Archive for June, 2011

Temperatures to gradually recover this week with some risk of afternoon showers….Above normal temps to arrive late next week?

A weak upper level trof in the mean shall continue over the west coast through the end of this week. The remains of last weekends storm (trof) is expected to come through today, initiating scattered showers and possible thunder. Freezing levels are about 11,000 feet, so it should be rain showers in town and snow showers up on Mammoth Mt later this afternoon and evening.  As temps come up this week, that will steepen lapse rates and so afternoon convection and diurnal showers may occur just about any day this week. Normal temps for Mammoth at 8000 is 70 degrees now. It is obvious that we have been well cooler then normal since Winter. That may be about to change!

La Nina is dead….However the negative phase of the Pacific Decadal Oscillation (PDO) is very much alive and going strong!

The PDO effects California WX differently depending upon the phase that it is in. Warm water over the central pacific (+SSTA) and persistent cold water  (-SSTA) along the west coast and Northeastern Pacific are classic signatures of the negative phase.  The negative phase brings more storminess to California, often times making for longer cooler wet seasons that persist even into June. The upper trofing that we have been experiencing will likely continue to some degree through June. However it will eventually pull to the north as the westerlies weaken through the month of June and July. It is expected that we will remain in this Cold Phase for some time now. Highlights will be a longer June Gloom season this Summer for Southern California, possibly much like what happened last Summer.

Will we turn warm next week?

Here is what the Dweebs are looking at:

First of all Summer has really returned to the mid south, south, then eastward to the Southeast sections of the CONUS for sometime now.

For several runs now the American Global Forecast System (GFS) was been trending toward a large scale change in the pattern for the far west. They weaken the westerlies, and at the same time, lift the long wave trof that has been over the far west seemingly forever, NE over the northern plains. The westerlies actually retreat up into Canada by the 16th! At the same time the Northern Mexican continental high retrogrades while building northwestward into the California the 18th into the 20th. This suggests that temperatures will remain much below normal this week to just somewhat below normal by the weekend. I am expecting low to mid 60s this weekend at 8000 feet. Temperature will actually approach seasonal highs in about a week. (70). 

Thereafter, it gets interesting as the GFS longer range shows 1000-500 thickness building to 582DM by the first day of Summer. That is low 80s in Mammoth and a 100+ in Bishop on the first day of Summer. 

With all this said, the ECMWF ( European) has been much slower or at the least, much less aggressive toward the trend to Summer temps.  However the Dweebs will say that the ECMWF is just beginning to trend that way in the last few days.

From the CPC…..both 6 to 10 day and 8 to 14 day charts are sticking with persistence showing the weather cooler then normal through nearly the first day of Summer for much of California. However with that said, they are giving their forecast only a 3 on a scale of 5 for confidence at this time. (Average)

At the moment, the Dweebs even though we are in a -PDO are banking on a FAB Father’s Day!


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.

Mammoth Mt. Reporting 3 to 6 Inches Of New Past 24 Hours…. Scattered Showers Expected The Next Couple Of Days…..

Near record breaking upper low (PVA) has now crossed the Sierra into Eastern Ca and will shortly be into Nevada via the Owens Valley while the main trof still hangs back over CA. The next minor low is coming down the pike, now off-shore nearing the Or/Ca border. 

Scattered Showers will continue throughout the day today under unstable air aloft. The next system does not have the moisture that the former system had, but will bring a renewed threat of showers to the Eastern Sierra Tuesday PM.  Temperatures will be in the 40s in Mammoth today climbing into the 50s Tuesday and Wednesday then low 60s Thursday. Lows in the 20 and 30 this week.

Will this be the last big system (for June) to effect the Mammoth area?  So far yes! This may be the last significant gasp of Winter!  At the moment, the guidance shows that weak Trofing will persist into the end of the week with continued below normal temps. Normal for this time of the year is about 70 degrees here in Mammoth. Actually, some years in the past we have gotten up into the low 80s! High temps will move up into the 60s by Thursday.

Longer Range:

The American Global Forecast System is suggesting that a “hot” ridge will develop beginning the early to middle part of next week some 6 to 10 days away. The ECMWF is holding on to the weak troffing over the far west with somewhat below normal temps. (Low to mid 60s)

The Dweebs will be tracking the change in the pattern this week and and will let you know if Summer will arrive on time from a Meteorology point of view!  😉


Some comments from WSFO FAT:

FRESNO RECEIVED 1.16 INCH OF RAIN ON JUNE 5TH. ALTHOUGH THIS DID NOT BREAK THE RECORD FOR THE DATE /1.30 INCH IN 1993/…IT DID BRING THE MONTHLY TOTAL TO 1.35 INCH FOR THE 4TH WETTEST JUNE ON RECORD. THE SEASONAL TOTAL FOR FRESNO THROUGH JUNE 5TH IS 16.95 INCH FOR THE 8TH WETTEST RAINFALL SEASON ON RECORD.

Dweebs Comment: This is signifacant for Mammoth as a lot of our weather come via the Fresno and San Joaquin Valley. 


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.

Stationary Upper Low Getting Ready To Make Its Move East….Get Ready For Some Serious WX…Late Today/Tonight!

All the Guidance points to some exciting weather here in the Southern Mono County area later today through tonight. Although HPC puts the Bulls Eye QPF north of our area The next 24 hours…..The Dweebs can not help to notice that in the 12 hour 12z WRF at 300mb, that a 110knot upper jet is on shore about Paso Robles and pointed torward Mammoth Mountain! Mammoth remains in the front left quad or best area of UVM through 06z tonight.  I would imagine that we could see a period of heavy rain and snowfall beginning tonight through early Monday morning. In fact another foot on top of what fell over the crest the past 24 hours is not out of the question!

Ski patrol reported 3 inches of new over the past 24 hours at 9000 feet and up to a foot on top.  Could this end up a two foot sierra crest June Dumper?

A storm system this deep this far south along the west coast in the month of June is pretty rare. At the moment, (10:00am) Sunday…the center is about 250 miles WSW of Monterrey Bay about where it has been the past 24 hours. 

It appears that the area of best precipitation will be from about Kings Canyon to Yosemite…..or the area directly in the front left exit region of the upper jet. The jet core will drop south to the Sequoia Nat Park this evening so that area will be come under the gun as well. Again the heaviest snowfall will occur just to the north and east of the track of the upper low which will include Mammoth Mt/Lakes tonight!

Although Snow levels will remain above 9000 today…..as Monday morning arrives, the upper center and cold pool will move through Central California as the coldest part of this system moves over head. 1000-500mb thickness lowers 550dm  The snow level will lower to about 7000 feet.  It is possible that at elevations as low as the “Village at Mammoth”,  a couple of inches of snow could be on the ground Monday Morning. Again up to another foot is possible on top of Mammoth Mt by Monday AM.

OUTLOOK:

The upper low kicks east into Nevada during the afternoon Monday. It will be followed by a smaller impulse Tuesday afternoon and so there is chance of some light showers Tuesday as well. 

Another system will drop south from British Columbia to Eastern Oregon Wednesday pm then into Northern NV Thursday then east into Utah Friday, bringing Drier weather to the Eastern Sierra along with below normal temps. Although at this time, there is not another major system in the offering….Weak trofing remains over the Far West through next weekend…..and so temps will remain below normal and there is always a possibly of showers with any weak impulse in our vicinity. 



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.