Heavy Snow Showers possible Monday Night into the morning hours…..Major snow pattern setting up for Thursday and Friday followed by snow showery weekend….Platinum Powder Watch for Friday….Winter Just getting started….just in time for Spring!

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………………………….:-)

Platinum Powder Alert for Friday Morning…..Mammoth Mt Reports 12 to 14 inches of Platinum Powder…..Ratios of at Least 15:1…..Cold Weather to continue with slowly moderating temperatures this weekend…..

This will be very brief for the lack of time this weekend……

 

Cold will continue another day then somewhat milder temps this weekend. It will be windy over the crest due to the upper jet and its Front Right exit region favoring Mammoth.  A Great Basin Slider will come through Saturday night reinforcing the wind as well.  Next Upstream significant system still is in forecast but questions remain  as to how much over water trajectory and for how long it will effect the central and southern sierra.  Looks like amounts will be most significant in the Southern Sierra.   Moderate amounts best bet with 6 to 18 inch range over the crest Monday and Tuesday.  2nd half of next week is main target for best snow producer but too early to forecast at this time…. Pattern will become wetter in March….Hoping for a miracle……..

 

Dr Howard and the Dweebs…………………:-)

Chilly Modified Arctic Air Entrenched over Mono County today with reinforcing shots from the north this week….Cold Showery weather to continue with much colder then normal temperatures as a result…..First real signs of the pacific opening up…First Week of March….

Thursday 2:36PM update:

 

More Modified Arctic Cold today and with the lack of snow cover in town, the cold is beginning to take its toll on the older condominium projects in the form of frozen pipes. This has been reported to me by several condominiums managers today. This condition is likely to get worse, over the next 48 hours.  The problem arises when the warmer weather returns and pipes burst.   This is Mid December weather pattern in mid to late February. Very rare!  If this pattern occurred in mid December, we would be looking at high single digits for daytime highs and lows -15 to -20 below, similar to what happened December 20th 1990.

 

Pattern recognition:   This is the typical cold weather great basin Trof that returns to the west,  before a cold upper Trof retrogrades off shore.  Signs of this are now in the medium range as the next significant short wave digs west off shore, Monday/Night. This issue about this Trof is that the south-west upper flow is not expected for the Central and Northern CA region. Tt is reserved for Southern CA. So the early next week storm is likely to be bigger for So-Cal Tuesday precip wise. Nevertheless, we will still get light to possibly moderate amounts Monday/Night.  Then hang on….!!   Further retrogression is still advertised with good SW flow for Central and Northern CA beginning next Thursday or Friday. This is for March 1st or 2nd and that storm is a slow mover that could hang around all weekend according to the latest model runs….!

 

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Our Arctic front came through as expected with light over night snowfall and strong wind chills over the upper elevation this morning. IN town the streets were covered with snow of the squeaky kind. Temperatures will be in the teens for the most part today with over night lows near 0F.

Our Great Basin upper trof will park over the Great Basin for most of this week.  Next week as we wrap up the Month of February, retrogression of the long wave upper high and trof will occur as advertised. The trof axis will be fairly close to the west coast and so limited over water trajectory will continue snowfall here in the high country this Thursday the 22nd. More importantly…. Next Tuesday the 27th the subtropical jet will become confluent with the polar jet for a better storm at that time. However, so far, the PWAT is still not all that impressive from this distance in time. That may change later.

More importantly, if we believe the week two guidance on the GFS for this Mornings 12Z run, a wet fetch does emanate from Hawaii as the Pacific opens up, with a stronger subtropical jet at 250MB pointed at Southern CA. The PWAT is rich on that set up for about the 5th or 6th of march…..Stay Tuned….We may still have a water miracle during March….