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……………………………:-)