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Archive for December, 2018
Another Cold Shot of Energy dropping South through the Great Basin with Snow Showers Monday then Moderating Temperatures into the first week of the New Year…..There are an increasing number of ensemble members of most global models touting the return of an Active Pattern by next weekend…..However, this is a pattern with a lot of splitting going on…..
Sunday December 30, 2018
January 1st, 2019
Days will be milder beginning Wednesday with seasonal temps for Thursday and Friday….There will be a return of the 40s for highs Thursday and Friday. Lows near zero of late, will rise to the 20s….lighter winds aloft will be highlighted.
Upcoming pattern shows promise to bring significant snowfall beginning this weekend. However, there will definitely be a split in the upper flow that will give forecasters problems. There looks to be a storm or two in the bunch at will give the Sierra plentiful snowfall, however, others that seem headed in our direction that will dive down the coast and miss us completely. Looks like a head banger pattern to me….
The Dweeber….
12-31-2018 Update
Happy New Year From the Dweebs!!! Latest gfs and ecmwf global model runs show a number of systems next week, bringing either moderate snowfall to possible heavy snowfall for a time. The Euro (ecmwf) has a small atmospheric river tied to a system on the 7th.
These are just forward looking systems that have little confidence to forecasters at this time. If the trend holds through this Wednesday or Thursday, that would be very encouraging… The guidance suggests 1 to 3 feet of snow next week, just from this mornings 12z runs. That is not a forecast…
12-30-2018 As headlined….Another Cold Slider drops south Sunday night into Monday night bringing with it a short but chilly period to the Eastern Sierra Monday and New Years Day. Thereafter. a milder period will develop with light breezes by Mid-Week with more seasonal temperature’s Wednesday through Friday.
The Dweebs this morning can not ignore the odds of the return of an active pattern for the following weekend. However, the devil as they say, is in the details. This week, the MJO fly’s rapidly through phase 6 into 7 and Phase space 7 shows better odds of being wet in parts of California. It still favors Southern CA the most, but the CFS shows in this instance, wet for most of the state week 2. We will hopefully know more by Mid Week.
FYI, next weekend is the end of week one and the following week being week 2. Week 2 may prove to be a zinger! 😉
Sensible Weather:
Expect highs in the upper 40s today Sunday, followed by mid 20s on Monday with light snow showers Monday. Expect another round of cold NE wind on Mammoth Mt with strong wind chill’s Monday. New Years morning will likely be in the single digits with highs in the low 30s….There is a warm up Wednesday into Thursday. Thursday’s high temperature will warm back into the upper 40s. The pattern expected the following weekend will involve milder pacific air. However, if by chance the initial system comes in over cold air left behind over the Owens Valley with no surface wind, there could be some snow for the Owens Valley floor. The Dweebs hope to know more by Mid Week. PS. The Euro favors the more southerly track while the GFS has more of a track further north. Time will tell…. Of note, transitionary pattern forecasts are less reliable…
Cold Inside Slider pattern will bring snow showers and cold temperatures to the high country…Gusty Winds over the higher elevations prompts the awareness of a Wind Chill-Factor….. Temperatures to moderate over the weekend….No Major Storms in sight….
Thursday December 27, 2018
12/29/2018 10:00AM
Thoughts about the long range….
When ever I see a possible series of storms during any month of Winter in the week 2 period, IE in this case, between January 5th and the 11th, I always look to see where and how strong the MJO is. The MJO has a statistical relationship to the longer range for weeks 1 through 4. In this case the week one period falls within the MJO phase space 5 and 6 and for January, this tend to be a drier than normal period through early in the phase space 6 with heights increasing along the west coast; See: http://www.americanwx.com/raleighwx/MJO/MJO/JanuaryPhase6gt1500mb.gif
So the current Saturday 12Z run has some support for the weekend storm of the 5th of January late Phase 6). However, the ECMWF Shows a weakening MJO as it moves into this western pacific region with an increase in heights in the +PNA. It delays the storm into the week 2 period. Prind point here is that using only the GFS, the weekend storm of the 5th is a somewhat low confidence bet at this point. Going from phase 6 to phase 7 has a better relationship to storminess for CA and that comes during the week 2 period. This time of the year, the week 2 period storm track may favor Southern CA best, especially early during week 2 then further north later in week 2. SEE: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/LaggedComposites/whmjo6.djf.z200composite.web.png
12/28/2018
Mammoth Weather.com picked up 3 inches of snow over night. Skies are clearing….it is cold with highs near 20 today. There is a wind chill factor on Mammoth Mt today….ware face protection….:-)
As Forecasted…A a cold inside slider is bringing snow showers and cold temperatures to our region. Temperatures are running some 20 degrees below normal for this time of the year which should be in the low 40s. Both Thursday and Friday nights lows will likley be below zero over much of Mammoth. As the upper flow becomes more NE/SE orientated today, upslope snow showers are likley with light accumulations expected. 1-3 inches. Friday will be the coldest day with highs near 20 degrees.
The Weekend outlook shows moderating temperatures that become seasonal by Sunday. Wind protected colder valleys along highway 395 are likley to experience over night lows around -10 to -15 or colder.
The longer range….First week of January is being forced by a strengthening MJO entering the Western Pacific. With the MJO in phase 6, it is likely to suppress storms and precipitation over California through the first week of January. SEE MJO Phase 6 composites for California (jan): http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Precipitation/DJF/combined_image.png
This MJO is an area along the equator highlighted by a pulse of rain and thunderstorms. It is currently over the far Maritime Continent moving westward to the western pacific. Strong westerly wind bursts are now occurring over the Eastern Indian Ocean. See: http://www.bom.gov.au/climate/mjo/#tabs=Time-longitude In that the American GFS model and their ensembles really amplify this MJO feature to the point of +4 deviations of normal, it will be very interesting to note things like latent strong westerly wind bursts that develops in response, that possibly intensifies El Nino on a climate scale of time. However, on a shorter time scale, if the Climate Forecast system, (CFS) is correct, noting and contrary that the GFS and ECMWF appears to be much quicker and less amped, it is possible to have a strong atmospheric response on the central west coast in the form of an “AR”, sometime depending upon the speed of the MJO, during the week 3 period of January. The composites relate to warmer than normal temps for California phases 7 and 8 with a bias for precipitation in phase 7 followed by drier than normal in phase 8 then wet again phase 1. The classic MJO induced AR’s usually occur when the strong MJO crosses from Phase 8 to phase 1. The pattern can be forced by Rossby Wave Dispersion into the Pacific Basin with fast Meridional flow aloft, followed by retrogression of the long wave features over the Eastern Pacific. An extension of the East Asian Jet to the west coast is then possible. The process includes undercutting the EP ridge forcing -EPO, that transits to -WPO. it is a wait and see if the ECWMF and GFS follows suite. This of course is always a long shot, however possible…
Sensible Weather: Watch to see if: 1. we have a dry week during first week of January; followed by a possible storm during the second week of January, followed by a strong amplifying ridge in phase 8 with dryer than normal weather, followed by Pineapple express. Timing may change depending upon speed of MJO. Of course, if the current runs of the GFS and ECMWF are correct, then this post is one for the trash can.
Will Watch to see if the ECMWF and GFS falls in step with the NCFS keeping the MJO very strong and propagating it through phase spaces 7, 8 then possibly 1. The fact that the ENSO basin has not fired up convectively yet is a good sign in this respect.
Dr Howard and the Dweebs……….:-)
Forecast Models Coming in a Bit wetter today for the Christmas eve storm…..thereafter…inside slider pattern to wrap up the year with below normal temps and periods of mainly light snowfall….January will begin mostly on a dry note
Sunday December 23, 2018
Warm Frontal precip began in Mammoth around 3:30PM, however UVM related precip will start about 8:30pm tonight..
12:30pm Christmas Eve;
looks like our storm has slowed a bit. It’s beginning looks to start between 8:00pm to 9:00pm tonight. Looking for snowfall accumulations between 12 and 18 inches between Main lodge and the upper bowls by Christmas mid Morning. In town….expect some 5 to 10 inches by 7:00AM. Christmas Day looks snow showery with another 1 to 3 inches. Next weather system will bring snow showers, later Thursday into Friday. That will be followed by some very cold weather. Another COLD slider looks possible New Years Eve.
Long Range: MJO forecasted into Phase 6 and 7. (Western Pacific) GFS went bonkers…The ECMWF is not nearly as strong. The Dweebs feel that strong ridging will take place the first week of January, following by possible retrogression, then sometime beginning the 2nd week of January, an active wet pattern will develop. This is based upon climate models weeks 3 and 4.
From Sunday AM; Latest guidance this morning from the 06z and 12z runs are showing a richer PWAT push of moisture ahead of the Christmas Eve storm. This means that we can expect a bit wetter scenario Monday Night with amounts now projected to be in the 10 to 15 inch range over Mammoth Mt. The Town of Mammoth could see anywhere between 5 to 10 inches by mid morning Christmas Day. The storm should clear out to just snow showers over the higher elevations by mid morning on the 25th. Between Christmas Day and January 1st, we can expect weather systems to take on a more inside slider track. This means that weather systems (WX) will drop south along the eastern slopes of the sierra or Great Basin producing upslope snow showers. There is a significant wave coming through Thursday night and another about New years Eve.
Happy Holidays to all from the Dweebs!!
