Sunday, December 20, 2009


The title is how my brain feels trying to figure out the weather pattern for the next couple of weeks.

It's been a few days since the last post for a few reasons. First of all, the models in the short term have been consistent the past few days until this morning with the storm for Mon/Tues. Secondly, the long range models have been all over the place and I have been going crazy trying to get a handle on what is going to happen over the next few weeks. You may notice that other forecasters are keeping quiet or are struggling in the long-range. Thirdly, I have been spending a lot of time the past few days on making forecasts for and tracking the historic blizzard that just hit the East Coast. Lots of friends and family back there that still depend on me for their weather as well. Philly had it's 2nd biggest snowfall in history with 2 feet and places in NJ blew away their seasonal averages for snowfall in one storm.

Ok, so back to our weather. There is a big storm off the Pacific NW coast that is going to send two waves of moisture in our direction. One tonight and the other tomorrow night. First wave is looking pretty weak and should only trigger snow showers with little accumulation. The second wave tomorrow afternoon and night should be stronger with more snowfall. Up until this morning models were pretty consistent in showing 3-6 inches at the lake with 6-9 inches above 7000. This mornings 6z & 12z GFS & NAM models have backed way off on the second wave. EC models still showing decent precip. Models not doing so well a few days out on snow totals. They blew it last weekend showing a foot of snow for last Tuesday and we got an inch. Best bet may be to cut the snow totals in half for Monday night's storm for now to be safe. That would be 1-3 inches at lake level with 3-5 above 7000. We wil have watch the storm track and should have a good idea on totals by tomorrow morning.

One thing that the storm will do is bring in colder air. Temps only in the 20's on the mountains for Tuesday and the 30's the rest of the week into the weekend.

Looking long range the models are all over the place. What is going to happen is the the ridge is going to build in to our North over the Pacific NW and British Columbia next weekend. There is also going to be a big low pressure spinning in the Gulf of Alaska sending energy towards the West Coast. The question is what happens with the energy? We have lost the chance at tropical forcing from the MJO that has now started to cycle back around into phase 1 and won't help us until at least a few weeks from now. Some models suggesting that moisture can come under the ridge and bring us snow next weekend. Others showing the ridge too far South and the moisture either falling apart or going into Southern CA.

If the moisture can't come under the ridge it appears as if the next chance for snow will be the middle of the following week. Forecasts are for the block in the North Atlantic to ease and allow the ridge over the Pacific NW to head East. This may allow the energy from the next low that moves into the Gulf of Alaska to come in from the North into CA.

What we are waiting for is for the affects from El Nino to kick in which usually starts to happen by January. Ridges should continue to try and Build in over British Columbia as we go into the winter and force the abundance of cold air in Canada down into the West. As the Southern jet finally gets active it should start sending moisture towards CA under the ridge similar to what happened last week. This may just be a confusing period the next couple of weeks for the models as the seasonal pattern changes take shape going into the winter. Stay tuned as I hope to get a better handle on what happens with the pattern next weekend over the next few days.......BA

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