Tuesday, December 21, 2010

First Day or Middle of Winter?

Northstar has picked up 6 feet with this storm, 8 feet in the last 7 days, and 245 inches this season already. That is 70% of their annual average and that is all before the first day of Winter today!

The storm for tonight and Wednesday is approaching the coast and already splitting into 2 pieces as it hits the backside of the ridge to our East. You can see this very clearly on Satellite. This will send the heaviest precip to our North and South. It was thought earlier that the ridge would be a little further East and the storm would not split. This will decrease our snowfall amounts tonight and Wednesday. I mentioned last week the potential that the trough could dig too deep off the coast and drive the jetstream to our South, which is happening. The heaviest snow should fall in the early morning hours with 3-6 inches expected in the Village and 6-9 inches on top. This will be a nice blanket of powder on top of the incredible base we received this weekend.

Then we clear out for Thursday through Christmas day with temps in the 30's Thursday and then the 40's Friday & Saturday. The next storm approaches for Saturday night. This will be a cold and fast moving storm that will drop around 6-12 inches in the Village and 12-18 inches on top Saturday night. We should clear out again on Sunday.

Beyond Sunday the models have no agreement whatsoever as they try to figure out where the ridge will set-up on the Pacific. The GFS wants to bring the jetstream into Northern CA with significan snow on Monday but the rest of the models bring in the ridge and push all precip into the Pacific NW. Will have to keep an eye on it because the GFS has been consistent for the last few model runs. By the middle of the week all the models agree that the jetstream returns bringing more storms into the end of next week. The trend has been to set up the ridge further West to the North of Hawaii which puts us on the East side (warm side) of the trough. That could mean some milder storms with low elevation rain.

Looking super long-range into the first week of January the ridge may push further East in the Pacific putting us back on the cold side of the trough and bringing colder storms. Looking at the teleconnections the block over Greenland is still forecast to weaken which would assist in keeping the storm flow progressive and prevent any long-term ridging. The jetstream will be really strong by January so it would be hard for a ridge to set up for very long. I still don't see the classic La Nina setting up yet with the large blocking high in the Gulf of Alaska. We should see that start to happen in January and we should see a cold trough set up near the West Coast with the jetstream coming underneath the blocking high into the West Coast. Wouldn't mind a little help from the MJO but it looks like it is running laps between the Maritime Continent and West Pacific. It is so weak that it wouldn't have any affect on our Weather for now. If we could get another 100 inch storm cycle again in January we could start closing in on the yearly average. Should be a fun winter, which amazingly only just starts today. BA

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