El Nino forms, expected to strengthen, say NOAA forecasters

Source: NOAA

NOAA’s National Weather Service announced today that El Nino has developed in the tropical Pacific, and issued an El Nino Advisory. El Nino, the warm phase of the El Nino Southern Oscillation (ENSO), is predicted to intensify to a moderate or strong level this fall. Forecasters predict a 63% chance of sea surface temperatures exceeding 2.0°C in the Nino-monitored region of the Pacific. If this threshold is surpassed, NOAA considers the event a “very strong” El Nino.
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Usual impacts of El Nino can include:

Stronger upper-level winds that tend to suppress storm and hurricane development in the Atlantic Basin, while weaker winds tend to enhance tropical development in the eastern and central Pacific basins.
Stormier weather is more likely in the Southern U.S., with chances of both rain and snow increased during El Nino winters.
High tide flooding could become a higher risk in parts of the U.S., especially on the West Coast.
Changes in the migration of fish and other oceanic organisms, with warm water species moving north while cold water species move farther north or into deeper waters. These behavioral changes impact growth, survival, and reproduction.
Past El Nino episodes have also enhanced the formation of harmful algal blooms along the U.S West Coast.

A new way of monitoring ENSO
In February, NOAA officially adopted the Relative Oceanic Nino Index (RONI) for monitoring sea surface temperatures and forecasting El Nino and La Nina events. Whereas the traditional Oceanic Nino Index (ONI) uses a static 30-year period of recorded ocean temperatures to calculate departures from average, RONI evolves from month to month, making this index more reliable for identifying El Nino and La Nina events.



Read more: https://www.noaa.gov/news-release/el-nino-forms-expected-to-strengthen-say-noaa-forecasters