The National Weather Service (NWS) is predicting an El Niño for later this year, but don’t expect it to end our drought – or even have much of an impact. The NWS has called for a “moderate” El Niño Watch, which means it is unlikely to significantly change our rainfall.
“I would say it does not guarantee any end to the drought,” said Steve Mendenhall, the meteorologist in charge of the San Joaquin Office of the National Weather Service. “There’s no direct correlation between it and above-normal rainfall when you have a moderate El Niño. It’s only the stronger El Niños that produce above-normal rainfall, and that’s not what’s being forecast. It could produce above-normal rainfall, but it could also produce below-normal.”
There have been seven moderate El Niños between 1951 and 2013. Only two produced above-normal rainfall in the Tulare and Kings County area. One led to near-normal rainfall, and four were below normal.
In that same period, there have been four “strong” El Niño’s, with all of them resulting in above-normal rainfall years.
El Niños are the result of unusually warm ocean temperatures in the equatorial Pacific, which have a significant impact on weather conditions around the world. El Niños have increased rainfall along the southern part of the U.S. and in South America, occasionally causing severe flooding in some areas. As a result, the conditions in the Pacific are closely watched and are used to predict the climate in the U.S. and other countries.
The current El Niño Watch was issued because conditions were determined to be favorable for the development of El Niño conditions within the next six months.
The NWS, which keeps an eye on the situation, provides updates every month or so. There is a chance that conditions could change, resulting in a stronger El Niño developing, but again, any hopes it will end our drought appear to be fading.
“The trend has been, from a few months ago, that it has been getting weaker,” said Mendenhall, “but it’s still in the moderate category.”
In its June 5, 2014 El Niño-Southern Oscillation (ENSO) Outlook/Forecast, the NWS stated, “Forecasters at NOAA’s (National Oceanic and Atmospheric Administration) Climate Prediction Center said the chance of El Niño developing is quite high, with 70% chance of El Niño during the summer, and an 80% chance during the fall and winter. There is uncertainty as to how strong it may become but some models slightly favor a moderate-strength event in the fall or winter.”
The NWS added that indications were for a 73% chance of El Niño developing July-September; an 80% chance of El Niño developing September-November, and an 82% chance of El Niño developing November-January.
“The changes are very slight and slow,” said Susan Buchanan, NOAA Communications and External Affairs for the National Weather Service in Silver Spring, Maryland. “It’s not like a tornado.”
Buchanan said there was at least a chance for more rain in the Western U.S., and there may be more significant changes in other parts of the country. “El Niños can create conditions that make it more difficult for hurricanes to develop,” she said.
The next NOAA ENSO Outlook will be released on July 10. Things could change for us, but don’t count on it.