The current El Niño has strengthened. The most recent ONI (Oceanic Niño Index) for the September, October, November (SON) period is +2.0 degrees Celsius. This is the second strongest reading for the season since 1950. In 1997, the SON period was recorded at +2.2 degrees Celsius, while 1982 ranked third at +1.9 degrees Celsius.
An El Niño event typically brings wetter-than-normal conditions to the Plains. The first map below shows the departures from normal precipitation in Kansas for the September through November period, while the second shows previous SON precipitation anomalies:
December, through Dec. 21, extends the wet pattern. The outlook for the January through March period continues with a higher probability of wetter-than-normal conditions, and a neutral temperature outlook. The current question being discussed is how long the current El Niño will persist. At this point, the National Oceanic and Atmospheric Administration’s Climate Prediction Center outlook shows a continued El Niño favored through the spring, with neutral conditions likely as we head into summer.
The Climate Prediction Center’s long-lead outlooks have the greatest skill when the ENSO is strongly in one phase or another. The outlooks are least reliable when the ENSO is in the neutral phase, as other global circulation features battle for dominance.
Mary Knapp, Weather Data Library
mknapp@ksu.edu
Christopher Redmond, Weather Data Library
christopherredmond@ksu.edu