Mammoth Weather

10:50am Update.

Light band of snow has moved into Northern Mono County. Snow showers should develop before noon here in Mammoth….Expect about an inch by tonight. 

Locals are saying it the best skiing now of the season! If you’ve thrown in the towel on the 2012 winter…your missing out big time……The Dweebs are expecting that the next 4 to 6 weeks will be fabulous as a deepening snow pack continues to improve on the existing base….  

Skies currently clouding up as surface front approaches….A band of light precip is fizzling to the west of Alpine County while the main band approaches Tahoe. Not sure how much will be left by the time it gets down here today…. Cooling and breezy WX is the main theme today with further cooling tomorrow. 

In the back of this system…an upper high aloft will build in across the west. Gradients will increase resulting in off shore flow pattern developing Monday through mid week. This will bring gusty winds to the Sierra Crest beginning Monday that will increase Monday night into Tuesday. Winds will probably be in the 80mph+ class out of the N then eventually out of the NE. An extended period of these winds will create Santanna conditions for Southen Ca. next week. Winds are likely to continue through Thursday.  (Note) The Town of Mammoth and the lower slopes are effected much less from these winds.

Longer Range:

Confidence at this time is increasing for a change in the pattern the last week of February with “MJO Induced Retrogression” of the pattern over the north pacific. The upper jet contracts westward in response to tropical forcing over the Indian Ocean by the end of February as the PNA sign flips from + to -.  Both EC and GFS Global models maybe picking up on this now as they are showing retrogression in the long wave pattern. Today’s 12z operational GFS as well as last nights 00z 7 day means centered on day 11 show retrogression of the Eastern pacific high westward to Hawaiian islands and beyond. See: http://www.hpc.ncep.noaa.gov/cpc/cpc_NAM_f264wbg.gif 

With the support of the MJO now entering Phase Space 2…..the odds for a series of storms that will be beneficial to the Sierra Snow-pack is looking better, beginning about the end of the month into the first week of March.  At this time the NCEPs 8 to 14 day outlook does not show above normal or even average precip for Ca. This may change in the coming days….. 

Dr Howard and the Dweebs………………………..:-) 

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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.

Nice little storm with a 4+ inch per hour burst at the main lodge between 6:00am and 7:00am. So we did a little better then expected….

The upper level system will head due south today…away from Mammoth, with a chilly air mass in its wake. Gusty winds will continue throughout the day. Expect highs in the mid 20s at the Village and teens up on Mammoth Mtn today.

The next weather system to effect our area will be Saturday through Monday. The current runs do not form a close upper low at this time with it. So, in will probably be a faster mover, less dynamic and bring less amounts of snowfall.  Best guess at this time 2 to 4 inches….Saturday through Monday AM

It’s always nice to get snowfall when the PNA index is positive. I guess its a blessing with the mean ridge position is just far enough west for systems to drop over our heads,  for some light to moderate snowfall.  The snowfall that fell is the light powdery kind with ratio’s about 15:1

Well its the Middle of February, the Air-Sea coupled models are still touting a wet beginning to March, what say the MJO?

Of note…

All three of these MJO Phase Spaces that extrapolates the MJO beyond the data point are showing either a bounce into Phase Space 2 or a moderate to strong incursion as it travels eastward through phases 1…2…3…and possibly 4. Again like was explained last week….. The MJO moving into Phase Space 2 causes the upper jet across the pacific to contract (retrogression) which results in a FLIP in the PNA index to Negitive. IE. Trofing over the Eastern Pacific and storminess south down the west coast. The PNA teleconnection is currently in the positive phase.  For further discussion please check previous discussions….over the past 7 to 10 days.

Here are the 3 phase spaces that the Dweebs watch:

NCPE: (From The NCEP Ensemble) (American)

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_phase_21m_small.gif

EMON: (From The EC Ensemble) (European)

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/EMON_phase_51m_small.gif

JMAN Ensemble:  Japan Met Agency

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/JMAN_phase_51m_full.gif

Of Note:

The latest 12z GFS is showing retrogression of the HT 500mb height anomaly during week 2.  So the flip may occur during the last week of February with serious storminess returning to the high country the last week of this month.

Comment: The Air-Sea coupled model has predicted this for first week of March.

So today’s 12Z, 2-15-12 GFS run may be too fast?

Dr Howard and the Dweebs…………………………………..:-)

————————————————-
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.