Archive for year 2016

East Asian Jet Extension well in the models now with Best Storm Cycle probabilities for the Winter of 2016….AR Event Saturday PM to supply plenty of juice for the Pump….

Saturday AM:

This will be brief with a more detailed update later today:

Looking at the all the guidance, and if it is correct….we are going into one protracted storm cycle that may rival the “Miracle March” of 1991….. over a 15 day period…..

 

More details later today….

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The Dweebs have been on family leave with newly born twins to take care of…. Both Jakob and Charlie doing well…..Both boys just escaping the stigma of Leap Day by a just few hours!

When the Dweebs updated some 5 days ago, it was apparent that both the EC and the GFS had come into better agreement and that the MJO was strong enough to bring significant upper divergence well east of the dateline and get the EAJ extended to California. It was a tough one without early consensus. After all, the EC is the better model right!  😉

The Dweebs want to make some important points here that deserve mention:

  1. The “AR” that is forecasted to set up has a long fetch across the pacific. Additionally, it has a double structure that is notable.
  2. The PWAT that is forecasted for late Saturday afternoon by the GFS is +5 sigma which is some 5 deviations above normal. There appears to be about 1.5 inches in the column forecasted.
  3. This is a notable AR and although it is nothing like what hit mammoth in February of 1986 or JANUARY 1 1998, this AR will supply a rich source of moisture for the dynamics to lift when it comes in Saturday night in Sunday AM.  The CRFC “QPF” is about 3 inches of water within 30 hours. This is a hammer we have not seen this winter. The snow level will be tricky as microphysical processes maybe come into play as strong UVM develops later Saturday night. This may be one of those rare 3 to 4 foot snowfalls over night in Mammoth, above 8K, depending on where the snow level sets up. The Dweebs will have time to fine tune this tomorrow Friday afternoon..

Looking at the big picture, there are a series of systems headed into the area beginning Friday. The freezing level Friday is 10K so precip will be rain in town. Then there is the Saturday late afternoon/Sunday system which is the biggy.  Another system will move in Sunday and will end Monday evening. There is another 1.5 inches between Sunday afternoon and Monday night, so another 18 inches over Mammoth Mt is possible along with some 6 to 12 in town. That system Sunday will be all snow. All toll, between Friday and Monday Night…..5.5 inches over the crest, or about 5 feet of snow is possible. Will update on QPF again Friday PM

 

There looks to be a break Tuesday through about Thursday with another system Friday into the following weekend. That system may split some….well have to see. Then another AR is hinted by the GFS about the 13th.  The 10 day QPF from the EC is 7 inches or about 6 feet of snow over the crest. The GFS, 12 inches of water or about 10 feet. Take your pick…..Or better yet how about an average…..

 

The Dweeb forecast of 100 inches of snow over the pass at 10:1 is about 10 inches of QPF. Its possible….we’ll see. The Dweebs did say in the 2nd to 3 weeks of March, although the models are trending to split the upper jet south with southern stream energy heading south of us after week 2.

More later………………………..:-)

After a dry 3 to 5 day period….some light snowfall is possible by Thursday…..Pattern transiting to Active…The 2nd week of March enters strong storm cycle with potential significant AR event in addition to several storms……The Dweebs see “The Potential” of 100+ inches of snowfall During weeks 2 and 3 of March…..

Thursday Night….

 

Working on it………………!

 

Sunday:

Some light rain/snow mix is expected in town Thursday with possibly an inch or two above 9000 feet. It will be cooler and breezy Thursday. It appears that a decent storm cycle is possible to begin later next weekend, then on and off again with several storms that following week. That 2nd week of March looks wet. At this time, it looks to be snow, not rain over Mammoth Mt.

Comment Regarding the MJO:

The GFS continue the MJO strong right on through Phase 8.

But look at what the ECMWF does….

It too has the MJO close to moderate into Phase 8. It may be that the GFS is handling the MJO better this time?

 

Stay tuned to an important update on the MJO this upcoming Tuesday PM:

Here are the two MJO phase spaces being handled by two of the more significant ensemble global models the GFS and ECMWF

Both appear to be of moderate strength and close to a 1 sigma.

  1. GFS:      http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_phase_21m_full.gif
  2. ECMM: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_MANOM_51m_full.gif

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Saturday:

There is a lot of convection going on over the equatorial pacific with several channeled ARs developing early this coming week over the central pacific. What is interesting is that a strong tropical high over the far central pacific will build north into the mid latitudes with the EAJ extending east.  There appears to be a gradual progression of the upper jet toward the central west coast in the 5 to 10 day means.  The system on the 3rd (Thursday)  will bring at least light amounts of precip  as it has a small narrow hose connected to it.   Although the main dynamics are to the north of us, there appears to be a lot of channeled moisture from the SW. No doubt this will be associated with high snow levels and strong gusty winds….

Down the road time wise, the ECMWF shows the upper jet sagging south during the following weekend of the 5/6th…thereafter, several opportunities for some good strong trofs with good AR connections to bring added moisture to the Central Sierra during the 2nd week of March….  Hang on….Winters best is yet to come.

 

Dr Howard and the Dweebs……………………:-)

After a Beautiful Day Thursday…..Breezy, Partly Cloudy Conditions Expected Friday…Then a bit cooler Saturday and Sunday with Breezy Weather at times…..Upper ridge returns early next week…..

Ridge over the far west will weaken a bit after today, allowing a few short waves to bring some clouds, some cooling as well as breezy weather to the high country over the weekend. Daytime highs will still range in the low 50s Saturday and Sunday in town, with lows in the 20s. Winds will gust to 55mph over the ridges at times this weekend. Outside of a few light showers late Sunday, no measurable precipitation is expected…

MJO:  Update 2/25 at 8:00AM

GFS is beginning to trend toward the other global models in agreement with the idea of rapid weakening around the dateline. However there is still some upper divergence associated with the MJO tracking a bit further east at this time. The Classic Westerlies Break Through is very unlikely.

The Dweebs are now looking toward the next possibility of the next series of storms for the high country the 2nd half of March. The idea of a “significant” March 3rd storm is no longer in the picture and will more likely be pushed back to at least the 8th or 9th.

In looking at the “ECMWF Ensemble Prediction System [T639L91]” the 5 day means across North America shows a trend for the current cold Hudson Bay Low and long wave Trof over the east to weaken during the 2nd week of March then shift east. This should open up the current wave length and weaken the semi-permanent west coast ridge. The ensemble model also shows the current adjustment wave, IE, Aleutian Low,  shifting east toward the Eastern Pacific. The resulting 500mb height falls over California will lend to a southward shift in the storm track. (Note: The NCEP Climate Models are all over this)

Although we may see our 1st significant system in Central CA around the 7th or 8th, and again about the 11th, the likelihood of storminess will increase by Mid March, and then possibly thru the end of March, as we say goodby to Winter and look forward to Spring…

Stay Tuned…….The Dweebs have you covered!

 

The Dweeber…………………………………….:-)