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Jim Byrne KCOY Weatherman: El Niño Southern Oscillation Diagnostic Discussion March 2018

Read the latest ENSO report by the NCEP with Jim Byrne. The former KCOY Weatherman is into golf and cares about education, environment, and science and technology.

In the latest weather report prepared by the Climate Prediction Center of the National Centers for Environmental Prediction, equatorial sea surface temperatures, (SSTs) have been found to be below average across the central and eastern Pacific Ocean. Jim Byrne, a former KCOY Weatherman, explains this is the backdrop from which the NCEP has announced that La Niña conditions are present.

El Niño and La Niña

Based on the study of the NCEP, most of the equatorial Pacific has been experiencing near-to above average SSTs from mid April to July 2017. The following month, the above-average SSTs continued to dissipate, and by September, there were negative SST anomalies in the east-central equatorial Pacific. Now the SSTs have returned to near average. Jim Byrne explains that El Niño episodes are often classified by measuring the sea surface temperatures.

Based on the definition of the National Centers for Environmental Information, when the equatorial Pacific Ocean experiences at least five consecutive overlapping 3-month sessions where the running mean of sea surface temperature anomalies in the Niño 3.4 region are above the threshold of +0.5°C, there is an El Niño phenomenon. Conversely, Jim Byrne adds when the 3-month running mean of sea surface temperature anomalies are below the threshold of -0.5°C, a La Niña phenomenon occurs.

The Niño 3.4 region has been ranging from 0 to -1.2ºC since August of last year.

Oceanic Niño Index

The report by the NCEP also covered the Oceanic Niño Index (ONI), which is the principal measure for monitoring, assessing, and predicting the El Niño southern oscillation. For El Niño, there should be a positive ONI greater than or equal to +0.5ºC, while La Niña has a negative ONI less than or equal to -0.5ºC.

Stay tuned to read more from Jim Byrne, former KCOY Weatherman.