Update 5 PM:

Snow has been falling all day.  I was at Alpine Meadows and about 6 inches accumulated at the base and 8-9 up top during the day.  That is at or just over the high end of the forecast for today.  Expecting another foot tonight.  Snowing all the way to Reno with snow levels down between 4000-5000 feet.  

The forecast is on track and snow will continue all night.  We will tally it up on the morning for 24 hour snowfall.  The NWS Reno just issues a Blizzard Warning.  They only do that on average once every other year.  So this is a strong storm coming Wednesday night.  Here is a quote from their blizzard warning.

"This is a life-threatening situation. Do not attempt to travel Wednesday evening through Thursday morning! Road crews and first responders may not be able to rescue you."

Here is the live forecast video I shot at 4 PM from the base of Alpine Meadows.  

Original Post from 7 AM:

We saw some light snow showers move in Monday afternoon and overnight.  The ski resorts on the east side of the lake are reporting 0-1 inches this morning over the past 24 hours.  On the west side of the lake reports of 1-2 inches, with up to 3 inches southwest of the lake down at Bear Valley and Dodge Ridge.

Not much change to the forecast this morning.  The next wave is pushing in this morning and then the strong storm is still on tap for Wednesday night into Thursday before the storms end by Friday morning.  I promised I would shave off the beard if we have a ski resort report 36 inches in 24 hours this season.  Thursday morning there's an outside chance that a mountain comes close to that.

Tuesday:

As the next wave pushes in Tuesday into Tuesday night, we will see an increase in moisture and precipitation over the area.  We should see light snow this morning becoming steadier this afternoon, and then some heavier snow Tuesday night.  Winds stay pretty light for Tuesday.

There is still some uncertainty among the forecast models this morning with this system, with where the heaviest precip will fall.  They still have a range of 0.7 - 1.8 inches of total precip near the crest.  The GFS forecast model has the heavier precip amounts now NW of the lake with up to 1.8 inches, and the European model has the lower end of 1 inch near the crest.  The total model average is 1.2 inches.

Here is a look at the total precipitation forecast on the WPC model by Wednesday morning.

The Euro/GFS average used for the snowfall forecast is 1.4 inches, 2 tenths above the average.  Here is the final snowfall forecast for this system by Wednesday morning.  It is about the same as yesterday.

We will have to keep a close eye on the radar today to see how much moisture does push in over the area.  I'll do an evening update if necessary, and I'm always tweeting updates on the Tahoe Weather Twitter page.  Here is a look at the possible average snow ratios, snow levels, and ridge gusts for this system.

Wednesday:

Wednesday morning we may see much lighter snow as the Tuesday system departs and the Wednesday night storm approaches.  The GFS model still keeps us pretty dry through the day with only up to an inch of additional snowfall as it holds off on the next storm until Wednesday evening.  The European model is still pushing the next storm in a little earlier with heavy snowfall pushing in during the afternoon.  

The storm moving in by Wednesday evening is much stronger than the Tuesday system.  It is going to tap into plenty of moisture off the Pacific and point that atmospheric river right at Central CA by Wednesday night.

We will also see the strong jet stream push in over the area with plenty of forcing, and strong winds increasing through the day on Wednesday.  Ridgetop gusts should be to 70+ mph by afternoon, likely shutting down some of the upper mountain lifts.  Then increasing to 100+ mph Wednesday night.

We will see some warmer air work in ahead of the cold front Wednesday into Wednesday night.  Snow levels look like they will increase to 6,500 feet by Wednesday evening meaning a change to rain at lake level and at the base of the mountains with low bases.  The models show them peaking out around 7,000 feet by midnight Wednesday night before falling to 6,000 feet Thursday morning as the cold front moves through.  The heavy precipitation rates could push the snow levels slightly lower.

By Thursday morning we could see an additional 14-25 inches of snow the mountains above 7,000 feet.  At lake level, we could see some light accumulations Wednesday morning before a change to rain, and maybe light accumulations by Thursday morning depending on how fast the snow levels come back down.  

Thursday:

Heavy snow continues Thursday as the front moves through and heavy snow showers fire up behind the front with plenty of moisture still flowing in.  Winds will still be strong with gusts to 95+ mph hour on the mountain tops in the morning, then coming down some during the afternoon.  Snow levels continue to fall, dropping near 4,000 feet by evening.  Expect most upper mountain lifts to be closed at least in the morning, and delayed lift openings to dig out and for avalanche control operations.

The snow should turn more showery with more scattered bands going into Thursday night.  Colder air continues to move in with snow levels dropping below 4,000 feet.  So the last several inches of snow should be nice and powdery.  The winds should continue to come down through Thursday night.  The snow should end by Friday morning.

There is less agreement this morning among the forecast models for total precipitation amounts with this storm.  Total precipitation forecasts have a high end along the crest of 3 - 5.3  inches, with lesser amounts east across the basin.  But plenty of spillover to the east side of the lake.  The low end of the range went down a little, and the high end went up almost an inch from yesterday. 

The GFS is on the low end now with 3 inches and the European on the high end with 5.3 inches.  Both have support from other models.  The average of the two used in the snowfall forecast is 4.2 inches which is close to the total model average.  Here is the NAM model through Friday morning which falls in the middle.

Here is the updated forecast for additional snowfall with this storm by Friday morning.  It is about the same as yesterday.

Here is the possible average snow ratios, snow levels, and ridge gusts for this storm.

Storm Totals:

The European and GFS models are averaging 5.5 inches of total precip near the crest and up to 4 inches for the east side of the lake by Friday morning.  The total model average is around 5.1 inches near the crest.  That is up slightly from yesterday even though the range expanded.  I'd like to see a lot more agreement tomorrow, but this is strong storm with a strong jet and AR, so we will likely see closer to the higher end.

Total snowfall by Friday on the mountains, based on the latest model runs, could still be in the 2.5 - 5.5 feet range from east to west across the lake.  At lake level 1-2+ feet possible.

High pressure builds in over the West Coast Friday into Saturday bringing a return of nice weather.  Friday should be a nice powder day.

The next trough approaches the coast Sunday, but it will encounter the ridge over the area and weaken as it pushes in.  The latest model runs still show a few inches of snow possible Sunday night so we will keep an eye on it.

Then high pressure builds in along the West Coast with a dry pattern expected through the last week of January. 

As I mentioned yesterday, there are a few signs on the long-range ensemble runs that the ridge could shift towards the Gulf of Alaska going towards the beginning of February.  That could possibly allow storms to push under the ridge into CA.  That is showing up on the GFS ensemble control runs this morning.

Maybe the dry spell only lasts until the end of the month?  We have plenty to deal with this week and then we can start to look at the long-range more when we start the dry period.

Stay tuned...BA

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