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….

Arctic Ribbon on the way to bring serious chill to the high country and provide first Platinum Powder for the Season Sunday night and Monday…..Cold weather will be initiated by strong winds Sunday/Sunday Night….Expect Strong Wind Chill Factors Sunday night and especially Monday AM over upper elevations….Well Below Zero…..

5:25PM Sunday:

Arctic Ribbon coming through now…. In back…very cold air to pour in,  all night and through 4:00AM Monday….

 

Revised 12:15AM Sunday

Winds Gusting to 108MPH over the Summit at the moment….

 

A an Arctic Ribbon will pass through Mammoth by 4:00PM Sunday.  The storm system that has been forecasted to moved mainly through the Great Basin has taken a track more over California now. The main idea is still that no moisture will be entrained into the system from the west. However, this system is so cold, that it will squeeze most any moisture left in existing air mass out of it.  Behind the Ribbon and front will be a period of upslope.  There are lots of possibilities here from strong Mono Lake effect for Lee Vining and June Lake to good upslope snowfall for Mammoth Mt. The action of this pattern change with storms now dropping south over the far west this week will do much to empty the Arctic Reservoir of the Extreme Cold that has built up over several weeks over Central Canada….

Mammoth Mountain may receive some 6 to 8 inches over the crest, 3 to 6 inches at the Main Lodge and here in town some 1 to 3+ inches between Sunday night and Tuesday AM. With snow to water ratio’s of 20:1 expected, true Platinum Powder conditions will exist on Mammoth MT, Sunday night and Monday.  It will be cold Monday AM with lows about 5 degrees in town.  However daytime highs will stay in the low 20s. It will remain windy over the upper elevations Monday and breezy in town.  One more thing….The Wind Chill Factor.  You will need to ware face protection to ski/board Monday as wind chills will range between -15 and -30 over the upper elevations.  This is especially true for the morning Monday for you powder lovers.

The fact that this weather system is coming in further west than earlier forecasted is a very good sign of retrogression!   Odds are, that subsequent storms will now come in from a more westerly direction with over water trajectory, especially by the end of the month of February and Early March.  This means that the likelihood of significant snowfall is in our future over the next two to 4 weeks.

 

Stay Tuned!

 

Dr Howard and the Dweebs…………………:-)