Brian Garcia, Warning Coordinator Meteorologist with the National Weather Service for the San Francisco and Monterey Bay region, said forecasters are keeping a close eye on El Niño—the periodic warming of the Pacific Ocean that is often associated with wetter than normal weather in California.
While not every wet winter is a result of El Niño — last year’s storms took place in a so-called “La Niña” pattern, which is the opposite of El Niño — Garcia said in an interview that this year’s pattern is particularly intense.
This interview has been condensed for clarity.
KAZU: In basic terms, what is El Niño and how does it impact weather?
Brian Garcia: In short, El Niño is the sloshing of the warm and cold waters across the equatorial Pacific. This year we’ve got warm waters pretty much across the entire equatorial Pacific, and that is El Niño.
KAZU: And that doesn't necessarily mean a wetter winter, right? El Niños are not necessarily all created equal.
Brian Garcia: Correct. Just because we have an El Niño, it doesn't mean that we're going to end up like the 1982-1983 winter, or the 1997-1998 winters where we had exceptional amounts of rainfall. We could end up with something like the 2015-2016 winter where we were below 100% of normal rainfall, but we had a very strong El Niño.
KAZU: So, essentially, an El Niño pattern just increases the odds that we might have a wetter than normal water year. Correct?
Brian Garcia: Correct. That's exactly right.
KAZU: And there are other things to look at. We're looking at things like king tides and coastal erosion and things like that, that will also potentially be a hazard this winter. What are we seeing?
Brian Garcia: Yeah, you know, with a generalized El Niño pattern, it actually ends up being a really fascinating type of event. We might actually see some pretty significant swell activity this winter. And it's something we really have to watch out for. So, as we get towards the holidays, Christmastime and New Year's and into Martin Luther King Jr. Day, those times of year are the times we start to get the king tides. So now we have the highest astronomical tides of the year, and we have large swell. So, we have a lot of waves set up and we can get some pretty impactful storms battering our coast.
KAZU: We had so many consecutive years of drought in California, and now it looks like we may have a couple of wet winters. Does this tell us anything about the longer term trends, or do we just need to look at each season individually?
Brian Garcia: Good question. So, the long-term trends for California, it's always been a boom or bust state. We have always seen droughts and we have always seen periods of significant precipitation. The thing that's really kind of changing now is the intensity of these events. So how deep of a drought do we go into? How much rain do we get in any given winter? So, the phrase "weather whiplash" that was coined several years ago comes to mind with this. We're going to start to see bigger swings in our normals.
KAZU: So, as we head into another winter, what are some things that people should be doing to prepare?
Brian Garcia: Same thing that we do every winter. Even in drought winters, we encourage people to prepare for a wet storm, because really all it takes is one whopper of a storm to cause significant issues for people and their livelihoods and their safety. But yeah, it's time to prepare. It's time to winterize. This is a good wake-up call and a reminder that winter is here, the wet season is upon us and we need to make sure that we're prepared, from windshield wipers and tires to sealing of doors and windows.
Garcia said now is also a good time — if you haven’t done so already — to make sure you are signed up for emergency notifications from your county. Wherever you live, it’s as easy as a couple of clicks at alertthebay.org.
