Variability of the MJO, as expressed by the amplitude of 30-60 day oscillations of surface pressure values in the tropical west Pacific, is examined for long-term trends and sensitivity to broad scale climate features including the QBO and ENSO, among others. QBU stratified data (ie., 30-60 day power) show a robust tendency for sharply stronger amplitudes for November through February during the east phase and for a March through May maximum during the west phase. ENSO stratified oscillations show robust El Nino linked enhancements concentrated in 45-60 day frequencies during September to November whereas La Nina data tend to become stronger in 30-45 day frequencies during December to March. The QBO linked variations are consistent with the effects of previously suggested mechanisms for QBO-troposphere interactions whereas the ENSO linked differences, though robust in time at any location, show a more complex spatial variability.