In case you haven’t heard, it’s an El Niño year. And, according to climate scientists, it’s likely to be a strong-to-very strong one, or — as it has already colloquially been dubbed — a “Super El Niño.”
“Chances remain high for a historic event that would exceed the strength of previous El Niño events dating back to 1950,” according to an October update from the National Weather Service’s Climate Prediction Center.
So how will the North Coast be impacted? Well, that remains to be seen. Signs are pointing to a wetter and warmer winter than normal, especially on the January, February and March timeline, but those are called predictions for a reason. It is, literally, all up in the air.
Backing up a little bit, El Niño is not a particular storm but a normally occurring climate pattern that happens every two to seven years and can impact weather across the globe in different ways — some places will typically see more rain while other areas are drier. But the atmosphere is a big place and a number of factors come into play in determining what ultimately happens this year — and where.
As Warning Coordination Meteorologist Ryan Aylward at the National Weather Service Office in Eureka explains it: “El Nino is just the warm water in the tropical Pacific. It’s a half a degree above normal for five three-month consecutive periods So basically, five-months-long straight of three-month averages.”
“When that average is up half a degree above normal, it’s declared El Niño,” he continues. “When it’s really strong, like it is today — it’s like 2.5 degrees above — it’s a strong El Niño. But then what happens is all that moisture and that heat goes into the atmosphere and it causes the atmosphere to respond to that. And the end result is, typically for California, there is more moisture and there’s more heat, so you get warmer temperatures and more moisture with the cold fronts that move through — and they’re just more persistent as you go through the winter months.”
On the local front, for anyone not living on the immediate coast, Aylward has a simple message: Don’t panic but be prepared — just like you should any time the rainy season approaches.
“For inland areas, we’ve had El Niño events that have been really wet. We’ve had El Niño events that were dry, compared to normal, and even the very wet ones have not had major floods in the same way that we’ve had in other years. It doesn’t mean that we couldn’t have floods this winter. We always could. What we should plan for is just like we would any winter. Be ready for flooding if you live near a river or in a low-lying area that you would normally be concerned about flooding. And then always be watching the forecast and be ready if we do get that really bad storm.”
He emphasizes everything depends on the individual systems that come our way — as is the case every year, El Niño or no El Niño.
“It’s all about the storm, it’s not about the rainfall total for the year, it’s about the individual storms and how the atmospheric river, which is what causes the flooding for us, where it aims and where the target of the heaviest rain is and that then determines which rivers respond,” he says.
Pointing to the devastating floods of 1955 and 1964 as examples, neither of which occurred during an El Niño, Aylward says, “It’s just a matter of: Where does that atmospheric river get stuck? And every year there’s one big one that hits the West Coast.”
And he notes, El Niño years “are favored to be wetter in the second half.”
“It doesn’t mean that it couldn’t be wet in November and December, it could be. It’s just when you look at the way El Niños typically act, El Niño allows the atmosphere to produce more rain in our region in the second half of the winter than the first.”
When it comes to the potential challenges ahead, “coastal areas are different,” Aylward says.
Part of the El Niño package is what’s known as Kelvin waves, caused by warmer water below the surface coming to the surface, which travel underwater along the West Coast, leaving their mark not in crashing surf but elevated sea levels.
Here in Humboldt, Aylward says, the impacts are showing — and on top of the Kelvin waves, “thermal expansion, the temperatures being warmer in the waters, has left us elevated as well.”
“The tides are running high. They are really high. They’re 1.4 feet above the gravitational normal pull of the earth sun and moon — that normal tidal fluctuation,” he says. “So we expect that anomaly, or added heights to the tide, to continue into the winter.”
“And that’s going to be an issue, especially for places like King Salmon, when we hit the King Tides and also if we get big swells that happen to hit the coast at the same time it could cause enhanced beach erosion, more inundation of places that you wouldn’t get if it wasn’t for the waves … . So anyone with coastal interests in any way and, especially those in King Salmon, needs to be watching closely this winter.”
One doesn’t need to reach back far for a glimpse at what could possibly happen in the canal-lined enclave situated on Humboldt Bay. A combination of heavy rain, storm surge and King Tides — which reached a record-setting peak of 10.37 feet on Jan. 3 — inundated the small hamlet with waist-high water in some places over the course of three days, leaving major damage in its wake.
Now, King Tides are just around the corner again, forecast to hit during Thanksgiving week and Christmas week as well as Jan. 20 to 24. Whatever the predicted tides are, Aylward says, add on 1 foot.
“We are going to watch it and it could be high,” he says. “If it ends up being lower, great, but right now I think 8.7 is the highest tide in December, so if we add a foot to that, 9.7 is kind of our baseline is what I’m thinking we’ll be at, and then if we get a storm, we could add on top of that and it could easily end up being a foot and a half and then we’re at 10 feet.”
Around the Humboldt Bay area, Aylward adds, “Ten feet is that point where impacts increase and then 10.4, which is what we had last year, we were seeing water getting onto highways, a number of highways, so impacts increase once you get to around 10 and a half feet.”
During a recent El Niño preparation meeting with the nonprofit’s partner organizations, Humboldt Community Organizations Active in Disaster Executive Director Nick Bown-Crawford referred to last year’s event, noting the tipping point came at 10.1 feet: “We know what kind of flooding is possible in King Salmon and we know that it’s probable that it will happen again, but again these are possibilities.”
With back-to-back-to-back King Tides beginning later this month, he says HCOAD will be keeping an eye on developments and maintaining a presence “in the community and helping residents with needs as they come up.”
“The thing to kind of keep in mind here is that recovery cycle,” he says. “Recovery cycles that start overlapping with other events that start coming up can be really challenging to manage because you have relief and recovery happening at the same time. A lot of time they require the same people doing things so capacity gets stretched.”
Efforts are underway on a number of local fronts to help people gear up. That includes community meetings being hosted by the Humboldt County Sheriff’s Office and Office of Emergency Service in communities that are particularly at-risk for flooding in conjunction with HCOAD and other local and state agencies.
While the sessions with information on everything from how to properly fill and stack sandbags to signing up for county alerts and creating evacuation plans have already taken place in some areas, two more are scheduled for Ferndale on Nov. 17 at City Hall and for Big Lagoon and Orick at the Orick Community Hall on Nov. 18 from 6 to 8 p.m. Livestreams of the meetings can be watched on the Humboldt OES Facebook page at facebook.com/HumCoOES.
HCOAD is also set to hold a sandbag volunteer day with Cal Poly Humboldt in King Salmon on Nov. 14 from noon to 2 p.m. at Buhne Drive and Crab Street to help residents there and in Fields Landing protect their homes from a repeat of this year’s inundation. (Those interested can sign up at findsandbags.org or email info@humboldtcoad.org.)
Looking at the top five strength El Niños that have taken place since records on the climate pattern began being kept in 1950, only one — 1991-92— resulted in drier than normal weather for the North Coast, according to Aylward.
Along with practical preparations, like cleaning out gutters and clearing drains and culverts, he advises keeping tabs on weather forecasts and looking out for advisories, watches and warnings as winter progresses.
“In an El Niño year, the storms are more progressive so they move faster through the areas, and if they move faster through the area, then you can have wind impacts and you can get big swells but your atmospheric river doesn’t stall and it just moves right on by, so you don’t get the flood. You get rain over and over and over again. … When you have an atmospheric river that’s not moving, that’s a problem.
“And if it’s moving on through, the river comes up but it’s able to go back down,’ he continues. “So in past events in El Niño years, it’s been really wet but we didn’t really have any major flooding. So you can’t use the total rainfall for a year to make a judgement on how bad the impacts will be. That depends on the storm.”
Even in a regular year, Aylward notes, Eureka receives 9 inches of rain in an average December.
“We get a lot of rain up here, so this environment can take a lot, which is nice about northwest California,” he says “We can get a lot of rain, and build up the reservoir, and not have extremely bad impacts and it can still feel like a really wet winter. So we’ll just see how this pans out, and we’ll be ready for it.”
Kimberly Wear (she/her) is the assistant editor at the Journal. Reach her at (707) 442-1400 ext. 105 or kim@northcoastjournal.com.
This article appears in El Niño is Here.
