Wednesday, December 10, 2008

Dust off the shovel & stack the wood!!!

So finally we can anticipate a big change in the weather starting Friday night. After one more mild night we will start to cool Thurs night a few degrees and then by Saturday high temps will be 20-30 degrees colder. We can definitely be sure of that and excited about round the clock snow making, till at least Wed. Lows in the teens and single digits with highs in the teens and 20’s. No more inversions with the colder temps the higher you go up.

The cold front along with its cold unstable air will generated snow showers Saturday that will only add up to a few inches of fluffy powder.

The uncertainty is the amount of snow we will get Sun-Wed with a storm that will follow the cold front. The jet stream is very amplified which means way up and way down. The jet goes into Canada, back out into the Pacific near Washington, and then back into Central California someplace over the weekend. The storm will slowly make its way off the coast near Washington on Sunday and then back thru CA by Tues. This will direct moisture over us with continuous off and on snow showers Sun-Tues. The amount depends on how far out over the water the storm goes, how fast it moves down the coast, and where exactly the jet comes back in over CA. Models disagree a little with some showing a slightly faster storm and not over the ocean as much, which is drier, and some that have a slower storm that goes out well over the ocean, which would be wetter. There will not be a significant moisture tap so snow will be light to moderate but the duration and high snow ratios could mean significant amounts.

Let’s talk some number possibilities from low to high. This will be a very cold period of snow so snow ratios will be around 15:1 at lake level, and 20:1-30:1 on the mountain. Models have shown between .5 inches of liquid up to 2.5 inches collectively over the 3 day period. He is a chart of what those numbers would be at .5, 1, 1.5, 2, & 2.5 inches from left to right.

15-1 7." 15" 22" 30" 37"
20-1 10" 20" 30" 40" 50"
30-1 15" 30" 45" 60" 75"

So as you can see with the cold temps and low moisture content of the snow it will pile up pretty fast over the period. Looks like worst case scenario on the Mtn. is 10” at the base and 15” on top. Best case scenario is over 4ft. at the base & 6+ ft. on top. I am going to go with around the 1” numbers of 20-30 inches by Wed. We’ll see if this storm can get to its full potential, it’s still early. I will update you with how much liquid models are predicting each day as we get closer.

In the extended the jet looks to flatten out a little. A small storm may affect us Thursday and then a bigger storm for the weekend that would have significant moisture to work with. We will have to wait a few more days to get a better guess on the track of that storm. It should stay cold and unsettled in general though as we go into Christmas week. Storm update on Friday as I’ll be in the air tomorrow. BA

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