Platinum Powder Watch for Friday…12 inches or more at 15:1 or better….Good possibility for epic weekend for “Platinum Powder.”

Our weather front brought between 4 and 5 inches of snowfall to Mammoth Mt today.  Light fluffy snow!  Second part of the storm is currently developing as weather front has pushed through and somewhat fallen apart.

Upper Trof has now pinched off a closed center which is located over San Jose at 01Z TUESDAY and proged to move SE down the coast and just inland. Looks like a great set up for wrap around upslope snowfall as shown by the 18Z Monday Arizona Regional WRF Model. This model highlights forecasted composite radar which shows the motion of the simulated echos well. So some great upslope is expected this evening from Nevada as a deformation sets up to the north of us and slowly shifts south over night. Amounts will probably exceed what we already have or some 4 to 8 inches additional is possible by 7:00AM Tuesday AM. Then snowshowers will taper off during the rest of the morning…

Expect a break Tuesday night and Wednesday with a chance of snow developing late Wednesday night.. Wednesday’s winds do not look particularly strong but will pick up that night. Highs in the 20s


Then we have to deal with possibly of the biggest storm of the winter Thursday and Friday…..

Why do I say that?

Here is why;

  1. The storm has very good over water trajectory
  2. By Thursday afternoon heights at 500MB are forecasted by the ECMWF at 518DM west of the Columbia River
  3. A very large pool of -35c at 500MB is associated with this system stretching for the Vancouver island to Tahoe Friday AM. Its big cold tap is from a pool of -45C at 500MB,  located over the Beaufort Sea north of the Arctic Circle. The cold air eventually invades Mammoth Friday into Saturday AM for some great “Platinum Powder” and lots of it!…
  4. This is a slow-moving storm. It will take at least two days to get through and it will come through in waves.
  5. This is a classic Snow Pattern, especially for the Northern Sierra. The air mass it is coming into is already cold and so there will be a lot of snow in places that do not usually get a lot of snow at one time like RENO and Carson City.  Today guidance suggests 4 to 8 inches possible in those valleys by Saturday AM according to the NAM FOUS today.
  6. Winds…..The big winds arrive Thursday night with peak winds Friday morning. With the very dry snow and lots of it, combined with high winds….blizzard conditions are likely to develop with possible road closures, sometime between Thursday night into Friday along highway 395.
  7. Total snowfall accumulations 3 to 5 feet between Thursday morning and Saturday PM
  8. This will be an epic weekend for “Platinum Powder”.

Longer Range:

Based Upon both ECMWF and GFS; PWAT…500MB heights and 200Hpa winds. Opportunities for Subtropical jet and then both polar and subtropical jet confluence. (March 8th thru 14th and 11th thru 13th) Potential AR Events?

These will be warmer and wetter systems…still snow over the upper elevations….

Hang on…..The Dweebs said that winter would arrive in late February and March…….:-)


Dr Howard and the Dweebs………………………….:-)