Where's All The New Snow??

The 3:30 pm forecast for the West slopes of the Cascades has a winter storm watch from Friday evening through Saturday afternoon, so maybe our luck is changing.

6" at Baker and 4" at Paradise! That's looking a little better .

When the upper level airflow is from the northwest over the Pacific NW, that means we are on the east side of an upper level ridge. The air to the east of an upper level ridge is generally sinking. Sinking air compresses, heats, and evaporates any precipitation and most clouds. Except for a minor, orographic component to the airflow caused by the mountains and producing some mountain clouds and snow flurries, you will generally find clear air to the east of a ridge. Since it is clear, nighttime cooling will cause fog and low clouds in the lowlands and valleys. Sometimes this valley fog blows through the passes causing snow flurries near the passes, but no real accumulations.

When the upper level airflow is from the southwest over the Pacific NW, that means we are on the east side of an upper level trough (or the west side of an upper level ridge). The air to the east of an upper level trough is generally rising. Rising air expands cools and results in condensation (i.e., clouds and precipitation).

If you want to know what type of weather to expect, look at the upper level wave pattern; that is, the position of the ridges and troughs. Try this link

weather.unisys.com/nam/4panel/nam_500_4panel.html


Bryan Scott

That's what I'm talking about. Nice explanation Bryan. Thanks!!

This was posted 12/13/07:


Consistent Snow Pattern Developing

Fasten your seat belts. Good news for powder hounds.

I finally see a weather pattern developing on the computer models to have the potential to completely open most of our Cascade resorts. This pattern indicates a consistent snowy and cool airflow.

It will be a snow machine in the Cascades. What I see is a series moderate storms, with some windy periods, moderate snowfall with each storm and partial clearing between storms. Snow Levels will be 1000-3000ft, so everyone will get high quality powder with improved coverage and surface conditions. The cycle time of each storm will be 12-24 hours with breaks of 12hrs. I expect 2-4 feet of snow in the next 7 days, possibly more. Be careful on the roadway driving up, take it slow. Stay inbounds on the slopes.

Finish those holiday obligations, because you are gonna want to have time to hit it.

Here is how it looks. Snow levels for the next seven days and beyond: 1000- 3000ft. Ya gotta love it. Friday night into Saturday: 4-9 inches by Saturday afternoon. A break Saturday night, some new snow 1-3”. A break Sunday morning. Snow increasing late Sunday night into Monday: New dumpage by later Monday: 6-15”. That should be a good powder day. Another system will come in for Wednesday into Thursday and that will be worth another 5-12”. Primo powder riding. More to come after that. In fact the following weekend looks fanstatic. Long live " LA NINA"

Might be a break for a day or two around Christmas, but get ready --- La Nina will produce more deep snowfall in the months to come, making up for the slow start. Even with the slow start the next 7-12 days will really get us up to speed and La Nina holds the promise of many deep powder days beyond the horizon into the New Year.

Happy Holidays
Grand Pubah of Powder

Meteorologist

Larry Schick


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