Increasing Amplitude in the Eastern Pacific High north of Kauai and south of the Aleutians…..First in a series of storms to hit Eastern Sierra Friday night and Saturday…..with additional storms possible into New Year….
Tuesday December 20, 2016
Posted at 6:50 am by Howard
Small Adjustment in the QPF this Am with adjustments in the timing as well.
Expect snow to begin falling between 7:00AM and 8:00AM with a heavier snowfall rates after 10:00AM Friday. A winter storm Watch goes into effect at 10:00AM Friday. Heavy snow is expected with rapidly falling temps Friday afternoon into Friday Night.
Expect about (1) foot+ of snow in the Town of Mammoth, with upwards to two feet on Mammoth Mountain by Saturday afternoon. The snow level will begin at 7500 Friday AM, and will fall rapidly during the afternoon to the Mono County valley floor.
Christmas Day will be partly cloudy, dry and cold with highs in the upper 20s.
Full discussion Tomorrow AM in Weather Letter….
Dr Howard and the Dweebs…………………..:-)
The Dweebs wait is over as you can not continue to disagree with recent model trends the past few days, especially when you are closing in to that magic 72 hour window from the event. Although the western hemispheric progressive pattern continues without any real high latitude blocking and both AO and NAO is positive, the eastern pacific ridge is situated in the perfect spot for a wave train of short waves, (Storms) to dig into CA with each showing quite a significant upper jet on back side to get the “Dig Done”.
As an added comment, I have to say that this is a winter in the making that we in California have been waiting for a long time. It has the potential to put a big dent in our drought here in Central CA. Personally, I have reason to believe that there is a correlation between the coming solar minimum and a wetter west. The Sun is in hibernation mode now with little Sunspot action and some scientists are of the belief that the next 5 years are going to be very interesting weather wise…..Wetter in California!
Upcoming storm series: ( These are all cold storms)
- The Friday night system to begin during Friday evening and be over with before Christmas Day. Forecast for Mammoth; All Snow top to bottom. 12 to 18 inches in town and 18 to 24 on the Mountain. Probabilities 80%
- The will be a break Christmas Day with next storm moving in Christmas Day Night. Moderate intensity with amounts about 6 to 12 in town and between 12 to 18+ on the mountain.
- Third Storm near New Years Eve.
MJO Rimm showing amplification in Phase spaces 8/1 in both JMAN and GFS, but not In ECMWF. So why is the European models not picking up on the tropical convection near the Dateline next week? The hopefully the CPC will highlight this in their discussion today.
As a comment, the fact that the JMAN (Japanese model and GFS are consistent with the return of MJO or at least a Kelvin Wave in this region enhancing tropical convection is worth considering from the stand point of a return to a blocking pattern with either the negative phase of the EPO or WPO. This would increase confidence for a return to a similar pattern in December that brought a lot of rain to Northern CA. However in January, that may end up being a bit stronger and possibly colder. The pattern is highlighted by a split flow out over the central pacific, another active Kona Low; a strong positive height anomaly near the Bering Sea or Aleutian’s.
Tuesday PM Update: The CPC has indicated that the incursion into Phase space 8/1 is due to a Kelvin Wave and is not MJO. So no major blocking expected to MJO.
More later in my Letter Wednesday Night for Thursday AM.
Dr Howard and the Dweebs…………………..:-)
Milder weather on the way before major pattern change occurs….Christmas Weekend to be cooler then normal…With a slight chance of snow showers…..
Sunday December 18, 2016
Posted at 3:47 pm by Howard
Contrary to last nights post, both ECMWF and GFS has a moderate short wave approaching the Sierra Friday for moderate snowfall. (6 to 12 inches) The Dweebs are still skeptic on this change…will update Tomorrow.
The GFS has the MJO increasing in amplitude in Phase spaces 8/1. This would argue for the possibility of the return of at least mid latitude blocking south of the Bering Sea by about the end of the year or the first week of Jan. This would be a wet pattern for the west coast. The only problem is that the ECMWF does not have it and so what the GFS is picking up on is questionable at best.
Just to Ad to the last paragraph, The JMAN is also indicating a rise in RIMM signal in phases 8/1. This is getting interesting. If the ECMWF come around to the same, will get ready for some real Amplification over the north central pacific and see some very interesting patterns develop!
AR II anyone?
More later after the CPC tropical discussion Tuesday afternoon…
Dr Howard and the Dweebs…………………………….:-)
Although the details are in my weather letter, to be released late tonight or Monday AM, the upper pattern will not support a major precipitation type storm, until very late this year or just after New Years….The Models are just too progressive. This means either NW or Inside sliders with a return to colder weather over Christmas, after this weeks warm up….By around the 1st there is a chance the upper pattern across the north pacific may buckle….with long wave Trofing over the eastern pacific. Highs warming to the 40s this week with lows moderating at resort levels to the 20s by Wednesday. Light breezes over the lower slopes.
Thursday’s storm is slowing down and so is the cold air push into Mammoth……Rain may not change to snow untill after midnight in town Thursday night…..Elevations above 9K should be all snow Thursday Night into Friday with amounts increasing Thursday into Friday…Over 4 feet of snow is possible now over the upper elevation of Mammoth Mtn as Massive AR event unfolds for Thursday night into Friday Morning….
Tuesday December 13, 2016
Posted at 9:45 am by Howard
Friday Afternoon 3:00PM
Upper Trof Axis has pushed through with cold northerly flow now. Looking at a 3 dog night with lows 0 to -10.
Finally Tally… (EQ) 5.13 inches of water (Mammoth Mt) 2.86 inches of water at the Village at Mammoth
39 to 56 inches on Mammoth Mountain; Total Base Depth 54 to 132 inches.
6 inches lower elevations of Town. About a foot at the VILLAGE
12 to 18 inches near Canyon Lodge.
Cold the next few days with highs in the 20s…
Lows -10 to 0
Next storm about Friday..
Tuesday Night: 9:50PM
Possible High End Wind event for Mono County Beginning Wednesday night into Thursday Mid Day….Highway 395 Long Valley, north to Walker under the gun for wind gusts up to 100MPH late Wednesday night through Thursday mid day.
Heavy rain possible along the lee of the Sierra Thursday night below 8500 feet with the snow level crashing after mid night. 10 to 20 inches of snow possible over the lower elevation’s of town while upper elevations of town may get 2 feet plus, depending upon snow level. This would be near Canyon Lodge.
Remember, this storm is all about the snow level. About 5 inches of water is expected Thursday into Friday. If for some reason the snow level verifies 500 to 700 feet lower, the town will be buried…with possible R3 conditions.
The event is still about 48 hours away. Will update late Thursday morning.
The 12Z GFS guidance this morning continues the trend of slowing the storm down and most importantly slowing the cold air from invading the Town of Mammoth. All the while, the precipitation continues through the event. What this means is that although the storm is getting a bit wetter with more QPF, it may stay rain longer in the Town of Mammoth before turning to snow. In that we are a good 48 to 60 hours away from the precip event, the Dweebs are backing off on snowfall amounts in Town to between 10 and 20 inches, but increasing amounts for the upper mountain to 4 feet by Friday afternoon…..The snow level will be “about” 9000 feet Thursday afternoon lowering to 8000 by Thursday night then crashing to the Mono County Valley Floor after midnight Thursday…..
The weekend will be dry and cold. Highs in town in the low 20s and lows around zero to 5 above at night.
it appears that we will have some very nice weather the week prior to Christmas…then a series of inside sliders between about Christmas Eve and New Years. These are cold storms with generally light amounts of snowfall. (1 to 6 inches) Another point to make here is that there are signs that the pattern will retrograde slowly the last week of the year and so we may be looking at another major storm by the 1st week of the new year. I have said it before several times, and I will mention it again. The Atmospheric River events of the past 2 months will most likely repeat itself again later in January or early February. The negative phase of the WPO will likely rise its ugly head again but the next time, it may be on steroids…..
PS. There was a very famous winter in Mammoth Lakes associated with the -WPO….If you research the 500mb reanalysis charts, what you will find is an uncanny resemblance of the pattern of the Winter of 1969 to the one that we just went through and one that may reemerge January or February of 2017.