Mammoth Mt Reports 14 to 30 inches of the lightest powder in years!! Snowshowers are expected this afternoon then Fair Saturday and warmer Sunday……

Saturday PM:

Monday’s weak storm is expected to bring 1 to 3 inches with possibly another inch or so blown in up in saddle bowl.

Once again the snow to water ratios will be high….

 

Saturday AM:

Although we have another small system that may bring a few more inches to the high country Monday, the focus now becomes the upcoming MJO induced +PNA pattern and the evolution of the break through or REX block under the +PNA itself.  This is expected about end of the 1st week of January or just beyond….    The various runs of the deterministic GFS and ECMWF are quite fascinating now, and over the next 10 days the excitement will build for California as the actual ENSO induced pattern is expected to bring welcome relief to Southern CA as well as most of CA after four years of drought…..

The Dweebs right here will be in the Club Seats….giving you all, play by play explanation’s, as the tempo builds and the Mid Latitude and Southern Stream evolves…..

 

The Dweeber……………………………:-)

 

Christmas Day Morning:

Fabulous Snow….The Dweebs can hear the hooten and Hollering from Mammoth Mt to the Village…

14 to 30 inches of the lightest Platinum Powder fell yesterday and last night…And very much as good as the Rockies like to brag about!

Today is the day to make some turns…..

The forecast indicates some snow shower action this afternoon as a small vort center drops south…. Then a bit of a warm up Saturday into Sunday before a weakening system brings a few more inches on Monday…….

As we work though the Yuletide season and the end of the year….we begin to feel the effects weatherwise, of the strong MJO over the Maritime Continent.  The convective envelop is so strong that the SOI has gone strongly positive (+30) indicating anomalous convection north of Australia and the Maritime continent….This will be temporary however, as the interseasonal wave continues east over the next 2 to 3 weeks….and then the SOI is likely to return negative with vengeance!

Through the Process:

  1. The (-PNA) pattern will become Positive (+PNA)
  2. This happens as the East Asian Jet retreats as the peddle come off the Upper Jet across the pacific and the west coast ridges up strongly.
  3. This will give us a glorious New Year’s over the far west with above normal temps over the upper elevations and gorgeous weather over Southern CA with highs in the 80s into the first week of January…
    a. Strong inversions will likely develop over Mono County with Pogonip ice fog around New Years Day or shortly after around Lee Vining, Mono City as well as around Lake Crowley
    b. In the eastern half of the country, winter will finally arrive from the Great Lakes to New England. The Strong Subtropical jet will likely keep a lot of the colder air confined to the northern sections.
  4. During the first week of January, most of the height rises will concentrate over Western Canada between BC and the Northern Rockies while California continues its fair-weather trend.
  5. Then the Magic of El Nino will likely develop for California during Week 2 of January.
    a. With the +PNA pattern well established over Western Canada, and as the MJO remains strong into Phase 8….MJOs convective envelope shifts well through the Western Pacific as the East Asian Jet gets the peddle to the Meddle…
    b. The upper jet reaches through the Eastern Pacific “about” the early part of the 2nd week of January as short wave systems are now forced east under the Western Canadian block into Central and Southern CA .
    C. This is what Angeleno’s have been waiting for…..

Happy Holidays…………………………From the Dweeber!! 🙂

Winter Storm Warning Hoisted for Mono County for 10:00am Christmas Eve To 4:00am Christmas Day…..1 to 2 Feet Expected….Platinum Powder Alert for Christmas Eve into Christmas Day….MJO Continues on the Move

Christmas Eve:

QPF has been updated to reflect 12 to 24 inch amounts from this Powder Hound by Morning…

Very cold the next 2 days………….

Nice gift under the trees…..

Ho Ho Ho….

 

Some light snow possible Monday……………Then dry through the end of the year……………..

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Wednesday 12/23/19 – 8:30AM Update:

Latest QPF forecast for Yosemite is 1.00.

So on Mammoth Mt at 15:1 that is 15 inches

At 18:1 at 10,000 that is 18 inches…  We’ll see how it works out by Christmas morning…..

OutLook:

There are a couple of small weather systems that may bring a few inches of snow both Monday and again Wednesday. It then goes dry through the end of the year….

MJO and other curiosities…

  1. The SOI has been weakly positive or weakly negative for sometime now….
  2. The MJO is located crossing from phase 5 to phase 6 today.
    a. With the convective portion of the MJO envelope now moving into the Western Pacific…a more upper convergent pattern should emerge north of Australia, allowing the SOI to become negative again. This should provide for stronger westerlies along or near the equator.  So I expect the SOI to possibly turn strongly negative in the next week.
  3. As the MJO shifts further east through the western pacific….the PNA will become strongly positive providing ridging between the far Eastern Pacific to the Western Rockies then north into Canada. This should cut the precip off over the pacific NW and allow them to dry out.
  4. If the ECMWF is correct in progressing the MJO into Phase 8…high amplification of the western ridge will bring the first cold wave into the eastern sections of the country with the 1st good snow over much of  New England.  In that El Nino is strong and the enhanced subtropical jet is as well, I do not expect the cold to last long over the east as it will most likely get flushed out over the Atlantic.
  5. It is what happens next that is important to California. The Composites show that as the MJO progresses well east through Phase 8 that the EAJ extends east to the west coast again…this time under the block to the north. This will be the first opportunity to get an El Nino related storm track into the southern half of the state between the 6th and the 15th of January.

Dr Howard And the Dweebs………………:-)

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A nice day is expected Wednesday with gusty winds over the upper elevations. I expect the snow to return by Thursday morning with the winds ramping up again.

12+inches over the upper elevations is expected with 4 to 7 in town.  Christmas Day will be partly cloudy and cold with highs in the teens and some scattered light snow showers possible. I do not see any large storms on the horizon between this weekend and the New Year but there is the chance of some light snow early next week.

MJO: The MJO will be the big story that will really change the pattern over the next 2 weeks. As the inter seasonal system moves from Phase 6 to 8, precipitation will end in the pacific NW, shortly after the new year as a Mega Ridge Builds into the PNA sector. It will be what happens later that will be interesting, as the MJO moves from phase 8 to possibly phase 1.  This is where the Pineapple Express will often times set up.

 

More later……

Wet Pattern to continue through Tuesday afternoon with very significant precipitation Totals for the west side and sierra crest…..much colder system to quickly move through Christmas Eve……MJO is making all the right moves!

Tuesday: 10:20AM

Mammoth Moutain picked up 2 to 3 feet of wet snow…..

A break Wednesday withy breezy conditions and cooler then a Platinum Powder snowfall Thursday and Thursday Night….

 

Update at 12:00PM

 

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8:15PM Monday:

Were doing really Well! temperature now 31 degrees at 8200 foot; CRFC just updated with 4.00 of QPF for Yosemite by Tuesday afternoon. The IOP will be from 10:00PM to 4:00Am so bigger snows on the way!. That will be the period of the most intense precip so hang in their baby!

4.00 6:1 = at least 24 inches of cement. But wait!!  The temperature at the summit is 21 degrees!  That’s better much better than 6:1!  One things for sure…the god squad up on the hill will be very busy in the AM.  Just try to sleep-in with the 155 MM Howitzers going off in the morning…..!!!

 

Platinum Powder alert will be postponed until the late AM. Dweebs want to see 4 more runs….

 

The Dweeber…………………………………………………

 

We have had wetter storms than this one, but this is fairly wet.  The nose of the hose hits the sierra tonight into Tuesday morning.  Wet snow will continue in town and not as wet snow will fall on Mammoth Mt.  Actually it is great news for the sierra snow pack as 3 to 5 inches of water is forecasted at snow to water ratios of about 6:1 through Tuesday PM. About 2 feet of sierra cement is expected by Tuesday Evening over the crest.

Winds have been ramping up over the higher elevations, with the freezing level slowly rising as well. The freezing level is expected to peak out at about 8500 Tuesday Midday with a snow level of about 8,000, before falling Tuesday night.  After a break Wednesday, a very cold trof will push through the area causing possible local blizzard conditions. I am expecting 7 to 12 inches of snow from the Christmas Eve storm over the upper elevations….at snow to water ratios of 15:1 to 18:1.  In town, lesser amounts are expected, possibly 4 to 7 inches.  According to the CRFC,  the freezing level is forecasted down to 1500 feet by Friday AM  That’s a snow level of 500 to 0. But of course by then, there will not be much of any snow falling Friday Christmas Day, contrary to earlier forecasts. The system is forecasted to move through….Too fast. Nevertheless, some fine powder will be for the tasting!

Saturday looks Fair into Sunday PM…..

 

A little MJO never hurts:

If you look at the Classic El Nino forced wet weather pattern for California, it is highlighted by the positive phase of the PNA and an extended low height anomaly between Hawaii and the Gulf of AK.  You have to have anomalous above normal heights at 500MB between Eastern Alaska to Western Canada to act as a block.  The westerlies are thus forced to duck under the block and the hyper extended subtropical jet through Baja, helps the pattern pull through CA.  That has not happened yet…..

Will it?

It is sure beginning to look like it.  So what needs to happen?

  1. We need some MJO in the right place. Like Phase 6 and especially 7.   An interesting reaction happens when the MJO moves out the Indian Ocean toward the western pacific. The PNA flips from Negative to Positive at about 130 East. Heights rise along the west coast and especially over the pacific northwest.
  2. If you want to see why I feel that the PNA is getting ready to flip, look at the MJO forecast by the GFS and its track and then look at the composites for January during an El Nino and see the loading pattern for the teleconnection.
  3. The Forecasted MJO:  http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_phase_21m_full.gif

a. Phase 6 composite 500MB Heights in January :            http://www.americanwx.com/raleighwx/MJO/MJO/JanENMJOphase6gt1500mb.gif

b. Phase 7 Composite 500MB Heights in January:            http://www.americanwx.com/raleighwx/MJO/MJO/JanENMJOphase7gt1500mb.gif

 

Timing?…about the end of the 1st week of January

 

For you Platinum Powder subscriber’s, a special discussion this evening on the Christmas Eve storm…

 

Dr Howard and the Dweebs…………………….:-)