2nd Half Of Snow Forecast Busted For The High Country….Nice Break In The Weather Coming Up Beginning Tuesday

What a Season!  Mammoth Mt is reporting 311 inches of fallen snow for the ski season of 2010/2011! The annual average is 343, so were less then 3 feet away from a normal ski seasons worth of snowfall and its only January 3rd!

The Past Storm:

First half the forecast was on the money…the 2nd half a bust!

Systems that are not forecasted to traverse across the Sierra are the ones that are most difficult to forecast snow fall wise along the Eastern slopes of the Sierra.  Mammoth Mt did pick up between 1 and 2 feet with the town 6 inches + between the 1st & 2nd.  The snowfall was primarily warm advection  snowfall by which relatively warmer air over riding a colder air mass was then lifted to create snowfall. The big active band of heavy precip did not make it over the crest yesterday!

The pattern over the next 5 days is highlighted by the redevelopment of the Greenland Block…(-NAO)

and…….

1.  An upper low off the Southern Ca Coast becoming cut off from the westerlies as an upper high builds over the top of it into California.

2.  An easterly flow will be the dominate pattern here in the Mammoth area beginning later tomorrow Tuesday insuring fair but cold weather until about Thursday/Friday when  HT 500 heights come up into the 570s and we loose our chilly easterly flow. We then may get up into the low 40s by Friday.  The off shore upper cut off gets ejected eastward Saturday and will become a major player in the weather across the south-southeastern CONUS. (ice storm?)

3.  Model skill seems to be decent into the weekend when some sort of inside slider drops into the Great Basin Sunday. As a result, no doubt there will be cooling Sunday into the early part of the following week. Possibly some snow showers as well.

THEN:

4. Big questions arrives for the following week with how the big Greenland Block which becomes more of an north central Canadian block will effect the upstream high latitude pattern.  The long range models are all over the place with the evolution of the Alaskan Block and how the Greenland/Canadian Block relates to it. This mornings 12z GFS week two maps are so out to lunch its pitiful. The ECMWF still suggest the possibility of  a wet lower latitude active pattern which would effect California sometime between the 10th and the 15th. This is certainly pushed back several days from from the models earlier forecasts…However,  it is still there and a possibility.


More Later……………………….:-)


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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.

Some Changes In The Longer Range Charts Today

Some really good news and the Dweebs hope that the trend holds as we do not need any more snow here in the high country for now. Just had a peak at the 12z operational ECMWF.

Beyond the current storm that is ongoing….The last two operational runs of the ECMWF have done some back peddling on the potential wet pattern that looked to develop just before the 10th of January. Although the Greenland Block still develops later this week and high latitude blocking is still forecasted to occur over the Bering Sea…the upper high now becomes cut off over AK by the 10th of Jan,  instead of remaining a full latitude Rex Block as the ECMWF showed during the earlier runs a few days ago. Although there is still the possibility of a wet over running storm around the 10th…the pattern does not look nearly as concerning as it did a few days ago during my earlier outlook. The fact that the upper high become cut off over AK with no support to its south and with a subtropical low in the mid latts…. tells me that the pattern will want to ridge up now over the eastern pacific. We may still have a period of over running from the subtropical system from north of Hawaii for a time around the 10th…..stay tuned! Remember this is not all set in stone and there is plenty of time for the models to adjust either way as the Ensembles still lean toward a Ca wet pattern.

What the ECMWF is now showing is a cross polar flow down into the country’s mid section along 100w -40N, that will in effect, empty the polar regions reservoir of Arctic air for a time, sending brutal cold down through our countrys midwest 8 to 10 days away.

Again…..with all the above said…the ECMWF ensembles still look on the wet side from the 10th on.



The Dweeber………………..:-)


————————————————-
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.

Another Winter Storm Warning Hoisted For Our Region…..This Time For The Owens Valley Too!

An approaching upper level low spread more snow into the Mammoth area the past 24 to 36 hours. Mammoth Mountain has reported some 11 to 18 inches during that period.  Most of the snowfall has been of the over running type or warm advection snowfall. However, that is about to change as the current slow moving system makes its move inland into California today.

The upper center is currently located about 125 miles WSW of Monterrey Bay. A large band of heavier precip is currently noted by SFO Radar that is moving ahead of the upper low across Central Ca and into the San Joaquin Valley.  This band should kick off the moderate to heavy snowfall over the Mammoth area by this afternoon. Some snow showers have already begun in the southern portions of the Owens Valley near and north of the Kern County border.

The Models forecast this upper low to move slowly inland into Central Ca this afternoon with good dynamics as the front left exit region of an 110 knot jet traverses through south Central Ca.  NWSFO-RNO is expecting “up to” an additional 32 inches by Monday over Mammoth Mt.

Winter Storm Warnings are also hoisted for the Owens Valley for heavy snow this afternoon and a Winter Storm Watch is out for the Kern County deserts beginning at 4:00pm into tonight!


Traveler’s be safe!  Take warm blankets and food for the trip!


Longer Range:


Looks like a nice break Tuesday through Friday.  Some changes in the longer range in how the Greenland Block eventually evolves as well as the eventual development of the Northern mid Pacific Block…..Stay Tuned!……………………:-)


The Dweeber……………………….:-)



——————————————————————————–
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.