Mammoth Weather
Brought to you by Howard Sheckter
Brought to you by Howard Sheckter
Friday October 26, 2012
Saturday AM Update:
Fair Indian Summer weather to continue through at least Tuesday….with highs in the low 60s in the Town of Mammoth. The upper ridge will hold through Tuesday and will be slower to move east because of TS Sandy which will have the effect of the slowing the progression of the long wave features across the CONUS. Thus Wednesdays snowfall potential will be pushed back to probably Thursday now.
Additionally, as the system finally moves into the west coast coast Mid Mid week…..it will be running into the mean ridge position centered over the SW. So the front will weaken rapidly as it progresses through California Wednesday into Thursday. The Dweebs do not expect much out of the front. In fact it may just bring some showers Thursday and that’s it. Antecedent conditions will be pretty warm and so snow, whatever falls will be over the very upper elevations then falling into town after the fronts through. Will take a look at the freezing level in a few days. Again this may bring any ware from some very light accumulations to nothing…..
Updates early next week……
Dr Howard and the Dweebs……………………………………:-)
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Snow-making the past several nights continues to add to Mondays Snowfall so that Mammoth Mt opening will be right on time…..
In short….An Upper ridge builds in over the weekend for a beautiful Fall weekend with above normal temps…..Highs about 60 in Mammoth Sunday and mid to upper 70s for Bishop. Night time low will be mild Sunday morning and above freezing in the mid to upper 30s at 8000 ft.
The warmer then normal weather will continue through Wednesday.
Cooler Wednesday along with unsettled conditions leading to a chance of light snow for either All Hallows Eve or a slower solution brings the system in the following day Thursday the first.
Have a great weekend, but pray for the folks on the Central Atlantic coast Monday and Tuesday.
The Dweeber…………………….:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.
Wednesday October 24, 2012
Thursday Update:
Some over running this morning from the NW…. A brief look at 700mb RH for 12zNAM shows an area of 70%Rh over Mammoth this AM, so with the cold air in place would not be surprised to see a few flakes around. With the ridge building in stronger this evening 700RH should diminish and we’ll experience some pretty cold temps over night. The weekend will will warm up. (See discussion below)
Next upstream system begins to move into the area All Hallows Eve and the EC is back with the chance of Rain and Snow. I think that the EC is doing a better job now in the outlook. So plan for the little Trick or Treaters to be extra warm as we may get light snow…..
Dr Howard and the Dweebs……………………:-)
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As forecasted…there were snow showers this morning with breezes on the increase. Based upon the latest vapor wave loop…the bottom of the upper trof has shifted into Nevada while the upper jet has backed to the Northwest. Little moisture is available this far south and so some light snow showers or flurries will continue for a time this morning…mainly over the crest and slightly east. Temps today will moderate into the mid to upper 30s in town while nighttime lows drift down into the teens Thursday AM.
Mammoth MT picked up 17 inches of snow storm total, according to Alex Clayton who manages snowfall amounts for the Mammoth Mt ski patrol. According to Cliff Man of Mammoth Mountain, the snow guns will begin shortly to add to the snow pack as Mammoth Mountain makes plans with their 2012/2013 season opening Thursday, November 8th!
The forecast models over the next several 5 to 7 days indicate that the present trof will continue to progress east while the off shore upper ridge slowly builds into California by Sunday. So expect a slow warming trend through Sunday. Initially, it will be chilly and breezy the next few days with fair conditions over the weekend and very light breezes. Temps may reach the upper 50s in town by Sunday with the ridge axis over us. Night time lows will be mostly in the teens and 20s through Friday then soar over the weekend over the higher terrain as strong subsidence and inversion conditions develop. The 0C isotherm at 700mb takes a hike well north of the area Saturday and Sunday with +6C at 10,000 feet Sunday at 12z. That will allow nighttime lows at 8,000 feet back into the 30s Saturday and Sunday. Lower elevations will be cold in the teens and 20s.
Outlook:
The upper ridge progresses east while the upper flow coming in from the pacific flattens early next week. The next upstream system Tuesday will bring precip to Northern California and eventually the Northern Sierra by All Hallows Eve. The latest ECMWF 00z Wednesday run has backed off the idea of some light snowfall for the Mammoth area around the 31st/1st for the time being….keeping the storm to our north. So well play a wait and see if that changes…….
MJO:
The Madden Julian OCC is in phase 2 now which for this time of the year highlights a bit warmer then normal temps. However with the present snow cover, that is probably a bit unlikely for our area. There is also a slight bias to the positive side for precip. However, at this time of the year the signal is very weak.
Notes on the QBO:
Here is some interesting notes about the QBO and how it relates to its phase, strength, what it means and where it may go.
The QBO quasi-biennial oscillation (QBO) is a high level stratospheric wind at the very top of the atmosphere ( 30 mb) that exists over the Equator that oscillates from East (negative QBO) to West ( Positive QBO). A full cycle can take anywhere from 18 to 30 months.The strongest positive values are usually around +15.00 or so while the strongest negative values will exceed -25.00 or so. The QBO winds work there way down into the Lower levels and affect weather patterns. Strongly POSITIVE QBO values correlate to Non Blocking weather patterns in the Jet stream. Strongly Negative QBO values in the cold season Months = +AO and +NAO patterns
However, QBO values that are “weak” (-10 to +10)
Strongly favor Blocking Patterns over the Northern Hemisphere in the cold season months of November through March.
The Dweeber……………………..:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.
Tuesday October 23, 2012
Many Forecasters forget early in the season, especially after a long warm Summer, a drier then normal winter, that Mammoth Mt and its immediate area have a very special relationship when 700MB winds blow from the WSW. This storm was a classic case in point of how special local topography (land features), and Orographics (Mountain Effects upon moist winds) can play in forecasting snowfall and QPF. The wettest model, the ECMWF last Sunday, forecasted an inch of precip,(water EQ) just to the west of Mammoth Mt and Mammoth Pass over a 72 to 96 hr period ending Thursday AM. HPC forecasted about .5 to .75 of an inch and several forecasters indicated that was considered wet for the storm who’s upper jet favored the Northern Sierra.
What was actually recorded was close to 2.00 inches up on Mammoth Pass (1.72 according to CRFC), (subject to verification), and at 9000′ (unverified by manual means) 1.8 inches at the Main Lodge. (18 inches of snowfall); .87 inches W/10 inches of snow on Hillside Dr. near the village. Areas east of Highway 395 had little precipitation to speak of.
Mammoth Pass did not get anywhere near the amounts that some west side, Northern Sierra remote stations recorded. It received about double the amount compared to areas like Yosemite Valley (.89). Bridgeport on the other hand received .15 of H20, indicating how shadowed areas to the east were.
Currently:
Winds were still westerly this morning at 700mb (10,000ft) and RH at the same level was about 60% to 70% but will decrease to 50% by this afternoon….so snow showers will continue over the higher terrain this morning but will diminish this afternoon. The next and last wave comes in early Wednesday morning. The flow at 700mb begins westerly but quickly shifts more northwesterly during the mid to late morning as the long wave Trof shifts into the Great Basin at the same time. Thus we loose our orographics pretty quickly after Sunrise Wednesday. The best chance of snowfall with this system will be around Sunrise, as later in the morning the upper flow becomes more northwesterly.
The weekend outlook is for partly cloudy but fair weather under a northwest flow. In that the upper high (500mb), remains well to our west, and apparently does not come in anytime soon, it will remain breezy over the upper elevations with highs in Mammoth in the 50s…lows in the 20s.
Next Trof about All Hallows Eve
Although it is about 10 days away…The Euro is saying that it will bring about 6 to 7 inches over the crest by November 1st. Lets see how well it does from a distance!
Dr Howard and the Dweebs…………………………….:-)
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Reference Glossary of Weather Terms
Disclaimer: I have been a hobbyist meteorologist for over 30 years here in the Mammoth area and I do this for my personal enjoyment. The National Weather Service saves lives every day . . . I do not. When making important planning decisions please use information provided by the National Weather Service as they are the most knowledgeable and accurate information source available today.