Archive for February, 2012

Beautiful Day Friday then Colder and Breezy through the Holiday Weekend…..Snow Showers in the offering…..Expect a Stronger System Next weekend.

Short wave ridging today will offer a very nice day for all outdoor activities. Winds will be light and temps will be warmer over the upper elevations. The next weather system will bring another shot of cooling to the area with some snow-showers and possibly a dusting. None of the models generate any serious QPF. CRFC gives Yosemite about .03 inches. So it will not be a big deal. Cooler and Breezy weather is expected  Saturday into Sunday with highs back down to the mid 30s or similar temps to what we just had yesterday.

The outlook is for fair weather with little temperature change Monday then a gradual warming trend beginning Tuesday into the following Thursday. Thursdays highs will reach the 50s. The following weekend is expected to be stormy and cold!

MJO:

MJO is just leaving Phase Space 1 and is expected to remain in phase space 2 for the next week or two as it slowly progresses East.  Over the next 1 to 2 weeks this should have the effect of the contracting the upper jet over the north pacific leading to retrogression toward the last week of the Month. Although the Air-Sea coupled model has backed off for the time being on a wet beginning of March, the current track of the MJO still suggests a period of more snowfall for the Eastern Sierra between the last week of February through the 1st week of March.

 

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.

Mammoth Mt Picks up 12 inches Past 24 hours….Snowshowers expected throughout the day……Next System This Weekend…..

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.

Mammoth Mt picked up 10 inches Storm Total……Next Wx System Tracking South, a bit further east…amounts in the 3 to 6 inches range expected over upper elevations Wednesday…..Cold showery pattern likely to continue this weekend

Tuesday PM Update:

Updated CRFC QPF showing a drier scenario for Mammoth Wednesday…so 1 to 4 inches is probably going to be it from top to bottom….. An inch or 2 in town as well……

Let hope for a little more westerly trajectory for the Sunday system…..

 

The Dweeber…..

 

 

The Central Sierra will continue with its cold showery pattern through the rest of the week as NW sliders move through California with little moisture. Precipitation is mostly dynamically driven. The next storm for Wednesday is showing up this morning as dryer then the last.  The Dweeb Reports lst discussion indicated that it would be a coastal slider last week. Now subsequent models runs are taking this splitting system pretty much over the top of the Central Sierra with little “over-water” trajectory of a 110knot upper jet. So expect light amounts again aprox (3 to 6 in) possible on Mammoth Mtn mainly Wednesday. Short wave ridging builds in Thursday for some sunshine! But it will continue Breezy over the lip of the sierra, (up-slope wind) especially Thursday morning with good 300mb/700mb coupling. Winds will we much lighter Friday with a milder day as well.

Weekend Outlook:

The weekend looks unsettled as another short wave….this time an inside slider brings wind, cooling and snow showers Saturday afternoon into Washingtons birthday. Again, at this time it appears to be an inside slider according to the EC and GFS…so light amounts of snowfall expected. ( a few inches). Will update Friday

Longer Range:

The Dweebs can not ignore the fact that the long range pattern in the means is showing discontinuous retrogression. This means that over the next three weeks the eastern pacific ridge will be workings its way west…west of Hawaii. This may eventually result in a very stormy pattern for the Eastern Sierra with heavy snowfall the beginning of March.  The Air Sea coupled model has been touting this for a week now with the 500mb positive height anomaly well west near Hawaii and the negative 500 heights anomaly over Ca.

The MJO which has just moved into Phase space 1 from 8 is about as far east as it is going to get, just east of the dateline. According to NCEP, the MJO is expected to remain active the next few weeks as it reemerges into the Indian Ocean in Phase spaces 2/3.

As the MJO gets into the Indian Ocean and progresses east, the PNA index will flip from its current positive phase to one of Negative. During the MJO progression toward the Maritime Continent, the upper Upper Jet across the pacific should contract, leading up to the -(PNA).

Thus the the current storms that are splitting south with small shots of energy coming into California should come in stronger from the west, as the negative phase usually rules between 70E and 100E. Coinsidently, the global models do show retrogression the end of this month, “possibly” leading up to a wet March.

 

PS: Here is the loading pattern for the +(PNA); Just flip it for the negitive phase.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/pna_loading.html

 

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.