Researchers have announced the arrival of the elusive El Niño, but the ocean-atmospheric phenomenon is predicted to be weaker than others seen in the past.  

 NOAA's Climate Prediction Center recent updated their monthly outlook and issued an El Niño Advisory, declaring it had arrived. The event is characterized by warmer-than-average sea surface temperatures seen in the central Pacific Ocean, close to the equator. 

Since El Niño appears to be particularly weak, researchers do not predict "widespread or significant" global weather impacts. Despite these conditions, the NOAA still anticipates El Niño-related wetter-than-average weather may be seen in regions of the Northern Hemisphere, such as along the U.S. Gulf Coast. The forecasters stated that it is likely the El Niño conditions will persist throughout the summer.

"Based on the persistent observations of above-average sea surface temperatures across the western and central equatorial Pacific Ocean and consistent pattern of sea level pressure, we can now say that El Niño is here," said Mike Halpert, deputy director, NOAA's Climate Prediction Center, and ENSO forecaster. "Many climate prediction models show this weak El Niño continuing into summer."

The previous El Niño occurred between 2009 and 2010, and was classified as a "moderate to strong" event, as was the 2002 to 2003 event. The El Niño warming seen between 2005 and 2005 was classified as weak, and the 2006 to 2007 event was classified as weak to moderate. The Earth has not seen an unusually-strong El Niño since the period spanning between 1997 and 1998; this event caused heavy rainfall in the Western U.S., and hit California the hardest.

"This El Nino is likely too late and too weak to provide much relief for drought-stricken California," Halpert concluded.

The NOAA will continue to monitor the El Niño conditions and will release its next report on April 9, 2015.