Scattered severe thunderstorms capable of producing damaging winds, large to very large hail and a couple of tornadoes will be possible Saturday afternoon in the Upper Midwest and Great Plains. Stronger storms may produce heavy to excessive rainfall. Simmering heat will impact areas from the Southwest to the Gulf Coast and Southeast this weekend. Heat indices may exceed 100 degrees. 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