As of this writing (June 13, 2014) we’re already on our third named storm of the season. Two of those (including Cristina shown above) have become major category 3 hurricanes.
Is this yet another sign that El Nino is here?
A true El Nino is actually measured along several zones along the Equator and as of early summer, it’s still in the development stages. But there seem to be many far-reaching, poorly understood aspects relating to El Nino. One of which is the warm water connection along the U.S. west coast.
What IS known: Tropical storms and hurricanes feed on warm water. When the water is warmer, those types of systems have more energy to work with, hence a more active season.
And that bring us to the two great west coast hurricane myths:
1) Hurricanes off the coast of Baja “push” more of that warm water up the coast.
2) California never gets hurricanes.
Myth #1: These storms don’t really push water around outside of the immediate vicinity of the storm, something referred to as storm surge which is a major concern of landfalling hurricanes.
Sure, the larger storms generate swells that sometimes make it as far as Southern California, especially if there is no opposing swell from the north or northwest. But that transfer of wind energy to the water doesn’t result in a current of warm water to start flowing uphill.
For a little outside perspective on the subject, I consulted my friend and colleague Max Mayfield, former director of the National Hurricane Center.
“I think you are on the right track in that the hurricanes would have to be pretty close to California for any significant storm surge impact,” said Mayfield, referring to that near shore “push” of water created by a hurricane.
“I can guarantee the 1858 hurricane that hit San Diego would have had storm surge.”
Wait. A hurricane hit San Diego? That brings us to myth #2.
The 1858 hurricane to which Mayfield refers is a somewhat recent discovery (via historical records) of the only hurricane known to have made landfall in California. It’s also believed the storm formed during an El Nino year. However, records are sparse and news accounts were few and far between. They didn’t have the internet back in 1858.
San Diego, 1872 (courtesy San Diego History Center)
Researchers Chris Landsea and Michael Chenoweth estimated that if this hurricane were to strike San Diego in modern times, $500 million in damage would result. At the time of the hurricane, San Diego was only a small settlement with a population of 4,325. Today the population of San Diego County is over 3 million.
In recent times, we have had some close calls with tropical weather. Most notably, in 1997 when we had a significant El Nino in progress:
“Hurricane Linda of 1997, during a strong El Niño event was forecast by the National Hurricane Center for a couple of advisories to make landfall near San Diego as a minimal hurricane or strong tropical storm (Lawrence 1999). Fortunately, this storm weakened and turned back to the open Pacific Ocean without impacting land.”
Regarding the power of storm surge, Mayfield continues: “Sandy had a storm surge that pushed over 100 n mi up the Hudson River from New York Harbor, and Isaac (as a slow moving Cat 1) forced the Mississippi River to flow backwards for almost 24 hours and pushed a storm surge more than 300 miles upriver.”
So, in order for a hurricane to PUSH warm water into southern California and northern Baja waters, it would have to be pretty close.
Yes, they can get close to home, with the best chance of that happening when the water is unusually warm, such as during a moderate to strong El Nino.
This season could get interesting...
Hurricane season in the eastern Pacific runs from May 15 through November 30th.