Update Tuesday Morning:

I'm going to wait for all the 12z runs to finish this morning before posting.

From Monday:

Sorry for the late post.  I had it queued up for 8:30 and then I got two important phone calls.  Not many changes to the forecast this morning.

If you are going to run one model and hang on each run you will drive yourself crazy.  You need to run as many models as possible every run, and watch the averages and trends.  You'll find it removes a lot of the swings and levels out your forecast.

For tomorrow still expecting a week front to move through that is falling apart and moisture starved by the time it reaches the Tahoe basin.  The wettest model run this morning is the European with up to 2 tenths of an inch of snow along the crest. 

I put these forecasts together before the 12z GFS run comes out.  Taking a peak at the 12z run it barely has any moisture reaching us tomorrow.

Snow levels dropping to around 8,000 feet and maybe sitting there through the day.  We could see a dusting to an inch of snow on the mountains.

For Wednesday we have a break but the winds could really start to crank by late in the day with the strong cold front approaching.  

For the Thursday storms not much of a change today.  A few minor adjustments.  The first is to slow the arrival of the system on Thursday, possibly holding of precip until afternoon.  That also slows the colder air arriving slightly as well.  So we should have snow levels falling to 8000 feet at the start Thursday afternoon and then near 7000 feet by Thursday evening.  This storm is pulling in more moisture off the Pacific with a front that holds together and has much colder air behind it.

Thursday night is when we should see the heaviest precipitation with snow levels dropping well below lake level, even below 5000 feet by Friday morning.  That will help to boost snow ratios Thursday night as the heavier snow is falling.  With the slower movement the showers behind the front may linger through most of the day on Friday.  Behind strong cold fronts like this we tend to get some decent snow showers firing up behind the front that are hard to forecast for totals.

The European run last night did back off on total liquid a bit with high end of 1.5 inches West of the lake near the crest.  The 6z GFS still had up to 2 inches.  Taking a peak at the 12z run it backed off only slightly to 1.8 inches.  So we will have to keep an eye on that slightly drier trend, but this storm could overproduce with the showers behind the front, so I'm not too concerned on the forecast yet.

GFS

Euro

Here is the updated forecast notching the total forecast by Saturday morning down a couple inches from yesterday, back to where they were two days ago.  Still 10-20+ inches for the mountains with several inches possible at lake level.

Much colder air in place for the weekend with highs possibly only in the 20's up on the mountains.  The trend has been fairly consistent in bringing in the next storm by Sunday.

The European model shows a storm for Sunday into Monday similar to the one this Thursday.  A quick hitting cold storm with 1-2 feet.  The GFS has had some interesting runs the past 24 hours.  Some runs show the storm tapping moisture from back near Hawaii and possibly have the jet stream stall over Tahoe for a couple of days.  It keeps us on the cold side of the jet stream and shows some impressive snowfall totals. 

For now we'll stick with the European and 6z GFS runs that just show a progressive storm that hits Sunday-Monday bringing more precipitation and snowfall to the mountains.

We will start the initial snowfall forecast for Sunday on tomorrows blog.

With the trough in place over the West Coast next week we could see another storm move in by next Wed-Thu.  It's too far out to look at specifics, but it looks much weaker than the preceding two storms on the latest model runs.

There is a slight change on the ensemble mean height forecasts beyond 10 days.  They show the possibility of a brief ridge building in the weekend of the 27th.  But then another trough digging into the West Coast the last few days of the month reopening the storm door.

Stay tuned....BA