Well above normal temperatures are forecast to shift from the northern Plains through the Northeast U.S. over the long holiday weekend. A few strong to severe thunderstorm will be possible as well along with a potential for excessive rainfall. A tropical or subtropical depression could form off the Southeast U.S. coast over the weekend while drifting northward to northeastward. Read More >
El Niño: A warming of the ocean surface, or above-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to become reduced while rainfall increases over the tropical Pacific Ocean. The low-level surface winds, which normally blow from east to west along the equator (“easterly winds”), instead weaken or, in some cases, start blowing the other direction (from west to east or “westerly winds”).
https://psl.noaa.gov/map/clim/sst.anom.anim.year.htm
Northern Sierra Precipitation (8-station Index in Sacramento Basin)
Central Sierra Precipitation (5-station Index in San Joaquin Basin)
Southern Sierra Precipitation (6-station Index in Tulare Basin)
Maps
El Niño 2015/16: A Historical Perspective (NCEI)
U.S. Risk of Seasonal Extremes During ENSO (ESRL)
ENSO across NOAA
El Niño/Southern Oscillation (NCEI)
ENSO Research and Monitoring (ESRL)
Societal & ecosystem impacts