El Niño Is Here: What a Strengthening 2026-27 Winter Could Mean for Boulder Creek

Ask anyone who's wintered up here and they'll tell you how it goes: the San Lorenzo comes up, a tree comes down across Highway 9, the power blinks out for a day or two, some years worse than others. So when word gets around that a strong El Niño is on the way this winter, it's worth knowing what that does and doesn't tell us. The word-of-mouth part checks out: NOAA's Climate Prediction Center has an El Niño Advisory in effect and gives it high odds of strengthening into a big event. What that means for Boulder Creek specifically is the murkier question. A strong El Niño tilts the odds toward a wetter winter across California, but the signal is strongest in Southern California and much shakier up here in the Santa Cruz Mountains. So the move isn't to panic, and it isn't to bank on a soaking. It's to get storm-ready now, because our winters bring floods, outages, and road trouble in plenty of years, El Niño or not.

What NOAA is forecasting

Per the Climate Prediction Center's discussion issued July 9, 2026, El Niño conditions are present now, there's about a 97 percent chance they persist through early spring 2027, and there's roughly an 81 percent chance of a very strong El Niño during October through December, an event that would rank among the largest on record since 1950. El Niño is a natural warming of the tropical Pacific that shifts weather patterns worldwide; a strong one tends to nudge the winter storm track in ways that raise the odds of wet weather across the southern United States.

Two caveats worth holding onto. First, this is a forecast, and forecasts change; the CPC updates it monthly. Second, El Niño describes odds, not certainty, and it says more about the season as a whole than about any single storm or date.

What a strong El Niño could, and couldn't, mean here

This is the part that gets oversold. El Niño's clearest, most reliable effect in California is on Southern California, where strong events genuinely raise the chance of a wet winter. For the Bay Area and Santa Cruz Mountains, the connection is real but weaker and less consistent. Strong El Niño winters here have run the gamut from very wet to fairly ordinary. So no one, us included, can tell you this winter will be a big one for Boulder Creek.

What we can say is that a stronger, more active storm track raises the odds of the kinds of winters our terrain handles badly: saturated ground, swollen creeks and the San Lorenzo River, power outages, fallen trees and limbs across roads, and stretches where Highway 9 is the weak link in and out of the valley. Those risks show up in ordinary winters too. A strong El Niño just makes it a worse year to be caught unready.

What to do now, while it's dry and calm

Spread the work across the fall instead of scrambling when the first big system shows up. Start here:

• Prepare for outages before you need to. Water, lights, a way to charge phones, and a plan for anyone who depends on power. See our power-outage preparation guide.
• Get your winter-storm basics in order. Supplies, defensible drainage, an evacuation-ready mindset. See the winter storm checklist.
• Know your roads. Understand how Highway 9 and mountain roads behave in storms, and where to check conditions.
• Sign up for alerts now. Register for PG&E outage alerts and county emergency notifications before the season, not during a storm.

We'll be publishing more focused fall and winter guides, on getting your culverts and drainage ready, understanding atmospheric rivers, and where to find sandbags and closures, and linking them here as they go up.

How to watch it through the fall

Don't chase every headline. A few trustworthy sources beat a stack of scary ones:

• NOAA Climate Prediction Center, the monthly ENSO update
• National Weather Service, Bay Area, local forecasts, watches, and warnings
• PG&E outages and safety, outage map and alert sign-up
• Our Mountain Status page, which pulls the live local sources together

Frequently asked questions

Is a strong El Niño really coming this winter?

NOAA's Climate Prediction Center has an El Niño Advisory in effect, with about a 97 percent chance it lasts through early spring 2027 and roughly an 81 percent chance of a very strong event in October through December. It's a forecast, and it updates monthly.

Does that mean Boulder Creek will have a wet, stormy winter?

Not necessarily. El Niño's strongest California signal is in the south; for the Santa Cruz Mountains the connection is weaker and less consistent. It raises the odds of an active winter but doesn't guarantee one. Prepare either way.

What should I do to get ready?

Spread the prep across the fall: get ready for power outages, work through the winter storm checklist, understand mountain roads in storms, and sign up for PG&E and county alerts now.

Where should I watch for updates?

The NOAA Climate Prediction Center for the seasonal outlook and the National Weather Service for actual forecasts. For live local conditions, use Mountain Status.

This page reflects the NOAA forecast as of the reviewed date and is not a substitute for official forecasts and alerts. For live conditions, see Mountain Status. In an emergency, call 911. Last reviewed: 2026-07-20.