Archive for March, 2012

Tempo To Pick Up Later This Week As Series of Systems Affect the West Coast……Additional Snowfall is likely Next Week as Well…..

Wednesday AM Update

Mammoth Mtn picked up 2 inches at the main lodge and up to 4 inches over the upper elevations….

.44 inches at the main lodge plot past 24 hours.  .10 at MammothWeather.com with a dusting over night…..

Another 4 inches is possible later Today/Ngt in the “Upper Elevations”….

CRFC QPF paints 1.39 in the Yosemite Valley for 24 hours amounts Friday/Ngt so considering temps, 12 to 18 inches additional expected by Early Sat AM on Mammoth Mtn with Much Much more during the rest of Saturday AM.

No local plow expected now until late Friday or Friday night as the snow levels remains above the village….

Tempo to pick up late Friday Night as the dynamic portion of the upper jet makes it way south into Mono County. The snow-level will fall later Friday night then rapidly into Saturday.  A period of Heavy snow is expected early Saturday morning until the front comes through. (FROPA) is currently expected between 10:00am & 11:00am….then showery weather Saturday PM for the remainder of the day will “additional significant” accumulations. Showery weather will continue for the following day or two with lighter amounts…..Highs by Sunday in the mid 20s……

Would expect a winter storm watch hoisted for Late Friday Night and Saturday…….By Thursday Afternoon from NWS.

The Longer Range is changing……Stay Tuned to Mammothweather.com…….Mammoth’s best local weather source……….

 

Dr Howard and the Dweebs…………………….:-)

 

 

From Tuesday AM:

As earlier indicated….Tahoe north will get the Lions share of the QPF from the series…However, Mammoth well get a nice dump from the 3rd storm over the weekend….now located between the dateline and Hawaii.

The winds picked up last night with the main action focused this morning well to the north of Mono County as expected…

This 1st system is quite windy and is expected to lift-out NW of our area late today with the 2nd expected Wednesday into Thursday. The first few systems will not spill over much to the east other then to allow some 4 to 6 inches over the crest between Wednesday through Thursday. The 3rd storm is the charm with the coldest temps, best dynamics, upper jet support and best follow through over the Sierra on to the east. This is the one that will be plowable for the residential areas of Mammoth beginning Friday then through the weekend.

The 00z Tuesday GFS had a 500-1000mb thickness pool just west of Mammoth of 522DM early Sunday morning.  Good for a snow level of about 2000 ft. Thickness’s will go from 540dm Saturday at 5:00am to about 530dm by Sat 5:00pm. So the snow will be light and powdery by Saturday afternoon then becoming even drier by late in the day into the night. Storm Total QPF is always dependent upon how fast the system blows through. As of this time….it is forecasted to be about 3.50 to 4.00 inches by weeks end near Yosemite…..good for 3 to 4 feet over the higher elevations by Sunday PM. Sunday looks cold and showery, then additional short wave energy is expected the following week.

LA’s best shot will be Saturday with best dynamics between early Saturday AM through the mid afternoon……with several areas getting well over an inch to possibly two of rain in some pretty good down pours.

 

Longer range:

The 12z GFS has improving conditions Monday through Wednesday next week as the next trof becomes closed off and waits for the boot from the next upstream system the second half of next week.  Although that is certainly possible, the ECMWF is just slower moving the big upper trof out with then the next upstream system working its way into the west coast Thursday/Friday.

 

PS…..What’s a Snorkel Train?

Something Gary or Arnie made up from KIBS….

 

 

The Dweeber……………………..:-)

 

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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Increasingly Wet Week for the Eastern Sierra…..”Snorkel Alert” for Mammoth Mt Next Weekend!!

Monday AM Update:

Mammoth’s best action for snowfall will occur, beginning Friday through next weekend…..

 

I guess it is only fitting that winter will arrive just in time for Spring this year.  Will it be Fall next Summer??? 🙂

Here is the latest info….

The Dweebs have looked at all medium and long range guidance including the most recent 12z operational ECMWF which has at 500mb…a 240DM drop in heights Just South of Monterrey Bay between 12z Friday and 12z Sat. Then another 120DM drop over the following 24 hours……  That’s some serious height falls!! Thicknesses in the cold pool have to be in the 518s Can’t wait to see HP 500 temps in the upper low!!  Snorkels anyone? or at least keep your CPAP high and working, if you plan on snow camping Saturday!

Now until we get to the weekend, we have some pretty wet unsettled weather to get through.  A series of impulses will move through the pacific northwest and Northern California. The upper flow will become WSW natural to the sierra and so excellent orographics will be in play even though the upper jet dynamics remain well to our north. 700mb RH will vary between 50% and 90%. Monday through Wednesday. Tuesday and Wednesday seem the wettest for the first half of the week. CRFC puts a little over a half inch of QPF in Yosemite Valley between Tuesday AM and Wednesday AM. The same forecast time frame has the freezing Level at 7800 feet over Mammoth.  Not too sure what to think about that though. (Seems low?) if not then several inches could fall at the Village Wednesday AM.

This mornings 12z GEM model actually has some UVM Wednesday morning for Mono County as a Vort center swings through…. Although the Town of Mammoth may not get into any serious snow until Friday…the upper mountain with good orographics and lots of HR at 700mb may get a foot+ Tuesday into Wednesday with the winds natural to the Sierra.

Then the excitement begins….Friday as the upper long wave reloads with two powerhouse short waves that move into Central Ca then south to the Mexican boarder to give LA a wallop as well.  The Weekend storm could drop 3 to 4 feet of Light fluffy powder……IE “Platinum Powder”

 

More Later………………………….

 

The Dweeber……………………….:-)

 

 

————————————————-
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.

Fair Weather For the Next Two Days Then Eastern Pacific Troughing Setting Up With Snowfall Possibilities Next Week….

Brief Update Saturday:

Trend is intact for an Eastern Pacific long wave Trof to set up over the next few days. Although the upper jet still favors the pacific NW and Northern Ca through Mid week….The systems become increasingly wetter by mid week. As we get to Friday, Strong upstream amplification occurs on both EC and GFS models. Thus confidence remains high for a significant storm that will bring several feet to the high country of Mono County beginning next Friday through St Patty’s Day weekend. The storm is cold and the Powder by the end of the week could potentially be the deepest and best of the year. (Don’t put your boards away yet!) 

FROM FRIDAY:

This mornings satellite showing the upper ridge right over the golden state and 12z gfs forecast run showing best warming aloft today with the calmest winds over the Northern half of Ca. The southern half of the state has off shore flow with warming as well. Expect highs today in Mammoth to push over the 60 degree mark for the first time this year….

Temps in the Owens Valley will move into the 70s with little change in temps Saturday for the Owens Valley. Mono County will be a little cooler, with an increase in breeze and high clouds by the afternoon. The upper ridge will begin to both weaken and shift east.

Next week the well advertised long wave trof is still expected to set up over the Eastern Pacific as increasing jet energy and eventually amplification upstream drives the upper jet toward the southern part of the state the 2nd half of the week.  As a note, the MJO did have the effect of retrogression over the north pacific this past week. However the pattern over the pacific has not been amplified enough to get the upper jet south down the west coast.  That may have something to do with the +AO? Maybe, maybe not.  All I know is that mother nature has been pretty stingy this year with high latitude blocking in the areas that are most conducive to central west coast storminess. The Equatorial-ward trajectories of Arctic Air over the Western Hemisphere have been both anemic and infrequent.  As of note, according to the latest snap shot, the AO will be trending toward neutral next week and possibly even briefly negative by St patty’s day.

The Dweebs have taken a look at the 00z GFS 3, 5, 8 and 11 day means as well as the amplitude of the wave pattern across the north pacific next week.

What is note worthy is that for the first part of next week the front left exit region of the upper jet with the best forcing favors the Pacific Northwest beginning Sunday with the Rt rear entry region favoring Northern Ca. So once again, the Northern Sierra will get the best of the precip the first half of next week. I will note that the mid week short wave is definitely wetter with a lot of pacific moisture being entrained into the system. Some of that will bring us snow fall here in Mono County, Tuesday into Wednesday. However, it does not appear to be big amounts. Beyond mid week, the most significant system for the Mammoth area appears to be associated with the most amplification of the long wave in addition to progression of the same, as we go from Friday the 16th through Monday the 19th. That appears at this time, to be the best “IOP” for the Central Sierra next week!

More updates on the way later this weekend……..>>>

 

Dr Howard and the Dweebs……………………….:-)

 

MJO…the Hows and Whys: (Subseasonal Synoptic Model)

The framework for the model is global atmospheric angular momentum (AAM), which varies with the amount and distribution of westerly flow and mass in the atmosphere. The MJO produces a robust signal in global AAM because as equatorial convection anomalies propagate eastward the accompanying surface wind and pressure anomalies induce anomalous mountain and frictional torques. The torques exchange angular momentum between the atmosphere and the solid earth. The MJO mountain torque comes primarily from subtropical topography and depends on the MJO’s surface pressure anomalies and their placement relative to the African Highlands, the Himalayas and the South America Andes. Momentum and heat transports by atmospheric eddies organize the angular momentum produced by the torques and give rise to a zonal mean wind signal that propagates coherently poleward from equatorial regions into the subtropics. Such anomalies are strong enough to influence storm track variability and wave energy dispersion in mid-latitudes.

 

 

 

————————————————-
Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.