SOI - Precipitation Scatter Plots

Summer/Autumn SOI versus following October-March Climate
(following methodology of Redmond and Koch, Water Resources Research, 1991).

Important points from these diagrams:
  • Not every El Nino produces the same effect.
  • La Nina has a more consistent signal, in general, than El Nino.
  • The relations are not perfect....other things are happening in the climate system.
  • The 1982/83 El Nino does not fit in with the other points in some locations. Patterns for large El Ninos may differ in some ways from typical El Nino patterns.
  • The relationship is lagged. Best associations are found between summer/autumn SOI and the following winter climate, and the following spring and summer streamflow runoff.

    Clearwater R. data courtesy David Garen NRCS-Portland,
    American R data courtesy Maurice Roos, California DWR

    A few locations are shown. Others will be added as time permits.
  • Time Series of SOI (June-Nov, after Redmond&Koch (1991))
  • Reno, Nevada
  • Las Vegas, Nevada
  • California 8-station index (8 Stations in Northern Sierra used by CA DWR)
  • American River @ Fair Oaks (Sacramento) Winter 3-Day Maximum Flow Streamflow
  • South Coast California Climate Division (6)
  • Western Montana Climate Division (1)
  • Central Idaho Mountains Climate Division (4)
  • N Fork Clearwater River (Central Idaho) April-July Streamflow
  • Arizona Statewide
  • New Mexico Statewide
  • Washington Statewide

    Time Series:
  • Las Vegas, Nevada
    Western Regional Climate Center, Dr. Kelly Redmond,