Friday morning’s thunderstorms doused the coast with nearly a half inch of rain.
Even before the storm, the region’s rainfall totals for this water year were about an inch above average according to the National Weather Service.
Scientists from Scripps Institution of Oceanography and the National Oceanic and Atmospheric Administration identified heavy rainfall as just one of the factors making this year’s El Niño super.
They shared new insights on record breaking conditions influencing this year’s abnormalities on Thursday, including higher ocean temperatures and sea levels.
“We're now sitting on the precipice of yet another Godzilla El Niño, where temperatures are supposed to be and are already higher than we've ever measured in the past,” said Jennifer Smith, a marine ecologist with Scripps.
California’s coast was already experiencing higher water temperatures before El Niño conditions arrived. But the scientists noted a surge of warm water from the east is amplifying a marine heat wave.
Smith recorded the highest temperatures seen in November off Scripps’ pier.
“We're still measuring over 75 degrees right here in our backyard,” she said. “Yesterday [Wednesday] was yet another record breaking day for warm water off our coast.”
These warmer temperatures are also being measured in deeper waters. Scientists saw temperatures in the high seventies as deep as 50 meters.
“This is quite unprecedented,” said NOAA’s Andrew Lising. “We're looking at some of the warmest temperatures in the deep waters that we've ever had in this record of 20 years now of sampling.”
Normally, east trade winds push these warmer waters toward Australia. But during an El Niño those winds die down.
“And when that happens all that warm water that was pulled up toward Australia there it all sloshes back toward South America,” Lising said.
The phenomenon is known as a Kelvin wave. This sloshing is bringing higher tides to San Diego.
Mark Merrifield is a physical oceanographer at Scripps. He attributes record breaking sea levels to the combination of Kelvin waves, bigger swells and warmer waters.
“Typically with an El Niño in San Diego, you might get a half a foot, to maybe a foot, but we're well above that with this El Niño event,” he said.
The current sea level is more than a foot higher than what is expected in El Niño conditions, he said. This weekend eight foot swells are expected to crash onto the county’s beaches.
Imperial Beach will likely be impacted, according to Merrifield.
“The strong wave event on top of this foot and a half sea level anomaly is going to push well above what we consider minor thresholds flooding … in Imperial Beach getting up to moderate to severe conditions,” he said.
Other low lying areas like bays and estuaries may also flood. The National Weather Service is forecasting rain on and off through Wednesday.
