Brought to you by Howard Sheckter
Breezy Cooler Weather this weekend with a hint of snow Sunday……More unsettled weather the early part of next week with Light to Moderate amounts of snowfall expected Monday and Tuesday…
Thursday November 4, 2021
Monday night the 8th
Rfc has cut back on QPF to 1.35 inches over Yosemite.
Strong winds are buffeting Mammoth tonight.
Snowfall on mammoth mountain likely lower end of forecast or about a foot.
2 to 6 inches possible in town; will up date in the morning. Note; very unusual the way models are so inconsistent with QPF.
Additional Comments Sure do love the large SSTA pool near the dateline. WPO in negative phase. Good for more AR’S in the future.
Sunday AM PST 9:30AM
Best part of the time change for the Met is that the models come out an hour earlier!!
This mornings model runs have the freezing level going higher. Why? Little in the way of upstream amplification. so storm lacks cold air at our latitude.
I think that if you look at the teleconnections and focus upon the WPO region, you will get a glimpse of the tail that will wagg the dog for the next 2 weeks. This is a high latitude block and although it does not stand out like a sore thumb, it does make you think about the possibilities of what’s connected to it and the results thereafter. Might it be related to the warm SSTAs over the mid high latts between the dateline and Hawaii? Cold air is pouring south, east of that block creating Jet “O” Genesis down stream. The wave length suggests future ARs for the west coast over the next few weeks. So, long fetches of moisture headed for the west coast. However, it remains to be seen if there will be a lifting mechanisms to be beneficial.
MJO: Is expected to progress to the Western Pacific and so prospects for a pretty good sized west coast ridge (+PNA)should result the weekend of the 15th. The ridge is not expected set up inland and so highs will warm to the mid to possible upper 70s by next Saturday in Bishop…..Low 90s possible in Death Valley……mid to upper 60s in Mammoth. 80s LA?
The word for the late Monday night and Tuesday storm is that it will be wet; will have high snow levels. Best Accumulations above 9500 feet. Snow level mostly 7500 to 8500 feet. Expect between 15 and 20 inches above 9500 feet. Main Lodge 1 foot+ Town ?
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8:47am Friday the 5th
Models continue to struggle with AR with it being on again, off again and now on again! Not sure why….Although it will not make a difference on whether we get cooler, windy and have snowfall. It does make a difference on how much it will snow. With out the weak AR, this weather system is probably good for 5 to 10 inches of snowfall. With it, between 1 and 2 feet over the crest. Dweebs will tprecip will occur. another look at it tomorrow.
In the meantime, the new seasonal ECMWF forecast for both precip and temperature is out. Not much change expected for November and December with a slight bias toward above normal snowfall. January came in a bit wetter with the odds tilted toward normal, instead of below normal precip. February is still showing drier than normal precipitation and March is now a bit drier than normal compared to a bit wetter than normal.
The forecast for this weekend is for breezy weather and periods of strong winds over the sierra crest. It will grow cooler with highs returning to the low 50s cooling to the upper 40s Sunday and lows in the 20s. The is a chance of some light snowfall later Saturday night into Sunday AM with an inch or two of snow possible over the upper elevations Sunday AM. The main upper trof and weak AR come in late Monday night into Tuesday. Expect moderate to strong winds with this system, with further cooling expected with highs in the low 40s Tuesday. The storm rolls out Wednesday with a warming trend into the weekend…
Dr Howard and the Dweebs…………………….:-)
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This mornings operational and ensemble model runs continue yesterdays trend of removing the “categorically” weak AR, previously expected for this Tuesday. This will have the effect of cutting snowfall amounts in this case to about 1/2 of what was previously expected. The Dweebs believe that somewhere between 6 and 12 inches of snow is possible from the Monday-Tuesday “weather system” “at this time”. The storm has a good sized long wave trof with several waves, (vort maxes) embedded within it. As discussed in an earlier discussion, The amplification process over the western pacific was never set up quite right in the first place. Not sure why the models were so “Gung Ho” on the AR’s extension through the sierra. As headlined; at this time, based upon RFC’s forecast between Huntington Lake and Yosemite, expect between 6 and 12 inches of snow above 10000 feet, and between 2 and 5 inches in town. The snow level/freezing level bounce up and down on Monday as each wave has a warm air pocket with it. Best accumulations for the Town will be later Monday night into Tuesday AM….
Extended Outlook: The global models show a rather strong long wave ridge that builds into California, the 2nd half of next week, 500MB Heights rise in excess of 588DM over CA. The record high temperature for Bishop CA on the 14th of November was 89 degrees set back in the year of 1906. It was one of the warmest days on record for so late in the year. The Dweebs believe that although that kind of high temperature record rarely occurs so late in the year, it is very possible that Bishop could get into the 80s later next week based upon latest week 2 guidance.
I will have updated ECMWF seasonal outlooks tomorrow.
Here was seasonal outlook from October 1st. for Near Mammoth Lakes
November Slightly above normal
December Slightly above normal
January Much drier than normal
February Much drier than Normal
March Slightly above normal
ECMWF weeklies ensemble show 3 to 4 feet of new snow by Mid December for our part of the Sierra.