“Series of storms to ride upper jet into California through much of next week”

The well awaited return of the upper jet into Central then Southern Ca will begin Wednesday into Friday. The first of a series of surface systems deepening east of Japan is already occuring and over time will amplify the central pacific upper ridge which allows a series of systems to deepen the long wave trof to a position off the central and southern west coast. Both the 00z Tuesday’s operational  ECMWF and it’s ensembles show and active pattern through much of next week for this area. Even Southern Ca will get beneficial rains next week as the upper jet eventually favors that area.

In the meantime the upper jet still favors Northern Ca today. Considering that were on the anticyclonic side of the jet, plus the usual climatology of March, there will be quite the strong gradient this afternoon and especially tonight as the upper jet begins to slide toward our area. (It will be windy this afternoon and night!)   The jet core will be over us, early Friday morning…then over Southern Ca Friday night. However, the front left exit region apparently does not effect LA until Sunday. That will be the best time for heavier rain in LA if this mornings 12z GFS is correct.

For Mammoth, a moist up-slope flow begins to increase tonight with snow levels above 8000 feet. It will be mainly rain and wind through late tonight. However, the 12z WRF sags the -2.5C iso-hyet at 700mb just north of Mammoth by 11:00pm tonight, so rain should start turning to snow near the village by that time. By Wednesday afternoon the snow level should be about 6500 feet. 

The WX front should be near June Lake at 12z Wednesday and south of Mammoth by 7:00am approached during the early mornings hours…. snow levels will continue falling to about 6500 feet during the day Wednesday. 

I think 2 to 4 inches is possible in town by the afternoon with a bit more above 8000 feet in town. Upper elevations above 10,000 feet may get up to a foot+ of mainly heavy snow.

Thursday’s upper flow is pretty diffluent with short wave ridging. This should make for a decent day before the next storm heads our way Friday. That storm is colder and should bring some 10 to possibly 20 inches with the main punch late in the day Friday into that night. 

The storm door remains open there after with the next system favoring Southern Ca. The New GFS has it rapidly moving into LA mid morning Sunday, then through the afternoon and night. 

Next update Thursday……or sooner of needed. 


Wax-Um Up!!


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.

Couple of inches of new snow fell over Mammoth Mtn Last night with a inch or so in town…..upper jet still to the north of us and is where the most activity is…..amplifacation over the central pacific to push upper jet into Central Ca by Wednesday with larger storm possible for weekend

A cold front has stalled over the Central Sierra north of Mammoth this Am. Some light precip is occurring along the crest and near the front according RAMSIS. The showery weather will dissipate through out the day and precip will then just be focused along the highest terrain in the moist onshore flow. 700mb winds are between 15 and 30 knots and so upper crest winds will be between 30mph and 60 mph today.

The strong west to east upper jet of about 170 knotts along 40 north moves onshore Tuesday morning once again favoring Northern Ca and will bring mainly some light orographically induced precip to the Mammoth Sierra

The system is currently moving through north of the big island of Hawaii  taking the same track that the one that moved through Northern Ca yesterday. It is a little more moist and should be a better precip producer for north Central Ca northward. .

By Wednesday, the upper jet weakens and drops toward the Central Sierra bringing windier weather for Mammoth and a chance of Snowfall with lower snow levels and cooler temperatures. At the moment 1st guess would be 4 to 6 over Mammoth Mt. by Late Tuesday night. The system is warmer then yesterdays and so it might be rain/snow mix in town for a while before turning to snow Tuesday night. Update Tomorrow.

A larger storm is still expected for the Central and Southern Sierra after Thursday. This will be a colder storm.


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.

Little Change in the pattern through Tuesday….Then long awaited southward shift in the upper jet begins about mid-week…..

Not much to add to last Tuesday’s discussion other then to remove any chances of showers today Saturday. The Sunday/Monday short wave has a bit stronger upper jet, and has a bit more moisture. However, is still targeting Northern Ca the most with the possibility of some snow showers or light snow over the upper elevations. The Dweebs would not expect much more then 1 to 3 inches over Mammoth Mt beginning sometime Sunday pm through Monday AM. If, and that is a big if that system drops about 50 to 100 miles further south…that would make a significant difference in the amount of precip.  Snow levels will be pretty high….7500 to 8000 feet

Significant changes well advertised earlier in the past week (see previous discussion from March 8th) begin to occur as upper ridging develops near the dateline causing the long wave trof to deepen along the west coast about midweek. The 12z GFS has the first system effecting the Mammoth area as early as Wednesday. However, that may be a bit fast. Will update on the timing as soon as the models come into better agreement.

The screaming message here is that winter will be making a return….just in time for Spring!



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.