Precipitation tallies continue to add up….Very Wet Atmopheric River now an event of the past….However….Moderate AR still in the picture through Wednesday AM…..Lots more snow coming!!

As of 8:45 am Monday, Mammoth Pass has picked up 7.96 inches of water since AR # 2 started Saturday. Add that to AR #1 of 8.44 and you get about 16.5 inches of water. That a lot and there is possibly another 6 more inches to come by Thursday Night!.  Fridays storm is not in the future anymore, so the extreme amounts of 25 to 30 inch’s are unlikely now.  However, 20 to 25 inches is still in the picture by Thursday night of this week. Considering that about 43 inches of water is average,  we are well over 1/2 of our winters worth precipitation when you add October, November and December! We are possibly closing in on a full Winter’s worth quickly!!

WX Discussion:

Latest Satellite water vapor motion shows an intense upper low west of Washington and Oregon coast.  This upper wave according to the models will be replaced by the larger scale cyclone itself, as it moves eastward. The timing of this feature is to move it through Mammoth Lakes Tuesday night with an intense vertical motion field. Thus the main IOP, (Intensive operational period) will be Tuesday night into Early Wednesday morning where snowfall rates may be in the 2 to 4 inch per hour range for a time….  The Town of Mammoth at the 8000 foot level is likely to experience 3 feet to as high as 5 feet of snowfall between Monday AM and Thursday afternoon. Again the heaviest snowfall rates are likely Tuesday night…..

Outlook: We are still expecting a partly cloudy but fair weekend with high in the 20s. Lows in the single digits. Skiing will be on cold packed powder with deep powder as well.  Mammoth Mountain is likely to have received totals over the upper mountain in excess of 18 feet….

 

Next big storm has moved into the high country with moderate snowfall…..Cold Air trapped in the lower elevations will ensure snowfall well into the afternoon….Rain still forecasted for later tonight through Sunday Night with rain changing back to snow Monday Morning in Mammoth Lakes….

Saturday at 1:30 PM

Here are some interesting temps to show warm frontal snowfall. It will give you a profile of temperatures;

Temps:

Summit of Mammoth Mt  25f
Main Lodge                       30
Village at Mammoth          26
Crestview station               25
Mammoth AP                    25  Moderate Snow
Bishop AP                          31  Light Snow

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The Temperature at Mammoth Lakes this morning has been about 20 degrees and so precipitation is warm front like induced, as warm moist air is being lifted by both the sierra and cold air at the surface. Snowfall will continue and be moderate until the winds pick up later today and mixes it out… Snow may accumulate over a foot in town before it changes to rain.

I just has a look at the Pine flat Dam FMCW S-Band Snow Level Radar. It is currently indicating that the snow level due west of us in the sierra foothills is 9300 feet. So we are trapped in the cold air in the Great Basin side of the Sierra and it is isothermal down to at least the Crestview Station.

When will the snow change to rain? Sometime this afternoon. Possibly as late at 4:00PM. However, there is no certainty in a forecast like that.  Once the winds pick up the snow level will jump very quickly!

After the rain event Sunday and Sunday night, the snow level will come back into town sometime early to mid Monday Morning…..

The Town of Mammoth will receive several feet of snow next week…..

Outlook….

I will have a detailed outlook in my weather letter put together tonight for Monday AM….

Just a hint though shows the storm track lifting north Friday into the weekend….

 

Dr Howard and the Dweebs………………..:-)

Let the Weather Patterns Begin!….Cold Storm 1st Mid Week then Wet and Wild over the weekend……General Quantitative Central Sierra precipitation forecasts of 25 to 30 inches of water EQ by January 13th……

Thursday AM Update:

Think we have had a big winter so far?  Think again…According to the DWP, as of January 4th yesterday, Mammoth Pass was only 101% of normal. However, that does not reflect much of the 7.85 inches that has fallen by 10:00AM Thursday….

 

  1. Mammoth Mt Reporting 3.5 feet to 7 feet of new snow storm total so far….Another 3 to 7 inches is possible today.
  2. At Mammoth WX .com 34 inches of snow has fallen.
  3. Mammoth Pass as of 8:45 AM Thursday, has a storm total of 7.84 inches
  4. Major flood event is forecasted for Yosemite Valley Sunday Afternoon
  5. AR event to begin as snow Saturday morning with snow changing to rain during the late afternoon or evening. Heavy rain is expected by Saturday night with the snow level at 9000 to 9500 feet into Sunday AM
  6. The Snow level will remain above 9000 feet until about mid afternoon Sunday. It begins to come down about 4:00PM Sunday then lower throughout the night and into Monday.

Here are the updated freezing levels for Yosemite from California Rivers Forecast Center (CNRFC)

  1. Sunday  4:00AM    10,000 feet
  2. Sunday 10:00AM     9700  feet
  3. Sunday   4:00PM      8900 feet
  4. Sunday 10:00PM      8600 feet  (Snow sticking at Canyon Lodge then Eastward to the Village at Mammoth over night)
  5. Monday  4:00AM     7900 feet   (Snow sticking in TOML)
  6. Monday 10:00AM    7300 feet   (Snow sticking on Highway 395

Note:   The snow level is 500 feet below the freezing level in a saturated air mass; These freezing level are provided by CRFC.

The Water EQ is still the same; about 10 to 12 inches over the Central Sierra through the weekend and between 6 and 7 inches in the Town of Mammoth. The good news this morning is that the very latest freezing level information from CRFC, for Yosemite, which I use as a guide for Mammoth Lakes is showing that colder air will be moving into our area sooner, like Sunday night into Monday AM.  For those that are interested, compare the freezing level info below in Tuesday afternoons update to what you see above. As you can see, by Monday 4:00AM, the freezing level is some 1200 feet lower!

Outlook:

AR = Atmospheric River  SEE:    https://www.esrl.noaa.gov/psd/atmrivers/

The latest “updated” QPF (Quantitative Precipitation Forecast) for the Central Sierra between 4:00AM today Thursday, through Friday night at 10:00PM the 13th of January is 30.00 inches of Water.

 

AR #2 arrives Saturday AM with a break Monday Night and Tuesday

AR #3 is a smaller AR and the Dweebs believe that Mono County will just get a lot of Snow above 6000 feet.

AR #4 arrives Thursday Afternoon the 12th. This too looks to be a colder storm with it winding down late Friday into Saturday the 14th.

I will have a special update on the longer range this weekend via my Weather Letter….

Dr Howard and the Dweebs………………….:-)

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Wednesday Jan 4th:

1st in a possible series of 3 AR events is unloading on the Mammoth Lakes 24 hour amounts 2.23 inches of water and 27 inches of new snowfall at Main Lodge. There is about 18 inches at the Village at Mammoth.

We are about 1/2 way through this storm…

2nd Atmospheric River will hit Saturday with the peak late Sunday AM. Snow level possibly going up as high as 9500 feet by 10:00AM Sunday. Snow level will come down late Sunday afternoon into Monday.

3rd Atmospheric River may occur next Wednesday through the following Thursday Night. This appears to be the last in the series…The wet pattern ends when the blocking over AK and the Bering Sea ends….which is about Friday the 13th of January…

Your lucky day….the Dweebs still see a total of 25 to 30 inches of Water over the Central Sierra from this storm cycle which began yesterday the 3rd and will likely end by Friday the 13th……

 

 

 

Tuesday 1:45 PM Update:

 

7 day QPF posted by WPC covering period through Tuesday night next week is 22.8 inches.  This does not cover the storm for Tuesday night through the following Friday,  which may be the last in the series….

There is chat about the rain on Sunday.  Here are the freezing levels just released by RFC

 

Here is the latest freezing levels for Yosemite for the subject time frame.

  1. 4:00PM Saturday      8800
  2. 10:00PM Saturday    9300
  3. 4:am Sunday            9500
  4. 10:00AM Sunday   10000
  5. 4:00PM Sunday       9600
  6. 10:00PM Sunday     9200
  7. 4:00AM Monday     8500

Note;  in a storm like this the snow level is usually 500 feet below the freezing level.  (saturated air mass)

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The first in a series of wet storms will hit the sierra beginning today with 36 hours snowfall forecasts in the 4 to 5 foot range for Mammoth Mt and 2 feet plus at the 8000 foot level for Mammoth Lakes. There is a small Atmospheric River taking place tomorrow Wednesday. The Cold Air currently in place will gradually get flushed out over the next 24 to 36 hours. The set up is cold troughing in the pacific NW coupling with a WSW mid latitude upper jet undercutting the GOAK Ridge. This is associated with Gulf of AK Blocking pattern #1. (-EPO); Pattern #2 will be associated with the same ridge that will retrograde (back up) to the Bering Sea. The teleconnection is called the (-WPO) This pattern is warmer and wetter because with the new location of the upper ridge, and energy coming over the top of the ridge will dig a new long wave Trof, both further west and deeper into the Eastern Pacific. It just so happens that there is a mid latitude subtropical low NNE of Hawaii that will be picked up Saturday and Sunday. This coupling of this action picks up the AR and pulls it onto CA Sunday. This AR is a large one and broad. It is a two-day event. It will have precipitation rates of 1 to 2 inches of QPF  every 6 hour period for over 24 hours.  Last nights WPC 7Day QPF  showed 25 inches over the Central Sierra near Mammoth. That does not cover the end of this storm cycle.

 

If you want to know if the end is in sight, you have to know when the block will be gone from the Bering Sea. It looks like it will weaken by the end of next week.  So if that is true, about the 15th or so should  be the end of this pattern. If the blocking persists with any significance, the pattern will continue wet until which time the block either falls apart or it retrogrades west over Siberia, Rus.

Although this WX Patten will be an inconvenience to many, it will be fabulous for the forest and the reservoirs through out the state. It will put a huge dent in our drought!    Watch for Alaskan blocking to most likely return in February as well…..

 

Dr Howard and the Dweebs………………….:-)