Friday 11:55PM

This is one ugly transition in pattern.

Apparently, we are going from one dry pattern to the next.  Time for Dan McConnell to start doing his famous snow dance….Backwards……


Friday 22nd

Overall pattern is unchanged for the next week with an upper ridge just off the CA coast. Although this pattern will keep major storminess out of the Sierra, the ridge this time is much less amplified and so there will be considerable high cloudiness and mid level cloudiness at times. Some weak forcing may allow for some snow showers/light precipitation into early next week.   Highs temps will be in the low 50s with lows in the teens and 20s….  There will be periods of gusty winds over the crest from time to time….

Week 2 (between the weekend) of New Years and the following weekend still looks a bit more promising at this time for a snow producing system according to the European Model.


The SOI has gone negative for 12 days now; a signal that will help weaken the ongoing La Nina.  According to the CPC, SSTA’s over the Indian Ocean are forecasted to warm over the coming months and promote more convection in that area. Strong convective forcing associated with MJO between 70 east and 120E is teleconnected with a negative PNA or troughing over the far west CONUS, or Eastern Pacific. This is the MJO RIMM Phase Spaces 2 and 3.

The Dweeber…………………………



A cold northwest slider brought light amounts of snowfall to Mammoth as forecasted. Mammoth Mt at the Main Lodge site showed a good .40 water equivalent at the Main Lodge. Although winds were strong yesterday and there was a lot of blowing and drifting, Mammoth Mt reported 3 to 4 inches storm total.  However, snow to water ratios suggest a conservative 4 to 6 inches overall, with at least 6 inches of Platinum Powder over the crest, as temperature’s within the storm were between 10 and 15 degrees at 11,000 feet. A rough estimate of snow to water ratios within this temperature range over the crest suggest snow to water ratios of at least 15:1.

Looking forward:

Models continue to struggle with the week 2 period. However they seem to have the same short wave inside-slider system proged to come through between next Wednesday and Thursday, between Christmas and New Years. This has the potential to be a similar scenario to the system we had yesterday with a light snow producing storm that ended up as a NW slider. Details in this system will no doubt be forthcoming by Christmas Day.

Beyond this system we get into the Week 2 period in which the most popular global models handle the pattern different. The idea of a meaningful storm is still possible during the week two period. However its certainty is obscured by the fact that the models are still not in agreement on a storm in a specific time frame.  As an example, last nights ECMWF deterministic 00z Thursday run showed a meaningful storm between New Years Eve through the following Wednesday while the American models do not develop a similar pattern until the following weekend of the 6th. Until we get more model consensus, within a specific time frame, we will have to stay with the same dry forecast. That is, until which time, that consensus happens.  It may happen in the next few days or it may not until much later.  The forcing mechanism’s behind the “Big Trof” in the east and the ridge out west has several teleconnecting variables. Some are Air-Sea related and some related to ENSO and others related to the QBO in its negative phase.

In the meantime, we can expect moderating temps here in Mammoth with daytime highs reaching the upper 20s today, climbing to the low 50s this weekend into Christmas Day. Nighttime lows currently in the single digits will climb into the upper teens. We can expect the upper level winds to gradually diminish over time as well. Temperature inversions will redevelop this weekend with the freezing level this morning at 3200 rising above 11,000 this weekend. Temperatures will remain inverted with cold in the valleys of Mono County through Christmas Day. Air Qual may be an issue over the holiday.

Next small system is expected about Mid-Week..


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