Monday, February 2, 2009

The Details....Mon. P.M.

These cut-off storms are enough to drive you crazy. I don't want to pinpoint any details because they could change with the slightest change in track of the storms. I will say that we can bet on at least 6 inches for everyone and then go up from there with better chance of up to a foot above 7000 ft.

First storm will head towards CA and then split on Thursday with one piece coming across NorCal and Tahoe, and the other piece into SoCal. This will cut off the strong moisture tap from the northern piece, but it will also keep snow levels lower without the warm subtropical moisture. Snow levels should start above 7000 ft. but then quickly lower to lake level during the day Thursday. Several inches of snow will fall with more the closer you are to the Western Sierra Crest.

A cold front with another cut-off low behind it will move in on Friday. The cold front itself will enhance snowfall and create several more inches for everyone with snow levels below 5000 ft. Cut-off then comes down the coast and keeps the snow showers going into possibly Sat. morning. Models have this low staying offshore then coming in across SoCal so the heaviest precip would be to our South and snow showers would be heavier the closer you are to the crest. A slight jog East in the track and we will get more snow.

Hopefully amounts will become more clear and go up in the next two days. Good news is that the storm will be mostly snow for all.

Models have no clue in the extended. Several storms are lined up to come into the West Coast every few days. Latest models want to keep the heaviest snow just to our North with the pesky high pressure ridge sitting out at 140w. Still thinking there will be a southward shift in the jet the next couple of weeks with the block in Canada moving towards Alaska. Therefore I will ignore the models beyond 5 days and just say that the weather pattern will stay unsettled. BA


Anonymous said...

What is a "cut-off low"? You use it regularly, but I can't find a good definition.

BA said...

A cut off low is when an area of low pressure is pinched off from from the main flow of the jetstream, usually caused by a high pressure. It then has no winds to steer it and it just kind of wanders in the ocean waiting for another storm to push it along. That is why it is so hard to forecast their path.

Sundance62 said...

I much appreciate this blog, and will become a regular reader. Thanks!

Anonymous said...

Hey i just wanted to thank you for posting on the blog so regularly. I'm always interested in the weather for Tahoe. It's been really nice having you break down the forecasts and explain them in depth. You seem to be very accurate with your predictions and don't throw around bogus forecasts. Thanks again. Cant wait to hear news on the coming weather pattern.

Tom said...

Any help with what might happen in Park City Friday - Thursday?