This Weekend's Weather and Avalanche Guess

This weekend's avalanche and weather guess:

Alrighty, we're getting a ton of phone calls about what we think the weather is going to do this weekend.  Here's my best guess:

First:  Use this forecast model from the University of Washington.  It shows the pressure systems at the 500mb heights (approx 17,000 feet).  You can see the upper level low pressure circulating and creeping towards Washington State.  The upper level low pressure has been creating unstable air and has been the source of much of our precipitation and clouds over the last couple of weeks.  As the low ciculates, grabs moisture from the ocean, it's already cool, and it brings it right to the cascades.  As the moisture goes over the mountains, it is cooled as it is forced up, which it will readily do because of the already present unstable low pressure system.  That causes the clouds and precipitation.

The next model can be accessed here: University of Washington 4/3km Profile.  This model is a x-section of the atmosphere from 0 - approximately 17,000 feet.  The red lines are humidities.  Here you can see the effect of surface warming each day and the low level instability that creates. 

The two models give a good clue that there is some crazy unstable air at the surface and up high that we are going to have to deal with beginning this evening through as far as we can see into Saturday.  This is a contrast to the summer upper level high pressure ridges that dominate the PNW weather.  There is often each day in the summer, surface low pressure over eastern washinton that sucks in cool marine air from the ocean.  That gives us lower level clouds and fair skies above.

This system is different.  There is upper AND lower level low pressure giving high high lapse rates that make clouds and precipitation probable along Mt. Rainier's entire elevational profile.

So do proceed with caution.  If you're bent on coming out for a try, please bring some navigational aids like a GPS and a compass and map and know how to use them.  Bring extra warm clothes and the sturdier tent.  Get a good weather briefing from the CIC before you head up.

With snowfall and precipitation and wind comes avalanche danger.  No one issues an avalanche forecast for Mt. Rainier in June.  However, there are plenty of anecdotal observations coming in from rangers, climbers, and guides.  Yes, there is some observed instability over the last two days.  Easy to moderate failures have been observed both yesterday and the day before at and above 11,000.  However, climbers did summit yesterday and today on the disappointment cleaver.

I anticipate that through the next 48 hours, climbing above high camps will be limited.  It's still too soon to tell about Saturday night and Sunday.

- Stefan

Come Prepared and in the Know...

The weather over the past week here at Mt. Rainier has been more indicative of what we would see in early spring than mid June.  We recently received a substantial amount of new snow at elevations above 8000'.  What this means is the snow pack on the upper mountain is different than what folks normally see in June.  Large drifted pockets of unconsolidated snow create hazardous and tiring conditions for traveling.  We highly encourage climbers to have knowledge of avalanche assessment, as well as dialed partner rescue skills using a transceiver, probe and shovel.

Heavily traveled routes such as the DC and the Emmons are no different than any other routes on the mountain in regards to weather and avalanche hazard.  Just because other climbing parties are ascending with you does not make the route safe.  Use your sense of general mountain awareness and don't climb blindly into hazardous terrain.  If you have a feeling that avalanche danger is higher than what you're comfortable with, or that weather might be moving in sooner than you had thought, we encourage you to descend.  Mt. Rainier will be here for quite a while, and it's not worth risking your life if conditions aren't optimal.

Lastly, when you do climb, think about throwing in a large puffy, rescue tarp, shovel (in addition to a tranceiver and a probe), stove and extra food into your pack.  If the weather turns south and you end up having to spend the night out on the upper mountain, you're chances of survival are largely increased.  Consider laying a track of your ascent on your GPS, so if the weather moves in and visibility decreases, you'll have a detailed descent route to find your way back to camp.

Even though we're moving out of this most recent storm cycle, keep in mind that with the upcoming warm days, avalanche danger will spike prior to snow pack consolidation, and there most likely won't be splitter high pressure like we're used to seeing.

Come prepared so you can come back again!