Sunday, December 26, 2010

One Last Present

Northstar picked up 11 inches on top in the past 24 hours and 7 of that came overnight. We should see clouds today and tomorrow as the moist flow off the Pacific stays just to our North.

We could see snow ahead of the next storm start as early as Tuesday as warm air overrides the cold air in place creating scattered snow showers. This will be a 2 part storm with the jetstream taking aim Tuesday night and then a cold front pushing through on Wednesday. The jetstream actually has quite a bit of moisture but the cold front will push it South fairly quickly and usher in really cold air. Right now I am expecting 1-2 feet on the mountain. 6-12 inches will come on Tuesday night and then double down on that Wednesday with the cold front. The tricky thing with storms like this with so much cold air is the post frontal snow showers and high snow:water ratios. By Wednesday night the temps will be in the single digits which means 30:1 ratios. Air that cold is unstable because it cannot hold much moisture. That meas we could see numerous snow showers into Wednesday night that could pile up really fast due to the fluff. That could increase the snowfall totals. We will need to fine tune the totals the next 2 days but it looks like a nice moderate sized dump for Tahoe to freshen things up for the New Year's weekend.

The temps will struggle to get out of the teens Thursday and Friday, and then will stay in the 20's into the weekend. Another small storm is looking to move in over New Year's weekend with some light snow possible. This storm is looking like it could split with the heaviest precip to our South. It will reinforce the cold.

Looking long-term there is a difference in opinion on what the ridge will do out in the Pacific as it sits around 140-150w. The GFS is consistent in it's idea of the ridge expanding North and keeping the storms to our North and Tahoe dry for about 10 days. The Euro last night and the latest GFS run this morning are suggesting a slightly flatter ridge which would allow small cold storms to continue the first week of January. I would expect retrogression of the ridge a little further West by the second week of the month allowing the storms a little more over water trajectory and bigger storms for us. The pattern continues to suggest cold and unsettled into January with no warm moist subtropical taps for a while. That could change, but this is what I was expecting for January. Cold storms from the North can be fairly big if they have a good over water path and they have higher snow:water ratios. Stay tuned.........BA

No comments: