Cold inside slider brought some light upslope last night…..Light Mono Lake effect probably helped……Nice weekend shaping up with light winds followed by Storm Tuesday

Lee Vining and June Lake picked up a little lake effect over night. Infact some lake effect was still occuring at this time.  West coast upper ridge to begin reacting to pattern change as strong height rises are now occuring near the dateline and a deepening trof is digging south along 150w. The effect upon west coast upper ridge off shore are profound this weekend. The off shore ridge gets flattened with its high heights squashed into the west coast beginning Friday as it gives us a beautiful weekend! Winds will be light this  Friday, Saturday and Sunday with highs in the 50s Saturday and Sunday at resort levels. Heights peak out Saturday at 00z Sunday and temps will reach into the low 70s in Bishop Sunday. (Golf anyone?)

The next shoe to drop will be the rapidly approaching lead short wave with a fair amount of subtropical moisteure. The timing from the GFS seems pretty good now with the energy expected to come through Tuesday. Cylke’s Law says 12z Tuesday as the 1st iso bar reaches 150E at 12z Friday morning. 96 hours of propagation says energy to come through 12z Tuesday.  So snow fall could begin any time after Midnight Monday night. 500ht Heights are around 552dm at that time, so a snow level around 6000 to 7000 feet to begin with seems good depending upon the dew point and 700mb temps. The nature of the moisture is subtropical so it may end up a bit higher to start with. At the moment…..the isentropic surface along with the front slide through Southern Mono during the afternoon Wednesday. With some additional energy coming through Wednesday night.

A following shot of energy comes off Japan about the morning of the 14th. Although it really does not spin up for another day. Will watch that one the next couple of days….



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.

Ensemble members rapidly increasing trend toward wet pattern for California by Mid Month…Subtropical tap/connection very possible with set up….

Beautiful weekend shaping up…still gusty NNE winds over the sierra crest expected.  Expect highs in the upper 40s and low 50s this weekend with lows in the teens and 20s. Light breezes will be the rule for most areas excluding the sierra crest.

Outlook:

Next inside slider is headed for the Great basin Tuesday. Winds will pick up again with colder weather Tuesday into Wednesday. Highs will return back into the 30s.  The new 12z GFS has the system digging a bit further west now and so a dry back door cold front is expected with strong north wind for the Owens Valley Tuesday afternoon/night.  The weather looks milder Thursday into Friday.  Expect  increasing wind over the upper elevations that next weekend.  

LONG RANGE:

Over the past two days there has been a rapid increase of ensemble members showing a pattern change for the central west coast to a stormy one.  As usual…the timing is different between global model’s ECMWF and GFS. The ECMWF is faster with the change bringing snow to the Mammoth high country as early as the following weekend with the GFS holding it off until the following Monday the 14th.  Using the timing of Cylkes western pacific surface bomb 96 hour rule, the first surface system moves off Japan and spins up the night of the 10th…..so it energy should propagate through the west coast the night of the 14th (Monday). Then another stronger rapidly intensifying surface system moves off Japan the night of the 13th, and so its energy (propagate) would be expected to come through the west coast the night of the 17th based upon this mornings data snap shot. 

The good news is that the upper ridge at this time is forecasted to develop a REX Block signature and is expected to locate between 170w to 180 west. The tropical upper low that is part of the REX block is located about 28N and just east of the dateline. Strong convergence with the easterlies is hinted at, with a train of thunderstorms developing north of Hawaii the night of the 11th into the 12th. This tropical/subtropical moisture may get entrained into the first system headed for the Pacific northwest. As the polar jet slides south, the fetch may follow into California the week of the 14th.

Highlights:

Because of where the upper long wave ridge is setting up….This pattern is good for the development of tropical moisture which may entrain subtropical moisture and involve the confluence of both the polar and subtropical jets into California.

The upper ridge is still in a favorable position as late as 384 hours out and so an active pattern may continue once started, into the 3rd week of February.

Note:  We still have a long way to go time wise, and thus a lot can happen between today and next week. The Dweebs will keep good thoughts and hope that the models still show that a good dumping is in store for our area by mid month.


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.

Moderating temps over the weekend……Continued dry through the middle of next week….Pattern Change Still Looks Good

The cold pool of Arctic air that flushed through the CONUS’ west and mid sections yesterday was centered over New Mexico.  This is expected to spin up an upper low today over northern MX and is expected to give the SE quite a drenching with another ice storm possible over the next 5 days.

Back west…were still looking for our next big dump. One thing is for sure, it won’t happen this week and most likely won’t happen through the middle of next! Sounding forecasts show warming at 700mb the next two days with highs in Mammoth at 8000 ft  in the low 50s Saturday, Sunday and Monday.  There is still a strong surface gradient as well as upper level support the next couple of days, so it will remain windy over the crest.

Next Week:

Another inside slider seems probable as the eastern pacific high amps along 135W and another 1046mb surface high slips south from western Canada into Montana. So far the 540Dm thickness  isohyet remains over east central NV so this should not be as cold as the system last Monday. However,  the gradient’s will  tighten up again and no doubt it will blow over the crest again by Tuesday/Wednesday.

Beyond Wednesday is the big question. The Dweebs have been touting a pattern change for quite a while now for the middle of February. The models have been playing hide and seek with the prospects of another wet pattern setting up.  We are approaching the end of another 21 day cycle of 42 days since the first few day of January which the Dweebs have counted as the end of the Wet pattern of December. The Dweebs also  indicated in one of the December discussions that patterns often times repeat themselves over the course of a particular wet season. Will the next pattern to wet be a repeat of the December loader busters with record heavy wet snows for the Sierra?  Time will tell…

What I am watching:

1. Looking at this mornings ensembles SEE:  http://www.meteo.psu.edu/~gadomski/ENSHGT_0z/ensloopnew.html

You can see that for the 240 hour period only 3 out of the 12 ensembles offer any hope of a significant pattern change. However by the 288 hour it increases to 5 out of 12. Not great but encouraging….

2. Next week begins a period of a series of deepening cyclones coming off Asia….with their track shifting south later in the week to eventually coming off Japan. There is one  pertictular surface cyclone that spins up off Japan and becomes a super bomb about the 11th of February. This should enhance the process of retrogression as the cyclone builds an 500mb  high back between the dateline and Kauai. This is sort of the pattern that developed last December. The scenario included a REX Block  with a tropical fetch that became confluent with the polar jet south AK.  See the new 12z February 3rd, GFS North pacific 500MB.     http://ggweather.com/loops/gfs_12z_500npac.shtml

Additionally, it is curious that the Wheeler-Hedon Phase Space is forecasted to move into the same phase space as last December. See:    http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

With all of the above said, this time the AO Arctic Oscillation is in the  positive phase and so the downstream High Lat blocking is not supportive. Will that make a difference? The Dweebs do not know……

Time will tell……

Next week will be quite interesting as to what kind of a wet pattern change will develop…..


Dr Howard and the Dweebs……………………………..:-)




————————————————-
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.