Brought to you by Howard Sheckter
Chilly Northwest Sliders has put snowmaking on Mammoth Mtn into high gear….Althrough it is another Dry 5 to 7 days ahead…a few NW sliders will keep it chilly……Who’s afraid of the Modoki El Nino!
Thursday November 8, 2018
Monday Night 11:10pm
Both 12z GFS and ECMWF have run. EC ensembles have not run yet.
It will be very interesting to see which model does the best next week. Huge difference between the two at this time. I still favor the ECMWF as it has been more consistent. It is the wetter scenario. New deterministic says 1 to 2 feet by Friday over the crest. Again this is a long way out and the GFS is pretty dry for us that same period…
Monday Afternoon November 12th
Just to add some confidence to my forecast for next week, the new 8 to 10 Day outlook just out, goes wet for the Southern Half of California with the bullseye for Southern CA. The Central part of the state has precipitation during the period, but dynamically, the emphasis is LA and San Diego. The upper jet favors Southern CA with a Southern Stream jet. Just to add misery for the fire victims of the south, this southern stream may be the theme of the winter, once EL Nino kicks in. So areas below burnt foothills and canyons should definitely start thinking about sand bags for future storms this winter….
Monday AM;
Just to reaffirm;
Although there my be mixed signals from various forecasters for storms during the week of Thanksgiving, the Dweebs are still viewing this time frame of transition out of the dry pattern of the Fall to one of wet. In the post below, it was stated that the storms would be in the light to moderate range, however, we can not rule out that something more major is brewing as well. The two global models that most meteorologists use as forecasting tools show a system about Tuesday for Southern CA and again later that week. The GFS is not as strong with the second system between Thanksgiving and that following weekend as compared to the European. The point here is that looking at the deterministic version of the European, it is showing some 2 to 4 feet of snow by that end of that week while its ensembles are showing some 12 to 18 inches. I prefer the Euro over the GFS in this distance of time. As stated below, we will have better visibility later this week. The idea of a small storm seems to be getting less attention in my estimation by the end of Thanksgiving week. We have a long way to go time wise and the models will be adjusting a lot with each run so the way to play it is, that it look good for a storm or two but the details still have to be worked out as far as how much and when.
Of note;
Once we get into this pattern change, the climate models (the CFS) keeps it wet through the 9th of December.
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Sunday 10:35AM
We’re still a go for snow during the week of thanksgiving. Nothing large…..Light to possibly moderate snowfall for the week. Visibility increasing this week for the next week in both the ECMWF and GFS..
Dr Howard and the Dweebs…………….:-)
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Saturday 10th; 1:30PM
Long Range continues to evolve with global models picking up on the change. Both ECMWF and GFS and GEM Ensembles are the strongest with the trough the end of the week following Thanksgiving. The models will change throughout the next 10 days on this pattern. You never know it may be pushed back, but so far so good!
The Dweeber…………………..:-)
Friday AM:
Still nothing convincing yet in the ensembles from last night, however, the Climate Forecast System shows it wet during weeks 3 and 4.
Click on the link below then click on weeks 3 and 4 precipitation.
http://www.cpc.ncep.noaa.gov/products/people/mchen/CFSv2FCST/weekly/
New 12Z Global model runs show bulk of cold air pushed off the coast of upper New England by the 15th. Global models should have good consensus of the Thanksgiving week by then.
The Dweebs are still holding on to the period Sunday 18th through Sunday the 25th as being potentially stormy.
Climate Outlook for winter 2018-2019 PDF (Pioneer Model) Last year and this year
https://bluehill.org/Winter_2018-19_jd.pdf
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Thursday Night the 8th…11:15pm
Global Forecast Model beginning to trend with the Dweeber’s idea for a storm about the week of Thanksgiving. Both deterministic runs of the GFS and GEM show a nice little Trough the weekend before Thanksgiving. The Deterministic EC does not agree. Will check in the morning and see what the Ensembles of all these forecast models show….Remember, once the bulk of the cold air gets close to moving off the east coast, there should be an adjustment in the models….Stay tuned….update in the Morning…..
……………………….:-)
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Latest NW slider has dew point now down to the Single digits. With high temperatures in the 30s and low 40s on Mammoth Mt, That is going to be very good for almost round the clock snow making. Although daytime temps will rise a little over the next few days, another NW slider will bring more shill Saturday night into Sunday.
Lots of talk about the Modoki El Nino this year. As with most weather signals, as they relate to our winters wet season, the Modoki El Nino is not 100% for a dryer than normal winter. Most of you know the big winter years of the past like the winter of 1978 and 1969. Here is a list of Modoki El Nino years and you will see that we have had some big-big winters with the El Nino Modoki…..Also some pretty dry ones too,
These are the basic Modoki Winter years and precip associated with it from various sources.;
LA Rainfall SFO Rainfall Mammoth Mt Snowfall inches Winter of
21.13 10.46 Unknown 1957 1958
7.93 22.29 Unknown 1963 1964
20.44 29.41 Unknown 1965 1966
27.47 20.80 Unknown 1968 1969
7.66 17.44 196 1986 1987
21.00 26.66 226 1991 1992
22.29 24.35 540 1994 1995
20.80 16.49 356 2002 2003
17.44 37.25 570 2004 2005
As you can see, Los Angeles has had above normal rainfall, 7 out of the last 9 Modoki winters. (AVE- RF) 14.93
San Francisco has had “about” 6 out of the last 9 Modoki winters with average to above average rainfall. (AVE 23.64 inches)
Now for the good news!
The Pioneer Model which does a very good job in forecasting 500MB Heights, shows this for this winters analogs winter years in its winter forecast.
Here are the new analog data set recently released: This means in simple terms, the winters that most resemble pattern wise what this models forecast is;
1963/64, 1965/66, 2009/10, 1996/97, 2013/14, 2004/05, 1968/69, 2003/04, 1977/78, 1966/67. 2003/04 and 2013/14.
Winter of;
1964 dry
1966 Wet
2010 Wet
1997 Wet
2014 Dry
2005 Wet
1969 Wet
2004 AVE
1978 Wet
1967 Unknown for Mammoth….Wet in LA and Dry in SFO
2004 Average
2014 Dry
*Dry means more than 85% to 90% below normal; This is my criteria in this report, not the standard
Wet is 110% of normal or greater; This is my criteria in this report, not the standard
Odds are, based upon the Pioneer, Model, we stand a better than a 60% chance of an average to above average winter even counting the Unknown as dry.
There is no question in the Pioneers model forecast that the western hemi 500MB config is an El Nino with a strong southern stream developing sometime during December and hitting California top to bottom in January. Otherwise it favors Southern CA December and February up through the Southern Sierra for greater than normal precip. Again this is a model forecast, however, not set in stone.