10:00AM  11/7/2022 Update

Although Mammoth Mt reports 4 inches at the main lodge this AM, temperatures have been well below freezing on the top of Mammoth Mt, during the weak AR, Sunday. The weather plot at Sesame tallied over an inch of water in the data. Thus it is likely that the upper mountain above 10000 has picked up a foot of snowfall, so far this early morning. That is part of the 4 to 5 feet expected.

The Upper Low continues to dig south along the west coast.  The Central Sierra will be under Cyclonic SW flow with good orographic’s today and Tuesday. At the moment, the upper jet of 150 knots at 250MB is due west of the lows centered, near Southern Victoria Island, Canada, so digging continues.

Tonight, the nose of the upper jet will begin to round the base of the digging trough and move on shore about Santa Barbara about 4:00AM Tuesday. Shortly after, by about 7:00AM, very strong upper divergence will occur over Mammoth Lakes and the Southern Sierra.  With the upper jets front left quad taking over, snowfall rates rapidly increase to between 2 to 3 inches per hour in our area, with heavy snowfall expected much of the day into the night. Thereafter, the upper jet pulls the upper trough east then lifts it NE with its axis expected to come through about 10:00AM Wednesday. That is from this mornings 12Z GFS deterministic run. Thus improving weather is expected during the afternoon, with snow showers tapering off. It should clear over night with Blue Bird conditions very possible Thursday. However, for the first part of the day, gusty winds over the crest could be expected, diminishing during the day.

The Outlook for the weekend is less certain. Pattern goes into transition.  Although a strong -EPO is developing with an enhanced southern stream. The MJO is weakening rapidly now and thus the strength of the incipient southern stream is expected to die out leading to a large cut off low trapped below the closed upper high over AK.  There maybe something weak that gets in here early next week, that may bring some showers or light snowfall; but the trend now is for rising heights over the far Eastern Pacific. The new pattern will eventually deliver a series of chilly short waves from Central Canada to upper mid west,  and eventually the Great Lakes week 2. A Hudson Bay Low will try to establish itself toward Thanksgiving. Meanwhile, watching the MJO and Rimm Phase Space, there is some suggestion that the MJO or other air-sea coupled Kelvin or EQ Rossby wave will enhance tropical forcing in phase 6 (western pacific), possibly progressing to Phase 7. So we may be off to the races again…. As  always…Stay Tuned….:-)

 

The Dweeber………………..:-)

 

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Powerhouse Storm from the Gulf of AK is digging its way south tonight. Expect the snow level dropping below the Town of Mammoth after Midnight tonight. Storm is running slightly slower. Snowfall Rates will pick up Monday as the freezing level drops below 7000 during the day. The precip plot up at the main lodge shows a storm total of about an .75 of rain so far. So 6 or 7 inches of snow so far on top this evening? Its interesting to note that the Bullseye of the precip is in the Southern Sierra this time, but not that far south of Mammoth.

Snowfall rates will increase Monday with snow accumulating in town.  Most intense period will be Tuesday AM into the night. Still expect some 4 to 5 feet over the top by Wednesday Eve.

Outlook:

Interesting pattern taking shape with -EPO. This acts both as a high latitude block over AK while forcing subsequent short waves on on more southerly track. Wonder how long that will last? There are several mid latitude systems that may affect Mammoth later next week and beyond….. None exceptional, but potential for moderate storms.

Winter Storm Warning goes into effect at the Witching Hour….

 

Dr Howard and the Dweebs………………..:-)