Wednesday, March 27, 2013

1-2 Feet Sun-Mon?

The unsettled pattern continues into Friday with snow levels 6500-7500 ft. We have a better chance of seeing light snow on the mountain tonight through Friday morning, but only expecting a light coating.

On Friday the snow levels will begin to rise to and maybe above 8000 ft. as warmer air is drawn up ahead of the approaching storm for the weekend. The good news is that the showers should stop later Friday into Saturday morning ahead of the storm.

This cut-off low slowly approaching from the West will be tapping into some subtropical moisture. The low has cold air at the center but the snow levels will start off near 8000 ft. later Saturday into Saturday night as the heavier precip moves in. Then on Sunday as the center of the low moves onshore snow levels should begin to drop near 7000 ft. Sunday night into Monday as the center of the low moves over Central CA the snow levels should drop to the base.

When we have a 2 day storm with heavy precip and falling snow levels it makes the snowfall forecast very tricky. The easiest forecast is above 8000 ft. where all snow will fall. Below that is the tricky part. The GFS forecast model is still the most bullish with total liquid over the Basin. With the slow moving nature of the low bringing precip bringing 48+ hours of precip and the subtropical tap, I am leaning towards the bigger totals.

For now I am going to break the storm into 12 hour increments: Sat night, Sunday, Sun night, and Monday. I'm going to put the snow levels at 8000 ft. Sat night, 7000 ft. Sunday, and 6000-6500 ft. Sun night into Monday. That would give us 1-2 feet on the mountain by Monday night and several inches at the base.

It looks like we will only have a 2-3 day break before the next storm begins to move in by next Thursday. This system is bigger and has more moisture being pulled in. The forecast models agree on snow levels rising and starting out in the 7000-8000 ft. range as moisture streams into the Sierra ahead of a large low pressure system approaching the West Coast. Then the weekend of the 6th the low moves inland over the the Pacific NW bringing heavy precip to the Sierra. This could be a mult-day precip event.

The forecast models bring in colder air into the weekend of the 6th bringing all snow to the mountain. We will have to watch this storm over the next week because if the European forecast model runs verify we could see several feet of snow on the mountain the 4th-8th. This could be the stormiest period since December.

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