Cold Great Basin Low brings light upslope snowfall to the high country Tuesday……Another on the way for Thursday….Then a fair warm spring weekend and beyond as MJO on the Move!


3-25-2021 Update

No change in our weekend outlook:

Addition to the outlook is a system that appears to be deepening a bit more over the Northern Great Basin Monday. Not enough to bring any precip. However, enough to bring some temporary cooling Monday to this weekends warm up. Although the cool down will be associated with moderate wind Monday,  by Tuesday and Wednesday, highs will be back up into the upper 40s Tuesday then 50s Wednesday.  GFS and ECMWF has snow producing storm for about Easter Sunday through the following mid-week.  The MJO does not agree.  (See below)


It will remain colder than normal through Thursday followed by the first significantly warm weekend thus far this year…..

Lots of breezy periods along with chilly weather, the next few days.

Our weather pattern seems to be shifting to more of an inside slider pattern or far west slider pattern which does not hold much hope for any meaningful snow storm’s. This looks especially true through the first few weeks of April. However, there will be periods of warming, cooling and wind, with interior type storms that would produce mainly light accumulations. (1-6 inches)

I think that anecdotally,  it is now fair to say we are looking at a significant dry water year this year with precipitation in and around the 50% to 55% of normal range by April 1st.

The Dweebs note that La Nina has weakened significantly. So the MJO will be on the move now and that means that important changes to the weather across the CONUS.

The updated seasonal forecast will be out in a few weeks for Summer.

The one that was initialized March 1st, showed a more normal monsoon season out west, and a warmer than normal Summer. The update will be will be out in a week or two. I will have that then…

Bye for now……………


MJO and CPC  discussion:

Attended CPC discussion this AM.

There is a robust MJO that is moving through the Indian Ocean, currently Phases 2 and 3, then on to the Maritime Continent Phases 3 and 4 where it intensifies.  This means that our cold weather is coming to an end this weekend and warmer weather is expected on into next week. In March, MJO phase 2 and 3 are showery and cold here in Mammoth.   By the 27th, MJO is in phase 4, which is warm and dry here in California in April. The MJO moves through phase’s 5/6; April 1st through the 5th.   The “bias” again is Warm and Dry.   Thus Spring Skiing next week look pretty good through the 5th. High temps in Mammoth may rise to the mid 50s this Sunday.

Of note; as of 3-25-21, both ECMWF and GFS week 2 models have a storm coming in from the west about Easter Sunday.  Here is a prime example where the MJO does not agree as it is in early Phase 6. (Dry in April) This is contrary to the week 2 model simulations.  So no verification in the MJO phase space 5/6.   Well see how this all works out!! My bet is on the MJO.

Longer Range shows the possibility of an incursion to Phases 6 which is dry, as well, then *7 and *8 toward mid April which can be cool and showery…..

*Currently, there is little skill in MJO that far out in time.

Remember, a robust MJO within a sector of phase space is not a forecast tool for what the weather will be. This is a tool used in my case to support GFS and ECMWF week 1 and 2 model simulations.




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

Clearing Sky’s Tuesday AM……Next Weather system is looking drier for Friday but may still drop another foot in the upper elevations…..Unsettled weather expected into Monday next week…..

Latest ITV Integrated transport system for the GFS showed a much weakened AR signal this morning with border line weak AR of 250 IVT MAG [KG/(MS)]; while the EURO had no AR signal at all for the same period now. (Friday AM)  So the prospects for an AR of significance is now gone this weekend. Nevertheless, a late Winter storm moving into the sierra later in the day Thursday into Friday may bring up to a foot of fresh snowfall in the upper elevations. The weekend looks a bit unsettled….On into Monday with the chance of snow showers, then a long break between the next storm….

It will be considerably milder this weekend with highs in the 40s and the snow level will be higher…Around 6500 feet Friday….


Dr Howard and the Dweebs…………………..:-)

Up to 20 inches of fresh on Mammoth Mt Today…..Upslope snowfall to end this evening…..Next Storm Monday with another the end of the week…..

Sunday 1`:30PM…..Its later than you think!! 😉

No changes of the snowfall estimates for tonight and Monday as stated below. Winter Weather advisories were hoisted by the NWS beginning late tonight into Monday Evening.

The mid-week period still looks dry, however, as also stated below, the next storm for the next weekend looks much warmer and wetter with the possibility of a weak AR as ITV and IWV are indicting. Considering the slow movement of the storm, amounts may end up in the two foot+ range by week’s end.

More later on that storm…


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


Light beautiful upslope snowfall continued Friday, as the storm system exits Southern CA today into the Desert SW.  Saturday looks blue bird with ridge top winds diminishing during the mid to late afternoon. Highs in Mammoth will climb into the 40s after being in the mid to upper 20s for several days.

With the wintertime Hudson Bay Low absent now and its upstream blocking absent, the progression of short waves have resumed into California. The next upstream system will have a small moisture tap enough for the possibility of an additional 7 to 10 inches of fresh on Mammoth Mt by Monday into Monday evening.  The Town may get 4 to 6 inches.  In the Dweebs extended outlook (subject to change) The following Tuesday through Friday looks dry at the moment, with the next system looking both warmer and wetter, beginning the following Sunday. There may be a weak AR with that storm….  The second half of next week looks milder temperature wise…..


Dr. Howard and the Dweebs…………………:-)