Thursday, December 30, 2010

A Great Day......

I can't remember a day in December with this much snow on the ground and such great conditions. Northstar picked up another 2 inches yesterday bringing the storm total to 23 inches and the season total to 281 inches (over 23 feet). That means Northstar has now picked up 80% of their annual snowfall average and we are only 1 week into winter.

The cut-off low coming down the coast this weekend will be very unpredictable in it's path and the slightest shift East or West makes a big difference in snowfall. Right now the models have the track a little further West than yesterday which means a little less snow makes it into Tahoe. The best chance for snow looks to be Saturday night. The snow would come in periods of light snow showers through the weekend. The range of totals for the weekend are between 2-10 inches. We will have to continue to watch the track because we could get nothing and we could get a little more.

There is a another cut-off that looks to come down off the coast on Tuesday. This one looks even drier than the one for this weekend. After that the ridge moves a little closer to the coast and all storms are pushed into the Pacific NW until the end of next week.

The position of the ridge is between 30n and 40n in the Pacific over the next week, which is basically straight off the coast of CA. At that position the longitude of the ridge every 10 degrees East or West has a big difference in our weather during the winter. At 140w where the ridge is forecast over the next week, it is too close to us & the storms are directed to our North and then down to our East so we only see inside sliders. As the ridge retrogrades Westward towards 150w the storms then drop down just off the coast and into CA. These are normally cold and small-moderate sized storms. As the ridge retrogrades even further West towards 160w the storms comedown even further off the coast and can pick up more moisture before hitting CA. There is a lot more to it but that helps to explain the main driver of what I'm looking for in the long-range forecast.

What we need is for the position of the ridge to retrograde Westward by the end of next week in order to open the storm door back up. Models are suggesting that the ridge moves back towards 150w by the 8th which would allow a small cold storm for that weekend. Then retrogression towards 160w which would allow subsequent stronger storms the second week of the month. Looking at the teleconnections I don't see anything right now that points towards another blockbuster storm. Just a series of cold storms that can still do the job with quick dumps like we saw yesterday. Sometimes my gut is more accurate than the weather models and I think that by the middle of the month or the 3rd week of January we will see something break and the ingredients come together for a big storm. Or maybe that's just my breakfast. It's been a fun ride so far......BA

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