Saturday, November 12, 2011

Powder for Opening Weekend....

Not to many changes in the forecast for the next couple of weeks as we just have to wait about 6 more days until the snow flies. After the cold front pushes through tonight bringing maybe a snow shower we will have a flat ridge keeping all the activity to our North until Friday. The snow continues to fly out of the snow guns however as we have had plenty of cold air at night. We should be on track for opening day and day 2 should be a powder day.

I have been alluding to the pattern change that will begin on Friday for a while now. Everything is lining up for us as far as the global teleconnections and the setup in the Pacific. The MJO Madden Julian Oscillation is in phase 7 as it moves through the Western Pacific. It will be going into phase 8 then 1 this week. Phase 1 in November usually means a cold trough along the West coast. Add in the -PNA Pacific North American teleconnection and we have what we need to have the ridge out to the North of Hawaii opening the door to cold storms to drop down the West Coast.

There will be a strong cold trough digging down the West coast towards the end of the week and it should begin to pushing into our region by Friday night. As the main low slowly works its way down the coast we will have to see how much moisture it can draw in from off of the Pacific. The air associated with the trough is cold and the ocean temps are still fairly warm, so we should see an ok moisture tap.

Right now it's too early to talk snowfall amounts, but currently the models don't show a ton of moisture. With the cold air though and forecasts for and inch of liquid plus over the weekend we could be measuring it in feet not inches. In these situations with the low slowly working down the coast and really cold air pouring in, we tend to get continuous snow showers from the orographics of the cold NW flow behind the cold front, and sometimes the snow can start to pile up.

We will have to continue to keep an eye on the first storm for next weekend. That is not the end as that should just be the start of the 7-10 period of a series of cold storms diving into the West Coast. The first storm next weekend could be the weakest and just be the one opening the door. There is another storm diving into the Pacific NW Tuesday and again around Thanksgiving or the day after. Looking at the long-range models it looks as if the storms get progressivel stronger as the pattern sets in.

This pattern of the -PNA and the trough along the West Coast should be the signature of this upcoming Winter. If this pattern continues to develop here for the second half of November though we may have another great start to the season. BA

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