(MJO) Madden Julian Oscillation

[cycloneye]

Many may be asking,why the EPAC is very active at this time and the answer is this important factor when is in a negative (Green Lines) is favorable for tropical development.When is in a positive (Brown Lines) phase it does not favor tropical development.

Anyone has more links to the information of the MJO apart from this graphic I posted?

[RL3AO]

[wxman57]

There's a write-up I did on MJO in 2003 or 2004:
http://myweb.cableone.net/nolasue/mjo/

This is probably one of the best sites for MJO info. It's a PowerPoint presentation that's updated weekly on Mondays:

http://www.cpc.ncep.noaa.gov/products/p ... update.ppt

And then there's the MJO realtime forecast page:
http://www.icess.ucsb.edu/asr/mjo_forecasts.htm

The latest forecast (note the buildup of blue (increased storms) over the east Pac and western Caribbean after July 5th):
http://www.icess.ucsb.edu/asr/MJO_current_run.htm

And Paul Roundy's MJO (OLR) page:
http://www.atmos.albany.edu/facstaff/ro ... ec312.html

[KWT]

Is the MJO as important for Cape Verde waves as it is for say homebrew activity in the Gulf of Mexico?

[cycloneye]

There's a write-up I did on MJO in 2003 or 2004:
http://myweb.cableone.net/nolasue/mjo/

This is probably one of the best sites for MJO info. It's a PowerPoint presentation that's updated weekly on Mondays:

http://www.cpc.ncep.noaa.gov/products/p ... update.ppt

And then there's the MJO realtime forecast page:
http://www.icess.ucsb.edu/asr/mjo_forecasts.htm

The latest forecast (note the buildup of blue (increased storms) over the east Pac and western Caribbean after July 5th):
http://www.icess.ucsb.edu/asr/MJO_current_run.htm

And Paul Roundy's MJO (OLR) page:
http://www.atmos.albany.edu/facstaff/ro ... ec312.html

Thanks 57,you brought what I needed and a little extra with the presentation and writeup.

[wxman57]

Is the MJO as important for Cape Verde waves as it is for say homebrew activity in the Gulf of Mexico?

The MJO is primarily an enhancement for the western Caribbean and Gulf of Mexico region.

[cycloneye]

I am bumping this important thread for those who may not know what MJO is and what it does.One of our resident pro mets wxman57 posted above a few links that explain all about this global factor.Look for his post.See why the Atlantic is not favorable right now for cyclogeneis while the Western Pacific is the contrary.And then in two weeks it will be reversed as the Atlantic will have favorable MJO and the Western Pacific not.

[O Town]

I am bumping this important thread for those who may not know what MJO is and what it does.One of our resident pro mets wxman57 posted above a few links that explain all about this global factor.Look for his post.See why the Atlantic is not favorable right now for cyclogeneis while the Western Pacific is the contrary.And then in two weeks it will be reversed as the Atlantic will have favorable MJO and the Western Pacific not.

Luis why not edit the thread title to include the abbreviated MJO in parenthesis, because if some don't know what MJO is they may not know its unappreviated name of Madden Julian Oscillation and not open the thread at all.

Great write up wxman57, very informative and made MJO easy to understand.

[cycloneye]

I am bumping this important thread for those who may not know what MJO is and what it does.One of our resident pro mets wxman57 posted above a few links that explain all about this global factor.Look for his post.See why the Atlantic is not favorable right now for cyclogeneis while the Western Pacific is the contrary.And then in two weeks it will be reversed as the Atlantic will have favorable MJO and the Western Pacific not.

Luis why not edit the thread title to include the abbreviated MJO in parenthesis, because if some don't know what MJO is they may not know its unappreviated name of Madden Julian Oscillation and not open the thread at all.

Great write up wxman57, very informative and made MJO easy to understand.

Done

[Decomdoug]

Wonderful write up wxman57. Thank You for providing it.

[wafbwx]

I think a lot of people on this board are putting too much weight on the MJO's influence on Atlantic activity. As wxman57's write-up notes, the MJO's influence is much less pronounced in the Atlantic than in the western Pacific or Indian Oceans. Maloney and Hartmann did establish an association between the MJO and activity in the western Atlantic, but there's probably little association farther east because the MJO signal is much weaker. Remember that the MJO is only one of a number of factors that can influence tropical cyclone variability...

I completed a master's thesis this year in which I was unable to replicate the results of Maloney and Hartmann using a slightly different methodology. That's not to say those guys are wrong...because I did discover possible problems with my methodology, but I also believe the association they found may not be quite as robust as their results indicate.

The bottom line is that I would encourage everyone not to think of the MJO as an "on-and-off" switch for tropical activity in the Atlantic. Yes, there is some influence, but storms will sometimes form in a "suppressed convection" MJO. I keep seeing people post that we shouldn't expect anything for the next couple of weeks because of the MJO phase...maybe, maybe not. A lot of other factors will also have a say in that...

[fasterdisaster]

How often does MJO cycle between positive and negative, approximately?

[RL3AO]

How often does MJO cycle between positive and negative, approximately?

30 to 60 days.

[cycloneye]

It looks like the Atlantic will be favorable again by the second week of August,just in time when the peak of the season starts.

[RL3AO]

So much for two weeks in the negative.

[njweather]

So much for two weeks in the negative.

Yep. Seems the Atlantic is favorable yet again.

Though the picture in your post shows the less favorable conditions. The July 28, 2008 image in your original post shows the most recent, far more favorable conditions.

Though as Ortt and other pro mets have said, the MJO has little bearing on our segment of the Atlantic.

[Aric Dunn]

actually the other day I was reading something that said the MJO forecast are at least partially based off of some climatology. I dont remember where i read that but i thought is sounded kind of weird since the waves are tracked ( for the most part) across the pacific? anyone heard that before? it sounds wrong.

[cycloneye]

The thread went to the second page so I am bumping it.The unfavorable MJO is now in the Atlantic Basin.But the favorable or humid MJO will invade the Atlantic after the 15th so fasten your seatbelts peeps.

The blue color is the favorable MJO.

[BigA]

So if I read the map correctly, MJO will become a little more favorable between the 9th through the thirteenth, then significantly more favorable around the middle of the month?

[cycloneye]

So if I read the map correctly, MJO will become a little more favorable between the 9th through the thirteenth, then significantly more favorable around the middle of the month?

Correct,just in time when the peak of the season starts,although some experts dont look at this factor as a significant one.