How to read a surf forecast

How to read a surf forecast

Surf forecast terms

First off – let’s cover the basics. Think of this as your Bachelor in Understanding The Surf Forecast degree. For your degree, these four variables are the basics: swell, swell height, swell period and swell direction. Understand this holy foursome and you will have a decent package of know-how and you are ready to start planning your next surf session.

Swell

Waves are always the result of mechanical action – for example, the impact of the wind or a boat.

If we don’t feel the wind but see the waves, it doesn’t mean that they are formed on their own, but most likely are the result of the storm, raging somewhere far from here.

If you put your finger into the water, you will create circles, waves. This happens because we acted on the water mechanically. Wind affects water in the same way – mechanically.

Waves are formed because of the blowing wind, and then they roll over the entire surface. That is why we can see waves in a completely calm places. The set of unrest on the surface of the water formed by the “far away” wind is called a swell.

Swell is a collection of waves generated by specific conditions like a storm. Swell can travel a long way to the beach (think like 2000 miles offshore). The swell height, period, direction are the ones that determine how surfable is the swell. 

Swell Height

The swell height is measured from the base of the wave to the top of the wave. Note: swell height does not always mean the height of the wave as it is an estimated average height of the highest one-third of the swells. Generally, this parameter gives you a picture of the average height of the possible waves. 

Swell Period

An extremely crucial part of surf forecast – also known as a swell frequency. Measured often from one peak to another peak. Correlates in how much energy there is in a swell. A thumb rule: the longer the period the more energy in waves. 

Swell Direction

The direction from which the swell is coming. A thumb rule: the more directed the swell is when hitting your local beach the stronger the waves. Look for islands that might block the incoming swell.

Swell energy

Indicates the power of the predicted waves and can be the most useful guide to how powerful the surf is likely to be. It is a combination of both wave size and period.

Photo source: unsplash.com

Wind Direction

The quality of the waves depends on the wind on the coast. 

If the wind blows from the shore towards the water - this is an offshore. Such a wind maintains waves from collapse and makes them sharper.

The wind blowing towards the shore is an onshore. Onshore blows off the peaks and causes the waves closure ahead of time. It is the most unwelcomed wind for surfers.

The wind blowing along the shore is a cross-shore. In this case, everything depends on the force and direction of the wind. Such a wind can either slightly spoil the waves or ruin your vacation.

Photo source: unsplash.com

Wind Gust

Gust is a sudden increase in the wind's speed that lasts no more than 20 seconds. With strong wind gust, it can change the surfing conditions rapidly. A good thump rule: 9mph gusting to 18mph will make surfing conditions messy. 

Tide 

At low tide the water level drops to its lowest and flows from the coast. During high tide the water flows to the coast.

This really depends on the spot and you should always ask the locals about the best timing to get out in the water. Most often it’s when the tide is moving either “low going high” or the tide is on the rise.

Usually, at low tide reefs and stones are exposed.

 

How to read  surf forecast in Windy.app

Windy.app provides Surf forecasts for surf spots all over the world. To see the Surf forecast, open any spot in our app and tap "SURF".

Final remarks - extra curriculum 

The modern weather forecast is scientifically as accurate as possible but as anyone who has been in the water and witnessed the ever-changing nature of Mother Nature (sometimes you can go in an hour from great surf into abysmal) – make sure you have this covered:

+ Don't forget to select SURF setting from the Windy.app selection to get the essential information for surf forecast.
+ See if there are live stream cameras available at the spot - check the current forecast and see how it looks like in reality.
+ Ask the locals in the Windy.app local chats how are the surfing conditions.

In the end, with surf forecast the same thing applies as with surfing itself – the more time you spend at your local surf spot, the better you become.

Read more:

How to choose the right wetsuit

How to choose a surf school? Guide on surf schools for beginners, intermediate and PRO

Surfing in Europe: best spots and destinations

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