Once upon a surf forecast—the ultimate surf bedtime story

Still confused by surf forecasts? You’re not the only one. My friend Gavin, who writes Go Surfing San Diego and the Sunday Stoke surf forecast newsletter, wrote a blog about how to read surf forecasts after our recent chat on the pod. But I’ve decided we can do better. We can explain the surf forecast like we’re explaining it to a five-year-old. Are you ready for a surf forecast bedtime story, kiddo?

Prefer to listen instead of read? This story comes straight from The Wipeout Weekly podcast—yep, that’s my real voice, not a robot.

What is Surfline?

Do you love the ocean and want to know when it’s a good day to go surfing? Surfline is like a magic weather app—but for waves! It tells surfers what the ocean is going to do. But sometimes it uses big words, so let’s make it super simple. And it also put all the cams behind thepaywall, so some of your little surfer friends don’t like it much.

Wave Height = How big the splash is

Let’s talk about wave height—that’s how big the splash is. Surfline tells you how tall the waves are. If it says 1 to 3 feet, that means the waves are small and fun—perfect if you’re just learning. If it says 5 to 6 feet, WHOA! That’s big and might be too scary unless you’re a surf superhero. Bigger waves = more whooshing and crashing.

Sometimes you’ll see two different wave heights. One will have “observed” in brackets next to it. This means that some dude—because it’s usually a dude—went to the beach, looked at the waves, took a measuring tape out, and reported the wave height back to headquarters. Actually, Harry, we don’t know how they know for sure. But hey, they’re experienced surfer dudes.

Swell direction = where the waves come from

Next to the wave height, you’ll spot “swell direction.” That’s where the waves come from. Waves travel across the ocean like they’re going on vacation. Surfline tells you which way they’re coming from. If waves come from the South, they’re summer visitors! If waves come from the North, they’re winter visitors!

Depending on where you’re standing on the beach, some waves might come straight at you and be great for surfing, while others might sneak past and go somewhere else.

But Mom, there are these two swells, one primary and one secondary. Yes, son, a beach can experience two different swells at once, coming from two different directions. The primary swell is stronger than the secondary swell. It’s from Latin, baby—primarius, which means of the first rank or principal.

️ Different beaches like different directions

And most importantly, different beaches like different directions. You know, like you and Tony like different flavors of Kiki Milk. Beaches facing South like swells that travel from magical Hawaii. Beaches facing North prefer swells from Alaska. It’s mostly cold there.

Wind: the invisible hand

Oooooh. It’s getting windy here! Wind can help waves be nice and smooth… or make them messy! And that’s another thing you see on these Surfline charts.

Offshore wind blows from the land toward the ocean—it helps waves stand up tall and pretty. Onshore wind blows from the ocean to the land—it makes waves fall down and get messy. No wind is like no hands on your toy—just how you left it. Nice and calm!

If the wind is gentle (like blowing out birthday candles), that’s good. If it’s too strong, it makes the ocean bumpy like a trampoline. Knots? What about knots? Oh, it’s a measure sailors use. All you need to know is that if you see that a wind speed is under 5 knots, let’s go surfing. More than 5 knots, it will be a wee bit messy. And over 10 knots, we’re staying home.

⚡ Wave energy = power boost!

Mom. What’s wave energy—is this going to be on a test? Kilo Julies? No, Harry, kilo joules, it’s how we measure energy. Kinda like calories, but a bit different. Waves are water with power inside. That power is called energy. Surfers love it because it helps them ride! That energy is what pushes a surfer on their surfboard. When the wave comes, it gives the surfer a little shove and says, “Wheee! Let’s go!”

What if Surfline is too confusing?

If Surfline feels too hard, don’t worry! You can always: ask a grown-up surfer to help, call your local beach lifeguards (some have surf reports!) or you can use Daddy’s computer and copy and paste a Surfline’s analysis into ChatGPT and ask it to explain it to you.

And that’s it! You now know the three big things: how tall the waves are, where they’re coming from, and if the wind is being nice. You’re basically a surf wizard now, Harry. Now go pretend your bath is Pipeline.

I think it’s clear from this post that I do not have kids.