Warmer, Milder Weather On The Way…..MJO Still Rising!

The key feature in the western hemispheric pattern over the next 7 days is the big Bering Sea-Alaskan block that is retrograding westward toward and over Siberia, Russia. This teleconnects well with the west coast rising heights forecasted by the global models. This should give us a nice period of January thaw the second half of this week into early next week.  Temperatures will climb to the mid 60s in Bishop by Saturday and into the 40s beginning today for Mammoth.  There will still be a few periods of over-running about Thursday/NGT and again some clouds Sunday.  The models only give us a scant  of QPF Thursday/Ngt (.01 to .02)

Here is your high temperature forecast for Mammoth through weeks end. This is for the Town of Mammoth (TOML).   Wed43/Thur43/Fri44/Sat45/Sun48/Mon48/Tuesday48.

Night time lows will be in the 20s for the most part this week until Sunday and Monday morning when they may only get down into the low to mid 30s…hence the January Thaw!

Good time to plan to break up ice dams and ice and snow off areas of decks and walk ways as the ice will be much more easily removed by this weekend!


Longer Range:  (Next Week)

The models sharpen the west coast, upper ridge the early part of next week. All models have an inside slider type system that will dive into the Rockies mid week.  The warm temps over the Eastern Sierra for the time being is expected to hold through next Tuesday afternoon. However an abrupt change in the pattern will send a blast of cold Arctic air into the Great Basin a week from this Wednesday. An Arctic Front  is expected to enter the Pacific Northwest Tuesday and move through Mammoth Thursday morning. This will probably bring  increasing winds as early as Tuesday night with stronger winds Wednesday into Thursday morning. There may be a period of up-slope snowfall Wednesday night. Strong “convergence aloft” in the left rear entry area of the upper jet and NVM should build a pretty strong surface high over Idaho (1040mb)with a tightening NE gradient along the Eastern Slopes of the Sierra. Strong up slope North Easterlies? It appears to be a quick event in any case.  What is additionally interesting is that this is but a very small chunk of modified Arctic air compared to the monster frigid Arctic air mass that is forecasted to come slamming down from the Arctic later next week over the North-Eastern US. It appears to be the Coldest Arctic Air Mass in a long time.  The coldest air will effect areas like the Great Lakes region south and eastward. A 500mb-1000mb thicknesses pool in the Mid 460s is impressive over Central Canada Thursday afternoon a week away! Today’s 12z Wednesday GFS has the 474Dm  Thickness clipping the northern Great Lakes area a week from this Friday…then heading for upstate NY into New England……..Brutal!


MJO:

Still Intensifying and even growing stronger then forecasted for this time. The Dynamic models are adjusting.

What does the MJO (Madden Julian Oscillation) do to the pattern over the pacific?  It depends upon where it is, and how strong it is.  As the “enhanced portion” (rising air….enhanced rainfall) moves into the western pacific, it modulates the westerlies. The GFS should begin to show a change in the pattern later this month. 

If it all works out…..As the enhanced state of MJO moves into the Western Pacific, (About the 25th of January} watch for strong amplification of a Trof-Ridge pattern with a large jump in amplitude in the west coast ridge. This feature should then build north up over Alaska with time….eventually becoming a large cut off upper Anti-Cyclone  over AK.

Phase space 7 into 8 the Atmosphere is in the Pseudo El Nino State. Expect a lower latitude upper Jet splitting off and under cutting the westerlies during the mature stage with the chance that a precip event will come to the west coast. Timing….sometime between the end of January and the first week of February. Good reading below…..


Remember that there is no guarantee at this time that this will happen. It is still quite speculative. However….this will be a lot of  fun to follow!

MJO Education:

1. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/MJO_1page_factsheet.pdf

2. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/MJO_summary.pdf

Specifically in the #2 PDF file, there are some excellent visuals toward the very end of the file.


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.

Looks Like A Week Of Nuisance Weather…Then MJO rising next week…..possible stormy period the end of January into the first week of February.

A strengthening upper jet into the pacific northwest brought light warm advection snowfall to the eastern sierra this morning. About an inch has fallen on Mammoth Mt and a dusting in town. Expect another inch or so to fall throughout the day today and tonight. In that heights will be gradually rise this week, we can expect warmer temperatures. Highs in Mammoth in the mid 30s today then low 40s Wednesday and Thursday followed by upper 40s over the weekend and approaching 50 by Sunday/Monday. This is setting the stage for a possible January thaw.

Precipitation will be very light all week with periods of gusty winds mostly confined to the upper elevations……hence “Nuisance Weather”!


MJO:

Yes…there is confirmation now that we have a strengthening MJO.

See: http://cawcr.gov.au/staff/mwheeler/maproom/RMM/phase.Last40days.html

Note:  The location within the graph of the MJO is on the border between phase space 5 and 6. It is possibly 1 to 2 standard deviations of normal.  The number 10 represents the day of the month which is currently January. The further the distance between the center of the chart to the outer end the stronger the MJO.

Now look at the Dynamic Model MJO Forecasts:

See:  http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

One can see that the GFS forecasting system is forecasting quite an impressive MJO.

And just as importantly……

The location of the MJO moves into a very-very favorable teleconnected area, Phases (7 and 8 ) (El Nino Like).  Historically, this area has teleconnected well with strong west coast storms, including but not limited to the dreaded Pineapple Connection.  Although it is still to early to make forecasts and the fantasy charts of the GFS has of yet,  not picked up on any significant amplitude. They do have quite the strengthening lower latitude upper jet beginning to extend eastward north of Hawaii toward the west coast by the 21st.  

Again..the dynamic MJO forecasts indicate a strengthing signel during the upcoming week with eastward propagation through the end of next week. Most importantly….the “Enhansed Convective Phase”  is forecast to be entering the western hemisphere about the 25th of January. This may set the stage for a possible stormy period for the west coast toward the end of January and into the first week of February.


Stay tuned WX Dweebs……It may get quite fun!


A comment from the Climatic Prediction Center:

1/10/11

ANOTHER CONSIDERATION FOR THE WEEK-TWO PERIOD IS  THE POSSIBILITY OF A SIGNIFICANT MJO EVENT WHICH IS STRONGLY SUGGESTED BY GFS  FORECASTS.  THE PHASE OF THE MJO IS FORECAST TO BE IN A REGION OF CRITICAL  TELECONNECTIONS TO THE CIRCULATION OVER NORTH AMERICA, HOWEVER AT THIS TIME,  IT IS JUST TOO EARLY TO FACTOR ITS INFLUENCE INTO THE FORECAST WITH ANY DEGREE OF  CONFIDENCE, OTHER THAN TO REDUCE CERTAINTY.


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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.

Cooler Weather and Quite Breezy Over The Upper Elevations Sunday

Just a quick update this morning…

It’s very breezy over the upper elevations this morning. With the ambient temperatures in the 20s today dress warmly up on O’l Woolly!

Strong upper jet NW-SE  Cutting through Nevada today. Dry cold front will slowly make its way through southern Mono County later this afternoon. A wind shift should occur for the Owens Valley tonight and so expect north winds to really pick-up this evening. (15 to 30mph)

Highs in the Town of Mammoth will be a bit higher then forecast as the front has slowed down. As of this writing,  the town has probably peaked on temps  for the day (33 degrees)…..while night time lows will drop into the single digits. Light breezes are expected for the TOM.

For the coming week…the main storm track will be well into the pacific northwest. For the Central Sierra,  expect mostly light to possibly moderate warm advection type (Isentropically lifted) precipitation. So some light snowfall is expected Tuesday and Tuesday night. There will be some chance of light snow throughout most of next week. Snow levels will rise most of the week. High temps will go from the mid 20s Monday to the 30s by Tuesday into Thursday then into the 40s by next weekend. There is still a possibility of a January thaw the following week.

The key to our longer range I believe is whether or not a MJO develops week 2 and modulates the westerlies as the NAO is going to be in the positive mode toward the longer term.

See: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

LA NINA is still raging!…….

See: http://weather.unisys.com/surface/sst_anom.gif

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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.