Friday, December 24, 2010

Twas the Night Before.......

Sitting here between the tree and the fire with my feet up and doing what I find relaxing which is looking at weather models. I just ran quite a few as this is the first chance I have had to sit down since leaving for the in-laws yesterday with the car packed with kids, presents, pets, and just enough room for my suitcase. Spent this morning doing last minute shopping and wrapping presents and now I am taking advantage of everyone napping. Before I left town yesterday I found out what happens when you combine over 200 inches of snow in the month leading up to Christmas with sunny skies and good driving conditions 2 days before. I didn't get any skiing in yesterday but I did get to experience waiting in line with everyone driving to and from work. It must be some of the best skiing conditions in the resorts history for this time of year. I hope everyone enjoys the great snow over the holidays.

The strength of the jetstream this fall may be attributed to the warmer than average waters in the far Western Pacific where the jetstream originates. That is about the only place you will find warm water in the Pacific as the Eastern and Equatorial areas are well below average. Now that we are going into winter the jetstream will be at it's strongest and we just need to help direct it into CA.

The ridge over the Rockies extends all the way up to Canada and the storm moving in for Christmas day will run right into the back of it. I have no changes today in my ideas of what will happen with the storm as it tilts to a South-North orientation and limits the amount of moisture that can push over the crest into the Tahoe Basin. Precip may begin briefly as rain on Saturday at lake level before changing to snow. Snowfall amounts will be light with 2-4 inches in the Village and 4-8 inches on top by Sunday morning.

We clear out on Sunday with a break Monday and Tuesday. The pattern in the Pacific is going to change next week with ridging out around 140w & 30n, and then it builds Northward towards 50n. This will allow a cold storm with decent moisture to move in on Wednesday with snow amounts looking to be in the 1+ foot range. What will help with totals is that the storm will bring in lots of cold air which will increase snow ratios to 20:1 or better by Wednesday night. What will keep the storm from being big is that it will be fairly fast moving. Behind the storm temps don't get out of the 20's into New Year's weekend.

With the ridge expanding Northward out in the Pacific towards the end of next week the storms will all be pushed to our North. In the pattern that will setup with the ridge off the coast, we will see more cold than snow with our snow chances coming as inside sliders. These are cold storms with light amounts of snow. We may see an inside slider on New Year's Day that brings us light amounts of snow for the weekend.

This pattern may last for 10 days or more which means we may get shots of cold and light snow, but no big storms for a while. We will look for retrogression of the ridge far enough West to allow storms to dive down over water and into CA, or for the ridge to move far enough North that the Pacific Jetstream can come underneath into CA. One of those should happen in January but we will have to wait and see. At least the ridge won't be right over CA bringing warm air. There is a lot of cold air pouring into the country in January, so my hope is that the cold will back far enough West that it taps the Pacific moisture and maybe merges with the jetstream similar to what we saw in November.

Everyone is waking up so it's back to Holiday fun with the family. I hope to post a Christmas Day post and maybe there will be a present in the weather models. BA

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