This figure shows the historical probability (given as a percentage) of seasonal (Jan-Mar, Apr-Jun, Jul-Sep, Oct-Dec) station precipitation totals falling within the upper (wet) one-third, middle (near-normal) one-third, or bottom (dry) one-third of the historical (1901-1990) distribution given the state of ENSO (El Niño, Neutral, La Niña) during that same season.
Here, the ENSO state for each season is determined by the seasonal average of the NINO3 SST index. If the seasonal average NINO3 SST index is in the top (bottom) 20% of the historical distribution for the season, the ENSO state is classified as El Niño (La Niña). The ENSO state is Neutral if the NINO3 index falls between the 20th and 80th percentiles of the historical distribution. Use the controls above the figure to select the season, ENSO state, and precipitation category of interest.
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