Winter storm near: 4 to 6 feet?
UPDATE 4:42 PM….Everything still on track. Light snow started falling this morning at Squaw Valley and other parts of the Tahoe Basin. Elsewhere it was mixed with rain but snow levels have been falling and we should be seeing widespread snow throughout the basin by this evening. Snow totals by Saturday morning should be about a foot at 7000 feet with a few inches around the lake. After a brief lull midday Saturday, temperatures will fall further as another surge of energy passes over the Sierra Saturday night and Sunday. This will be a bigger storm, with more intense snowfall, perhaps reaching 3 to 4 inches per hour in favored locations. Snow to water ratios will be 20 to 1 over most of the basin and higher at the higher elevations. After one more burst on Sunday night we should awake Monday morning to a foot or more of snow around the Lake, three feet at the mountain passes and a chance for 3 to 5 feet at the highest peaks around the Tahoe region. Thanksgiving holiday still looking clear as a ridge of high pressure moves in early next week behind these storms.
FRIDAY NOVEMBER 19…4:52 am…
A very cold low pressure system forming in the Gulf of Alaska is moving south toward California this morning and will bring an eye-popping, season-opening winter storm to Tahoe this weekend.
This system is now forecast to tap into a little more moisture than previously forecast, and the forecasted snow totals are going up accordingly. With the cold temperatures, especially on Saturday and Sunday, the snow-to-water ratios will be high, around 20-to-1. That means each inch of water precipitation will be converted into 20 inches of snow. And the latest forecasts are calling for about 3 inches of precipitation.
Not all of that will be falling during the coldest period. But the Sacramento office of the National Weather Service says that four feet of snow is likely at the highest elevations by Monday. The Reno office is going further, suggesting that some parts of the Tahoe region could see six feet of snow by the time this storm moves east on Monday.
The snow will come in three distinct waves. The first will be this afternoon and tonight. Tahoe’s peaks could see a foot or more from this wave by early Saturday. The second wave will be Saturday night into Sunday morning. We could see blizzard conditions with this wave and very heavy snowfall, 3 inches per hour or more. A third, more moderate wave is due Sunday afternoon before the snowfall turns to snow showers.
The showers are likely to continue through Monday. A separate low pressure system is forecast to move south down the east side of the Cascades and the Sierra on Tuesday. But it has been trending farther east and will not likely bring much snow to Tahoe, if any.
But it will bring a blast of cold, arctic air, and that cold air should remain present through Thanksgiving Day, although each day will be a little warmer. But plan on a cold, clear and very white Thanksgiving 2010.
Stay tuned here and we will update you as this storm takes shape.
At 7000 feet
Regional radar with rain/snow mix: