Building Upper Ridge Over The Eastern Pacific Spells Cooler Weather This Weeks Second Half….More Snow On The Way!

Building HT 500 Hts over the Eastern Pacific the next few days will change the upper flow from more out of the NNW while a long wave trof is carved out over the Great Basin in the 5 Day Means. There will be at least one and possibly two significant systems that will effect the Mammoth area through weeks end. The most significant system is associated with a 130knot upper jet that becomes more NNW-SSE orientated as the the upstream ridge builds between 160w and 140w. Mammoth becomes in the front left exit region during the day Wednesday. Additionally, there appears to be two jets with this system. One associated with a dampening short wave in the anticyclonic flow in the mid latitudes Tuesday,  and the other stronger system associated with the upstream amplification that actually over runs the mid latitude upper jet. The primary jet seems to prime the atmosphere,  prior to the stronger short waves arrival on Wednesday.  Mammoth could get 2+ feet of powder over the crest between Tuesday night and Wednesday night. Additionally, cold modified Arctic air gets pulled down from north of 60N Thursday for a day of teens in Mammoth Lakes. With night time lows in the single digits and minus zeros Friday am. 


New Years Eve System:

In addition to the above……There has been several GFS ensemble members indicating a short wave coming through the upper ridge for New Years Eve. I did not see it on last night EC, but the GFS has several members with it.  So for the time being….there is a chance of Snow around News years as well.

First Week of 1011:

Best guess?

Unsettled…..snow showers. The GFS has the Eastern Pacific High still amped around 140W to 145W and shots of energy could continue into the Great Basin (inside sliders) so it will remain colder then normal for January. However, the ECMWF 12z Sunday runs shows a split flow pattern with a pretty strong southern stream for the southern half of Ca. We’ll see how she develops!

Phase Space:

The “Wheeler Headon” phase space; See:  http://cawcr.gov.au/staff/mwheeler/maproom/RMM/phase.Last40days.html

suggests an increase of tropical convection over the Maritime Continent. However its too soon to say if it will be an MJO. Will check on CPC chatter next week.

If indeed we do have a MJO….watch and see if  another block or REX block develops between Hawaii and the Dateline toward the middle of January.


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.

Splitting System To Bring Quick Shot Of Snow Tonight….Then Showers In The Morning….

Just a quick update:


Winter Weather advisories from 4:00pm tonight to 4:00am Sunday.

No changes to forecast. Splitting system will weaken frontal band as it approaches the Sierra. Southerly flow aloft not conducive to orographics and will not favor heavy precipitation.


Forecast remains…..  3 to 5 inches in town tonight from a quick band of moderate snow….with snow showers in the morning.  Upper elevations 5 to 8 inches….9,000feet+

Strong gusty winds over the upper elevation today

Highs in town in the 40s… lows tonight in the teens and 20s…

Some non-politically correct reading as we go into the New Year!

http://www.landscheidt.info/?q=node/205


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.

Christmas Day Eve Storm to bring a good chance of “Light Snow” for the Town Saturday Night-Sunday AM

Over the past several model runs…there has been a decisive trend to split the next upper trof as it comes into Central California. Negative tilt trofs sometimes have a tendency to do this in the southern portion as the northern portion of the storm with the jet on the front side of the trof is moving along with the system while in this case…lifting NE; while the upper jet on the back side is still digging southeast! The split is over Central Ca and will directly effect the snowfall amounts over Mammoth Lakes.

It is for this reason that the Dweebs now feel that this will be a light precipitation event as the front sheers into the Mammoth portion of the Eastern Sierra. 

Best guess….

3 to 5 inches in town and 4 to 8 innches up on Mammoth Mountain by Sunday Mid-Morning.

500mb-1000mb thickness falls of 100 dm should bring some 8 to 10 degrees of cooling by Sunday. 

Winds:

Winds were pretty light this morning at the main lodge. Even over the crest they were only 30mph gusting to 35.

The winds will increase and strengthen throughout the day with gusts to 60mph by the the afternoon over the crest. It will be even windier by Christmas AM…but should begin to subside a bit later in the day.

Snow will begin falling by late afternoon and then snow is likely Saturday night/Sunday am. Snow level is expected to be at 6500 feet.

Fair weather will return for Monday and Tuesday.


There appears to be a stronger storm out there for the 29th/30th that will be windier, colder and bring moderate amounts.  (About a foot+)



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.