NOAA
Noaa: Pmel: El Nino Theme Page
The National Oceanic and Atmospheric Administration (NOAA) sponsors this El Nino and La Nina resource site that features current and historic information about these weather systems with diagrams.
NOAA
Noaa: Pmel: Noaa: What Is La Nina?
At this site from the Pacific Marine Environmental Laboratory, you can find out the characteristics of La Nina. You can find out about the lastest La Nina and the places it effected. Links are provided for additional information.