“Series of storms to ride upper jet into California through much of next week”
Tuesday March 15, 2011
Posted at 10:25 am by Howard
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.
Dr Howard and the Dweebs…………………………………….:-)
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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.