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Archive for year 2017
Small AR expected to impact the Central Sierra Wednesday night pushing south of Mammoth By late afternoon Thursday….Precipitation will begin as early as Wednesday afternoon……Expect a drying trend by Friday Morning then dry through Saturday….
Sunday November 12, 2017
Tuesday AM:
AR has become a moderate to strong AR now with the entrainment of extra moisture from a tropical system…..I will update after 8:30AM this morning the 14th….
………………….:-)
Monday Pm…Love posting when stuff is happening!
OK…Interesting twist this afternoon! The new 12z EURO is splitting the trof coming in this Sunday. This is the one that the GFS has going north into Northern CA and the pacific NW with another AR. But actually there is a fresh twist! If the EURO is correct, it is going to cause a pretty significant change to our pattern, both upstream and down stream as it kicks the trof over the Eastern US out off the coast. That would not make snow lovers on the east coast happy!
More importantly, that change if correct and that a big if, will tend to keep our pattern some what progressive and that means more storms hitting the west coast while the GFS wants to cut it all off. The current solution will help LA get some rain as well as the next upstream system actually splits with a lot of energy going south this Sunday into Monday.
I have to say that the ensembles are against the Euro solution, but why the change? Stay tuned….this is what it’s all about!
PS> The snow level this Thursday is going to be critical to the Town of Mammoth, as there is going to be a lot of precipitation falling. The big question is going to be about how soon the cold air is going to get here. If it comes in earlier than expected, the town could get over a foot. It is too early to know at this time. I will update on the potential change that the Euro is showing in the morning, or sooner if the GFS starts to follow later tonight….
Dr Howard and the Dweebs……………………………….:-)
Monday AM Update:
CRFC is showing about 3.75 inches of water over the west side of the sierra west of Mammoth Mt, Wednesday through Thursday night. With the snow level rising Wednesday from 8000 feet to 9000 feet, little impact from snowfall is expected in the Town of Mammoth Lakes during the day Wednesday. As the AR shifts south Wednesday night, heavy snowfall is expected above 9000 feet over Mammoth Mt with generally heavy wet snow expected to begin accumulating later Wednesday night/Thursday AM above 8000 feet. The Freezing levels is expected to fall Thursday morning and all day Thursday. Rain-snow mix will become mostly snow during the afternoon Thursday for the Town of Mammoth. I expect over a foot of wet snow at the Village at Mammoth, by Thursday Noon and 4 to 8 inches in town later Thursday afternoon.
At the moment, 18 to 36 inches of snow seems reasonable for Mammoth Mt Between Wednesday and Thursday night. Precipitation rates will be especially high Wednesday night through Thursday AM.
I will fine tune all this in the morning Tuesday and again Wednesday….
The Dweeber…………………….:-)
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Forecast models continue to vary on the strength of the 1st wet system of season. The main issues are with the two jet streams, both Polar and Subtropical jets and associated dynamics. The Moisture is a given, but moisture without dynamic lift in an area can play havoc with precip amounts. I think that we are close enough in time to have a fairly good idea that this will be a wet storm for Thursday from early morning to evening as the meat of the AR according to the 00z Monday European model is between 4:00am Thursday and 4:00PM Thursday. There will be good orographics, so precipitation is a given.
The freezing level will be high at about 10,000 feet, however, with subtropical systems, micro-physical processes can mess with snow levels to a big degree, especially during the wettest part of the storm Thursday. However, without much antecedent cold, it is difficult to believe that there will be significant snowfall accumulation below at least 8000 feet Thursday morning.
As cooler air begins to arrive during the afternoon Thursday, the snow level will come down and light accumulations will develop in the lower elevations down to about 7000 by evening. Snow showers are possible Thursday night. Light accumulations are expected in town, as at the moment, the timing says that most of the precip will be over by late afternoon Thursday. Will update again tomorrow.
Potentially, this will be a good base building storm with wet snow from bottom to top on Mammoth Mt.. Amounts could range from “between” 1 to 3 feet. According to the ECMWF, the AR is forecasted to push south of Mammoth by 4:00PM Thursday. The extended looks dry…..
Dr Howard and the Dweebs…………………….:-)