Climate experts highlight warmer than usual ocean temperatures and potential El Niño event
SAN DIEGO, Calif. (KESQ) – Record high temperatures across Southern California were an anomaly throughout March.
According to climate researchers, the same atmospheric anomalies that drove the historic heat wave have also been driving trends in the oceans off the California coast.
Record high sea surface temperatures have been measured at the Scripps Pier in San Diego in recent weeks and months.
There are several factors that have led to the record heat in the ocean, some of which are tied to the heat wave we experienced in Southern California for most of March. That heat wave was driven by a moderate high pressure system that stayed situated along the California coast for over a month.
That high pressure did several things to regional weather patterns. Dr. Art Miller, Research Oceanographer Emeritus with the University of California, San Diego's Scripps Institution of Oceanography, said while he has not confirmed it, the pattern very likely led to fewer clouds over the Pacific. Fewer clouds would mean more heating from the Sun on the surface of the water. The presence of abnormally warm air, too, would have directly warmed the surface. He also said a lack of evaporative cooling from winds blowing over the surface of the ocean allowed temperatures to be driven up.
Northerly winds are also often responsible for an ocean process called "upwelling." That process allows cooler water to rise to the ocean's surface, which typically balances out temperature anomalies. Dr. Miller pointed to that process essentially being "shut down," which further limited the cooling of the surface.
"Those three things together, combined with the reduction of upwelling winds very likely led to this large scale sea surface temperature anomaly," the researcher explained.
Dr. Miller also explained what we're seeing now looks like a common precursor to El Niño patterns, which are often associated with above average rainfall for our region. A stretch of warmer-than-usual water on the surface extends from the California and Baja California coasts all the way to the Equator and International Date Line. That's referred to as the "Pacific Meridional Mode" (PMM), a pattern that is often a precursor to El Niño.
Subsurface heat in the tropical Pacific is also continuing to build, which is also a big sign for climate experts.
"Right now, the the gun of El Nino is loaded in the tropical Pacific," said Dr. Miller.
Experts said El Niño events aren't always the best predictors for wet weather, but did say the west coast typically sees above average rainfall compared to La Niña or neutral weather conditions.
"It's really hard to predict past April from the initial conditions in the winter what's going to happen next year. But right now, everything is poised for an El Nino event to develop over the summer and really intensify into the winter," he explained.
While substantial rainfall remains uncertain, local agencies said they remain prepared to respond to natural disasters.
Palm Springs Fire Department Captain Ronald Skyberg walked through the Araby Wash today, pointing out how just a couple of inches of rainfall in the mountains drain through and can cause water to spill out of the wash.
When an El Niño pattern materializes, he said the department often commits to extra preparation, including scouting and pre-planning for potential water rescues.
"We're not for sure if it's going to hit this year or not, but if it does right, we want the public to know and everybody else to know that we are always prepared to respond to any type of emergency," Captain Skyberg assured.
