Mammoth Weather

4/14/2023

Global models this AM continuing to forecast periods of warming, cooling, periods of wind and periods of snow showers for Mono County the next few weeks. No major snow producing storms are in the forecast for Mono County.

Thursday’s weather system is now in the Rockies and high pressure aloft is building in today into Saturday. A warming trend is under way today with highs in the 40s vs yesterday’s upper 30s.  Highs will jump into the low 50s on Saturday and a resumption of the great thaw of 2023 will return this weekend. However, being that this is April, there will be plenty of cool spells that will alternate with our warm spells. A pattern of warmth on weekends followed by cooler weather during the week seems to be the way the weather will trend. Winds will be the “lightest” tomorrow Saturday for Owens Valley while highs will return to the low 70s. On Sunday, both Mono County and Inyo County will experience more wind. However, high temperatures will warm further as well.   The wind on Sunday is the harbinger of more trofing next week that will bring a good 15 degrees of cooling to our high county by the following Tuesday. Highs in Mammoth will cool to the mid-30s with teens returning by Wednesday AM.   There may be snow showers, especially on Tuesday AM and again Thursday.  This pattern is highlighted by the forecast of the upper jet axis remaining mostly north of Mammoth. This ensures that most of the precip will be Tahoe Northward next week. The Northwest Jet is a pain in the @##.  Upper convergence favoring the Central Sierra often makes for pesky winds, and these are likely to be with us, on and off, Monday through Thursday next week.  At this time, the remains of this pattern may push through by next Friday, leaving a calm warmer weekend for the 22nd.

Don’t forget about the Lyrid Meteor Shower; (late evening to dawn on the nights of April 21-22 and 22-23)

Dr Howard and the Dweebs…………………..:-)

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4/13/23

Its Springtime in the high country and Spring Trofs will continue to progress through the west coast, until Summer Arrives.  Wind….Showers and cooling will alternate with warm periods as well. Although a moderate MJO is getting ready to pass through the infamous phase 7/8 into phase 8, now that it’s Mid-April, the most significant influences will most likely be up into the Pacific NW. This also includes any significant Atmospheric River action. This is not to say we could not get a meaningfull snowstorm before the end of April and even May. However, it is unlikely that we will experience anything like this past winter.

The MJO of late February into March was almost off the charts in the RMM Phase 8 sector. (see graphics) This was instrumental to the many AR’s that affected CA this late Winter.  It is a known fact to many inter-seasonal forecasters, that the Madden Julian Oscillation, can modulate the Westerlies in the right location and extend the East Asian Jet Stream well into the west coast and bring very wet weather to wherever it hits. In this case, it has been California. However, the media’s tout of 32 or 33 ARs this wet season is over blown.

Scripps Institution of Oceanography at US San Diego’s intent, I believe, was not to create an over blown character to describe this winter’s series of AR’s. As an example, the AR 1 (weak) and AR 2 (Moderate) are not often Hugh storm producers for the Sierra. Also, one must remember, that you can get an AR of significance, however, without any dynamic lift, you do not get much more than light precipitation at best. It’s like the Monsoon moisture argument. You can get a strong monsoon surge of moisture and get little rainfall without dynamic lift.   It is very important to remember that for the Sierra, the AR needs to be at least Category 3 or stronger for a major impact, as well as extend into the Sierra itself. Some of these smaller ARs barely made it to the coast this Spring, let alone through the Sierra.  So, 32 ARs?   Hype Hype!!!  Scripps only puts out a notification of an AR when a Cat 3 or greater AR is expected.  See and book mark this link for more information on the Atmospheric River.   https://cw3e.ucsd.edu/iwv-and-ivt-forecasts/

4:15PM 4/6/2023

New Update from DWP on the Snow Course Survey.

The snow course is an average of 10 points over about 100 yards (one of which is next to the snow pillow) and the average of those 10 points is 104.7 inches of SWE. 

Comment:   So for the record, the update says, that the Mammoth Pass receievd an average of 104.7 inches of water.  

That is now, 17% greater than the Winter of 1969, the previous greatest water year on record!

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Today, Thursday is a milder day. There will a be storm that will move into Northern CA and the Pacific NW Tonight and Friday. Wind and Clouds are slated for Mono County and a chance for some light showers Friday morning. Saturday will begin a warming trend into Monday as a warm upper ridge builds over the Great Basin and Rockies. Freezing levels rise to 12,000 Sunday night at the peak of the warming. Snow melt will provide some local pooling of water on Old Mammoth Rd and Mid-Town. Some minor flooding is possible over the lower elevations of Mono County, mainly below 7000 feet. Highs in Mammoth may climb to the low 50s Sunday and Monday.
Again, the Dweebs are emphasizing to locals to locate their Propane Registers now and shut off switches, on their buildings. Make sure they are clear of the snow and ice above them. A Rapid thaw is possible this weekend into early next week. Any heavy snow and ice dams above registers will be a hazard.

Longer Range:
The weather next week beginning Tuesday into next week looks breezy/windy and cooler. Slight chance of showers Wednesday night into Friday. The CFS and EURO model trends in the longer-range show cooler than normal weather the remainder of April.

Interseasonal thoughts:
Considering the snowpack is at record levels, The monsoon season here in the Sierra is likely to be delayed this Summer and may not materialize at all. It will take well into August to melt the current snowpack over and near the Sierra Crest. Snow cover affects both local temperatures and convection. Our early Summer may be cooler than normal.

El Nino is expected to build well into the Fall. SSTA’s are expected to be exceptionally above normal over the far Eastern Pacific this Fall. A bigger hurricane season is possible for the Tropical Eastern Pacific and weaker than normal hurricane season is expected for the Gulf of Mexico and the Western Atlantic.

Dr Howard and the Dweebs……………..:-)

4/5/2023

Historic Water Content On The Pass 102.7 247% of normal.  – 16% greater than the Winter of 1969 (86.5). 

The Southern Sierra is 305% of normal; April 1st

Historic WInter by a long shot!

The Winter of 2023 beats them all here in Mammoth Lakes

According the DWP; the following in order, are the biggest Winter’s here in Mammoth Lakes, measuring the water content on Mammoth Pass.

1. Winter of 2023    247% of normal April 4th      102.7 inches of water
2.       ”        1969    203%                  April 1st        86.5 inches of water
3.       ”        1983    196%                    ”                  83.7 inches of water
4.       ”        2017    193%                    ”                  82.3 inches of water
5.       ”        1938    176%                    ”                  75.2 inches of water
6.       ”        1952    173%                    ”                  73.7 inches of water

Of interest is that the winter of 1952 was not as impressive here in Mammoth as 5 larger winters.

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4/4/23  (Always click on header for correct format)

Updates on our short, medium, and long range:

Our cold spell will shift eastward tomorrow with the beginning of milder temperatures.  High temperatures will climb into the 50s by Easter Sunday and warm further that following Monday.

A weather system will pass to our north this Thursday night into Friday morning bringing some clouds and wind.

It is interesting to note that the long wave ridge bringing us our warmup over the weekend will develop over the Rockies. It forces a short wave well off shore to become positive tilt and pick up a lot of subtropical moisture from the SW. During the Winter, a vigorous storm would pick this up for a major storm here in the high country. Not this time, as although there will be periods of cloudiness, it will be a milder weekend and dry! This is a case whereby you can have plenty of moisture but without any lifting mechanisms, you do not get precip. The IWV and IVT plume forecast from the GEFS shows this as a weak “AR” this weekend.

Longer Range shows a few transitory systems to our north mid-week next week with more wind and clouds for our area. Those storms will mainly affect Northern CA and the Pac NW. Beyond mid-week next week, the weather looks to return to unsettled, with the possibility of storms being in the light to possibly moderate snowfall range. The pattern may continue through that following week. The Dweebs want to stress that Northern CA will likely get the brunt of most of these weather systems that may affect our area the 3rd week of April.  Light snow  (1-6 inches)   Moderate Snow (6-18 inches)

EL Nino:

It is expected that EL Nino will come on moderate to strong later this year, like late Summer and Fall. El Ninos often provides for a warm dry Fall. Most wet El Nino’s tend to bring winters that begin later in the year.
Not all Strong El Nino’s are wet for Central CA. The Modoki El Nino in the past had produced some dryer than normal winters and several winters that were 80% to 95% of normal precip. But a few were wetter than normal. There is no indication that this will be a Modoki El Nino at this time as SSTAs are already much warmer than normal off the Central American coast. The Modoki is characterized by warmer than normal SSTAs in the Central EQ Pacific, and normal to cooler than normal off the Central American Coast. Currently, we are in the Spring Barrier for prediction. Better ENSO prediction will occur this Summer of what this El Nino is likely to be.
El Nino from a teleconnection favors a positive height anomaly over Western Canada and offshore. (+PNA) La Nina (-PNA) favors a negative height anomaly in the same area. High pressure aloft over the far west is usually associated with drier than normal precip for the Pacific NW and “Only When” the upper jet gets strong enough across the pacific that it can undercut the ridging well to the north. When the upper jet gets stronger later in the year, its undercuting favors Southern California the most. Stronger El Ninos can affect our state further north as well. One comment about Strong Wet El Ninos in California is that their AR’s usually have higher freezing levels and thus can bring more rain to higher elevations.

Dr Howard and the Dweebs……….:-)

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4/3/23

A return of cold weather occured today. Monday has snow showers and strong winds over the upper elevations. High temperatures have returned to the 20s in town and lows at night in the single digits and teens. A few more inches of snow are possible this evening.

Of interest was the Katabatic winds that developed over Owens Valley yesterday. High temps were some 32 degrees warmer as NW Flow under the Front Rt exit region provided Adiabatic heating and down sloping for the Bishop area. Today, Bishop will not be so lucky with highs in the 40s and strong winds.

I wanted to remind everyone that early Spring is still a time for significant snow producing weather systems.  However, the Global Models will become very tricky because of the large-scale differential heating beginning to take place, changing thermal gradients from the oceans to the continent. (CONUS) Heating over the West tends to increase the strength of the upper jet on the east side of Trofs which tends to shift these lows more to the east sooner. Northern CA does better precipitation wise as we get further into the month of April. WX systems tend to Cut Off from the westerlies when they approach the CA Coast. Thus more blown forecasts for the Weatherman, the further we get into Spring!  😉

Latest Global models are touting a storm for the Central West Coast the middle of the month. The odds are higher for significant snowfall for the Northern Sierra.

The New 12Z American Models have a significant long wave Trof developing just off the west coast early the following week which deepens further between the 12th and the 17th.  Since the European 360 ENS is not out yet….. The deterministic run suggests a modest system for the Central Sierra, the middle of next week. The Euro is weaker next week with the mid-week system, than the GFS for our area. Thus….It’s too early for a judgement call on whether we are going to get clobbered again later next week. I would say that the Northern Sierra has a better chance at this point.       Stay tuned…………….

Of Importance is the current situation on the propane systems on the structures in town. As many locals know, we have had two major propane related explosions already. Back in the 1990s, we had a major issue with propane explosions in town and the TOML changed the building codes to help compensate for the issues at that time.   This winter has been highly unusual, to say the least with roof shoveled snow raising the snow levels to the roof base in some cases.

Unusual Winter:

1. All-time record April 1 Water on Mammoth Pass since 1920 according to the DWP
2. Being that the winter was so exceptionally cold, there was little snowmelt in town which allowed the snowpack in town to grow up and be record setting.
3. The many AR storms were mostly snow in town.
4. All this has challenged the snow removal systems of the TOMLs, and pushed property owners of single-family residents, condominium projects, commercial and apartments to financial extremes in many ways.

From a propane hazard issue, all property owners should look around their structures and find the reflector on their building. The reflector of various colors is located up high on the wall, which is above a small shed, covering the propane regulator and shut off valve.  The reflector would most likely be located on a wall away from the natural roof shed area.  Find the reflector, make sure the regulator, and shut off valve are not buried, being careful not to compromise the regulator when freeing that area from snow and ice. It is always best to have a professional do that kind of work. If you smell propane get out of your structure and call 911 immediately.

For more details, youtube has a great video made by the MLFD for all the details. Go to YouTube; Search and type in MLFD. the Video is there.

Dr Howard and the Dweebs……….:-)