Snow Showery Conditions This Morning and Breezy Weather Developing as upper Jet backs from the Northwest……Slow Warming trend into the weekend now….The weather next week should hold though Tuesday…..
Wednesday October 24, 2012
Posted at 9:23 am by Howard
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……………………:-)
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.
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…….
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.
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.