level and a high to extreme avalanche danger on steeper higher elevation terrain above 7 to 8000 ft where signficant recent snowfall has been received.
As a result of these expected weather and avalanche conditions, travelers venturing into higher elevation terrain in the Cascades and Olympics are urged to be conservative in their decision making, very cautious in their route finding, and factor avalanche danger into their goals and route selection throughout the week ahead...as very few goals or routes are worth injury or worse. Please stay aware of expected weather and the snowpack over this time of transition toward a gradually more stable snowpack at higher elevations, and ratchet back both goals and expectations to help minimize potential avalanche involvement.
Please note that this statement does not apply to highways or operating ski areas...and applies mainly to higher elevation terrain in the Olympics...Washington Cascades...and Mt Hood...especially the volcanoes.
This statement will be updated as conditions warrant.
Vitaliy M wrote:rasgoat wrote:That route must be boot packed?
I have no idea, never been there. Know the weather was sh*t last couple of weeks for the most part so I have no idea how many people went up/made the trail etc.
IF SOMEONE ACTUALLY BEEN THERE RECENTLY PLEASE LET ME KNOW IF I SHOULD TAKE SNOW SHOES.
Vitaliy M wrote:Praying helped..my couple of friends and I broke a "dry" spell and summited today (1st people to summit from camp muir in 10 days according to the ranger).
Vitaliy M wrote:EastKing wrote:This weekend is NOT the weekend to climb Rainier due to the avy danger!! If you do, I will be praying extra hard for your success and good judgement. We already had an accident on that mountain last weekend. Hopefully it will be better by July!
Praying helped..my couple of friends and I broke a "dry" spell and summited today (1st people to summit from camp muir in 10 days according to the ranger). We explored the route Ingraham Direct (glacier route) on Saturday in the morning, and went up to 12K to check out snow conditions..Than talked to a guide who suggested it, if we can be fast...Since we are fast we left early and topped it bit past sunrise. We didn't see any avy danger on the route till we were finishing comming down, since snow was getting soft and unstable...we had a great time
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