"The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30–90 days) variability in the tropical atmosphere. It is a large-scale coupling between atmospheric circulation and tropical deep convection.[1][2] Rather than being a standing pattern (like ENSO) it is a traveling pattern, propagating eastwards at approximately 4 to 8 m/s, through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself in various ways, most clearly as anomalous rainfall." (Wikipedia) The US-CLIVAR MJO working group has developed diagnostics for objectively evaluating the MJO. Two WWW sites demonstrate the diagnostics: http://www.ncl.ucar.edu/Applications/mjoclivar.shtml and http://climate.snu.ac.kr/mjo_diagnostics/index.htm. Operational centers monitor the MJO and indicies are available at: http://cawcr.gov.au/staff/mwheeler/maproom/RMM/ and http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_mjo_index/mjo_...