Friday, December 10, 2010

Cold and Snow......

You can start to get a little excited now about the long range forecast for snow. I believe the models are starting to catch onto the fact that the MJO will be in the Western Pacific in about a week and will stay there for about a week. That will bring the jetstream associated with a cold Pacific low combined with a deep moisture tap to Northern CA by the end of next week.

In the meantime we have a ridge building in that will clear things up and bring us mild temps through the weekend and into Monday. By Tuesday the blocking high pressure over the Aleutian Islands that has been keeping us on the warm side of the jetstream is going to breakdown. The low pressure in the Northeast Pacific is going to shift East and bring the storm track into Northern CA by Tuesday.

We look to get a small storm Tuesday into Wednesday with snow levels dropping below lake level. Right now it looks like several inches with this storm maybe a bit more up high, but we won't be measuring in feet.

That may change however by next weekend as the jetstream moves over us and pulls in moisture from across the Pacific. We should begin to see a series of storms by next weekend and into the following week. It is not clear how cold they will be, but there will be plenty of cold to the North trying to work it's way in.

As the NAO trends positive towards the end of the month the block in the North Atlantic will weaken. This should allow the cold over the East to move West by the end of the month. I am expecting a cold trough to form along the West Coast as we go into January along with a mature La Nina jetstream. The MJO may help us get through December with decent snow before we won't need much help in January. Stay tuned as this pattern change develops over the next week. BA

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