The Madden-Julian Oscillation is a weather/climate phenomenon near the Equator which can have big impacts on the weather up here in the Mid Latitudes. The MJO has been linked to strong oceanic Kelvin waves, the onset of an ENSO (El Nino) event, and even the development of tropical cyclones. The MJO is something that can help bridge weather and climate and give us an idea what is happening in the future. For example, the location of an MJO wave can also have an impact on our weather (for example phase 8/1/2 is favorable for cold weather in the northeast this time of year).
The MJO has been active recently with a substantial MJO wave that started near Africa and the western Indian Ocean and is now near New Guinea and Indonesia. In the Outgoing Longwave Radiation image posted to the left you can see strong negative OLR anomalies (which is a proxy for convection) now centered near Indonesia. The big question is whether this MJO wave (which has weakened will continue east toward the International Dateline which would teleconnect to a pattern change in North America.
The graphic on the right shows the progression of the MJO (counter clockwise or easterly) from the African coast, through the Indian Ocean, and now toward Indonesia. The wave which was quite substantial and had a high amplitude has fizzled some (the further from the origin – the higher the amplitude and stronger the wave) but it is trucking along toward Phase 5. I expect this wave will continue toward the Dateline and it’s amplitude should increase a bit as it heads toward more favorable Sea Surface Temperatures.
You can see negative SST temperature anomalies between the north coast of Australia and New Guinea which is likely stifling MJO activity for the time being but as the wave propogates east it will run into more favorable SSTs and should increase in amplitude. If the MJO enters into phase 7/8/1 this should favor an increased chance for cold during the first half of December. This dynamical MJO forecast from the GFS ensembles indicates the MJO weakens quite a bit but they have been showing this for the last week or two and that has yet to happen. My guess is that this wave will continue and we will see a pattern change as the convection teleconnects to a different east pacific/north american wave train.