Weak…..Fast moving Closed Low to bring light amounts of Snowfall to the Eastern Sierra this afternoon into Monday….Low is tracking further off shore which will impact snow fall amounts……Arctic Air retreats to the north as AO goes increasing positive….This will be the last storm of 2019….First week of January looks dry……

12/30 7:50AM


Partly Cloudy today with a chance of light snow showers.  Very light if any accumulations today….


Mammoth Mt reports 1 to 2 inches of new snow over night..


Our weather system was just too weak and too of shore to do us any good…

Expecting a dry week ahead….With clouds and wind at times..


The Dweeber….


Here is an update from the Dweeb Report on the forecast for the small year end storm that is expected to bring up some 2 to 6 inches of snow to the high country over the next 36 hours…


Here are the bullet points that shape our snowfall estimates….


  1. The weather system, a small closed low, will track a bit further off shore.
  2. The system will track well south of of Southern California and turn east near the Cedro’s Islands off the coast of Baja.
  3. The speed is a bit quicker in that is will not slow as much as it approaches the CA/Mex Border.


All considered, the front or main area of Upper Divergence is only expected to bring some .20 inches of precip over the crest. 1 to 3 inches of snow…….The upslope portion for the high country is weaker because the low is further off shore with only some 1 to 3 inches expected through Monday evening.

So the snowfall that is just beginning in Mammoth will end Monday evening. Amounts are expected to tally some 2 to 6 inches between the top of Mammoth Mt to the lowest elevations of the Town.


The Medium Range is shaped by the teleconnection of the Arctic Oscillation going strongly positive. This causes more low pressure to become bottled up over the Arctic and Canada, so that jet stream migrates to the north, especially in the far west like CA.

This is expected to be temporary, as the AO teleconnection will trend negative later week 2 and open up the gates to more storminess out west. Even with the upper jet to our north next week, we will not be without interesting weather. I expect some windy weather later in the first week January. The progs show a NW jet to the north of us….

As the AO becomes negative again toward the 8th of January, along with other teleconnections,  support more storminess out west. The EPO becomes significant, as the negative phase of the EPO will trend to drive the upper jet south again into CA. by a blocking pattern. This looks to be robust pattern change, one that could be quite stormy with a lot of snow in the high country. It looks to be a cold pattern with insider slider systems diving into Great Basin, not real good snow producers for the Central Sierra, better for the Rockies…..The pattern shows colder weather ahead as well with gusty winds…Note, this is a wet jet that may affect the northern sierra this weekend, but iffy at best at the moment.  It would have higher snow levels and strong winds


The MJO:


O’ Boy!  There are so many interference’s coming about with the MJO in the weeks ahead. Tropical Storms….Easterly Rossby Waves, a significant westward moving Kelvin Wave, and of course the on-going low frequency -IOD.  It should be an interesting update from the CPC, New Years Eve!!

PS, it has been a long time with out a significant El Nino…


Another update around New Years Day…



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









Cold Weather to persist through Christmas and the day after with Snow showers….Milder Temps over the weekend…Then some more snow shower expected Monday the 30th…No Major Storminess through the New Years day…..

12-25-2019 Update 9:45PM

A cold upper low was located west of Paso Robles at this time and will slowly making its way south down the coast. The Eastern Sierra near Mammoth Lakes will experience some light snowfall tonight into the morning hours. Amounts will be light., 1 to 3 inches.

However, the Owens Valley is expected to be hit hard with snowfall overnight and throughout the day on Thursday. Winter Weather Advisories are hoisted by the National Weather Service  beginning at 10:00PM tonight through Thursday at 10:00PM.  the forecast from the National Weather service is calling for 1 to 3 inches over night and 2 to 4 inches Thursday….  Travel is expected to be difficult.  If your heading south on 395 Thursday AM, be sure to check road conditions and carry chains.



Mammoth Mt Picked up some 17 inches of snow from the last storm system. Now cold snow showery weather to persist through the 26th.  Short wave ridging will answer the call for some fine fair weather both Friday and Saturday.

The chances of a major storm over the next week or two is not high as the AO (Arctic Oscillation) goes into to its positive phase. That effectively keeps Arctic Air bottled up well up into Canada and Alaska. There is some sign that the AO will weaken and go neutral  during the 2nd week of January.

You may notice that our latest series of storms have split south with most of the energy going into Southern CA  and Northern Baja. Our snowfall from the last system brought about a foot over Mammoth Mt with another 5 to 7 inches on Monday. The 5 to 7 inches was from upslope as cyclonic flow moved east to the south of us.  This pattern was for told in my October 22nd post as I analyzed the CPC Winter Forecast.  SEE: https://mammothweather.com/page/7/

Unimpressive front falling apart today and this evening……Upslope snowfall Monday coming to the rescue….

Noon Sunday:

So far the Front has been very unimpressive over Southern Mono County. However, to the north…Even as far south as June Lake or Tioga Pass may have been better.  The Front is dis -jointed…and will fall apart this afternoon and evening.  The Dweebs are not expecting more than between  2 to 6 inches from this front now at the Village.  A bit more is possible over the crest and especially to the west.

The Good News is that tomorrow looks to be a more active day as the upper level system will develop a closed center and will begin to veer the upper flow SE to eventually NE. Southern Mono County does very with upslope because of our topography. Upslope snow will begin in the morning and continue through Monday night. Several inches will fall over the Town and Mammoth Mt. 5 inches+


More Later……