Chilly Upper Trof Axis has pushed east of the Sierra Now and so Sunny skies are expected Sunday…..What appears to be the last shot of Cold Air will Follow Monday….Then its Ridge City for quite a while….

Today is a blustery day in Mammoth with light snow this morning and currently sunny skies. High temperatures today will be in the mid 30s and gusty west winds will make it feel even colder. Lows tonight are expected to be in the teens. There appears to be one more shot of cold air following this trough, between the upper ridge now crossing 140W and the Sierra Crest.  This short wave is dry, but will bring some high clouds, some breezes over the upper elevations and more importantly, a shot of cold air Monday for which Mammoth Mt will be able to make snow day and night. By mid-week,  the upper ridge now progressing toward the west coast will amplify, forcing the freezing level up to 10,000 feet by Wednesday night and over 11,000 by Friday. This west coast ridge is likely to become stationary for sometime. Possibly 2 weeks according to the Euro Model/(Mid Month). I suspect that the week 2 models or during the 2nd week of December, will have better visibility about a change in the pattern for the future.  For the Dweebs…..An important indicator that will give an even longer look down the road will be the RIMM Phase Space, showing where the locations of potential tropical forcing will be. The strength of the signal and speed will be important as well. The speed of the signal can give an indication of what it is.  IE, an MJO, Rossby Waves or Kelvin Waves. A “strong” MJO moving through the Indian Ocean in phase spaces 2 and 3 would  break down the +PNA and help bring retrogression to the pattern that is currently developing for the west coast and eastern US.   At the moment, the RMM chart this morning using the NCEP. (American Models) ,show more amplification within Phase 7 for week 2. This just intensifies the +PNA the following week, so this pattern setting up this week looks bullet proof for at least a week or two.

The good news is that Mammoth Mt received up to 6 feet of snow about a week ago and they are making snow nightly…….:-)  Skiing and boarding is reported to be very good!

 

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

Some light snow is possible this weekend….Then big blocking pattern developing with west coast ridge….There is light at the far end of the tunnel…I just hope it’s no Mirage

Friday AM Update:

Just has a peak at both the 00Z Friday EC and 06Z GFS:

Some interesting deterministic run possibilities….

Both Models continue the trend of the Blocking pattern with ridge in the west. And continuing their trend of the possibility of a bit more moisture for the weekend (Sunday) system for Mono County. I think that I covered it well in the late Thursday afternoon update below.

A new twist though showing up from last night 06z GFS run with some hang back energy underneath the building ridge early next week from the Sunday system. The GFS has this weak low left over or near Southern CA that may just provide an off shore flow and a warm up for LA. However, the ECMWF has a bit more energy that follows the Sunday system early next week that spins up a small closed low on its drack south then off the coast of Paso Robles, CA. That would dampens LA’s warm up and actually put Mammoth in the upper Divergent NE quad of that system, providing some light snow or snow showers anytime between late Monday afternoon and Tuesday night. The system does track south off the SO-Cal coast and so the off shore flow is probably just delayed in this case.  An important point to make is that this all happens as the upstream building ridge that will eventually take over the west coast, later Wednesday into Thursday.

Some New Twists to the longer range:

Earlier in the week I mentioned that the ridge that will be building next week will be top-heavy. This means that a lot more high pressure aloft (Anomalous higher heights) will develop over the higher Latts, and eventually over AK.  +(PNA) & (-EPO). That in its-self reinforces the pattern that has the potential to deliver very cold weather to the Ohio Valley and south to the Gulf States in the 6 to 10 day period. The EPS, AO has that teleconnection dropping to -3.5 standard deviations of normal, meaning that this Block has legs and will likely hold through the 10 or 12th of Dec. However, both EC and GFS are showing some changes there after as the AO goes to 0 (neutral) by the 18th. The WPO area (Bering Sea) has increasing heights at 500MB between the 14th and 18th of Dec. This is signaling a change with the possibility of retrogression of the upper west coast block allowing CPK air (continental polar) air mass to back up over the far west. (Cold)  More later…….

 

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I Just looked at the last few runs of the GFS and EC (American models) and Euro for the weekend. The Trof that is forecasted to come through this weekend is holding on to a WSW flow better in the GFS as compared to the ECMWF.  This is being reflected in the Models QPF.  The EC just brings us a dusting while the GFS suggests possibly 4 to 5 inches of snow over the crest, out of .3 to .4 inches of water.  The 18z GFS is showing higher QPF amounts as compared to its previous runs.  What ever we do get, the ratios of snow to water is going to be pretty high. Possibly 13 to 1.  So some light powder to begin the new week. This will be a windy system for the upper elevations and breezy for the resort levels. It will also be a cold system with temps at 700MB (10K) lowering to -8c to -10C on Sunday. Not all that unusual for early December.

Long Range:

I have beaten this dead horse enough so I will leave it alone for a while and concentrate on the Inter-seasonal outlook.

Today the ECMWF EPS 46 day weekly’s has updated. All I will say for now is that its long-range teleconnections are encouraging!

Here is a brief summery of what I have found out.

  1. The Current negative phase of the Arctic Oscillation turns Positive after the 18th of December and trends more than 4 standard deviation’s above normal by January 7th. So Lower pressure develops over the Arctic which can lead to a more progressive flow across the CONUS. (US) At the moment we are headed toward a very blocky pattern across the CONUS next week with a -AO. This is usually dry for California in a La Nina.
  2. In the same time frame, “Early January to mid Jan, the EP turns very negative, meaning a strong block over Alaska. A strong block over AK with a -AO is dry for California. However, a +AO with a -EPO could be wet for the West coast. The PNA which is positive now will trend negative between Christmas and New years,  while the WPO become negative IE (Blocking over the Bering Sea), toward the end of the year. This suggests Trofing along the west coast toward year end, and a block over the Bering Sea could be a wet west coast pattern. These teleconnection patterns work together and offer various solutions.  My sense is that we will begin to turn stormy around Christmas with several  period’s of snowfall up to about mid of January.  I am just using teleconnections, but that is all I have to work with at this time.

Dr Howard and the Dweebs………………….:-)

 

 

Radical Teleconnection Pattern of +PNA…-AO…-NAO…and evenually-EPO pattern setting up across the Western Hemisphere….Arctic to open up for Bitter Cold Outbreak for the East Next Week…..It will be Ridge City for Much of California after this weekend….

I can just hear it from the Ohio Valley to the east coast from Weather Lovers that like the cold and extreme weather yelling…..The Vortex….Please!  However, what is shaping up for the Eastern CONUS is nothing short of a Polar Outbreak on Steroid’s during much of at least the first half of December. Once snow cover gets established in the northern part of the east and Ohio Valley, the Feed Back begins…. Of course when the Polar Vortex (Hudson Bay Low) is well south of its normal position, the west coast ridges up with vengeance. This according to the GFS and EURO is a strong blocking pattern in the making for much of the west coast next week…. Your going to hear about Eastern Cold in the news and our storm for this weekend looks doubtful at best.  This may be part of a 21 day cycle…..Stay Tuned!