Archive for March, 2021

Spring weather has Sprung with a warm day expected Sunday….Dry Cold Front to bring Cooling and Wind Tonight through Tuesday with another warm-up Mid Week……Easter Sunday and beyond may be unsettled……

3-31-2021  10:50AM  (UPDATE)

High pressure builds over CA today with ridging into Friday.  Above normal temps are expected into the weekend with highs in the mid to high 50s in Mammoth with lows mostly in the 20s. Winds will be light today and Thursday.

The weekend weather shows periods of high clouds as SW flow develops ahead of an approaching Trof Sunday. Little change in temperatures are expected through Saturday. 500MB height falls begin Sunday as a positive tilt Trof elongates SW Sunday with a split that spins up a closed low off the Central CA coast Sunday. 250MB upper jet forces moderate to strong winds over the upper elevations Sunday. Sunday will be a bit cooler than Saturday. Winds will further increase Sunday night and begin to work there way down into the lower elevations. Jet”O”Geneses  develops Sunday into Sunday night as some weak phasing with STJ. Thus subtropical moisture “Advects” into California Sunday Afternoon into Monday AM. A cold front moves through the Sierra Monday AM with wind, cooling and showers. As the upper Trof pushes through Tuesday evening, clearing is expected Tuesday night with flat ridging to follow Wednesday into Thursday next week. (Fair Weather).


Longer Range: There is less certainty with the storm for the end of next week.  Weather systems are appearing to slow down now and become more cut off.  It may be that the end of next week’s storm is pushed back to mid month as our wet season winds down and another drought year is becoming more inevitable with each passing week.

April 1st water content for the Southern and Sentral sierra will show 51% to 55% of normal, although Mammoth Pass added substantially to that with the moderate AR, late last January.

The storm early next week may drop up to a foot of snow over the crest by Tuesday evening if everything works out just right!!


Dr Howard and the Dweebs…………………..:-)


It was a beautiful day in California Sunday. Temperatures were above normal, (50s) and it really felt like Spring! The upper ridge aloft will give way to a system tracking through the Pacific Northwest tonight and into the Northern Rockies Monday. The Upper Trof will bring wind and cooling for the Mammoth Area Tonight through Tuesday. Tuesday look to be the coolest day with highs in the mid 40s with lows in the upper teens and 20s Wednesday AM.  By Wednesday afternoon, ridging is back and it builds through Friday, Highs will reach the upper 50 to low 60s, Thursday into Friday.  By Friday night, winds increase as a Trough deepens down the coast . This may bring precipitation back into our area as early as Saturday night or Easter Sunday. It is just too far out for any certainty. By week-two as the MJO heads into phase 7, the odds increase for a significant unsettled pattern change, the week following Easter Sunday.


Dr Howard and the Dweebs…………………….:-)

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…………………..:-)