The RMM index is the market standard to identify the MJO. But at times, it struggles with MJO identification when the zonal wind anomalies in the lower troposphere (U850) are out of sync with upper-tropospheric zonal winds (U200). When out of sync, the index can show a weak MJO pic.twitter.com/xFFja5fg5q

— Mike Ventrice (@MJVentrice) February 23, 2022