Early August Comparative
Weak/Moderate El Niño
Seasonal Rainfall Climatology
(2002-2003 to 2018-2019)


 This climatology is designed as a quick reference to allow users to see patterns, or non-patterns, between "similar" weak and moderate ENSO (El Niño Southern Oscillation) warm Sea Surface Temperature (SST) events using the NASA JPL Sea Height Anomaly products. My initial takeaway is that by looking at the bigger picture and not just the equatorial Oceanic Niño Index (ONI) data, may give us a better idea of the potential effects from one season over another in terms of winter precipitation.

The data here is partially a subset of that contained in "El Niño Winter Precipitation &
Temperature Climatology
" (http://ggweather.com/enso2016/us_elnino.html. For a breakdown of California Precipitation during El Niño events see "Climatology of El Niño Events and California Precipitation" (http://ggweather.com/enso/ca_elnino.htm). In both documents there is a very wide range of solutions, even within a single category like "weak El Niño".

Like any similar climatology, the usual caveats apply that this is simply a record of past events and not intended to be a standalone forecast tool.

 Jan Null, CCM
Winter ENSO Type MJJ ONI Max ONI Early August Pacific
Sea Ht Anomaly
Winter (Nov to Mar) Precipitation
2018-19  Weak El Nino 0.1  --     --
2014-15  Weak El Niño  +0.2  +0.7    
2009-10  Moderate El Niño  +0.4  +1.6    
2006-07  Weak El Niño  +0.0  +0.9    
2004-05  Weak El Niño  +0.3  +0.7    
2002-03  Moderate El Niño  +0.7  +1.3  
Questions, comments or suggestions. 
Copyright © 2018, 
Golden Gate Weather Services
Reproduction in full or part is prohibited without