So, you want to track swell like a forecaster? Then it’s high-time you get to know LOLA, Surfline’s proprietary buoy reporting system.
Get deep enough into the surf science game and you’ll undoubtedly find buoy readings thrown out as the authoritative measure of a particular swell—combinations of numbers corresponding to wave height and period, occasionally even cardinal direction. But what are we really looking at when reading these reports? Let’s find out.
The main source of information for offshore buoy data comes from the National Data Buoy Center. NDBC collects offshore swell data and displays the dominant swell height and period. This is great for mariners, but surfers may need a bit more detail.
Developed and refined by our science and forecast teams over the last 20+ years, Surfline’s LOLA takes standard buoy data as reported by agencies such as the NDBC and applies unique formulas to that information in order to isolate and reveal the individual swells that are simultaneously influencing that particular buoy. In other words, a typical buoy reading offers only a generalized reading of conditions, meaning that it doesn’t necessarily account for secondary and tertiary swell energies—which we know can impact near-shore wave conditions significantly. This is where LOLA becomes the point of difference for tracking offshore swell activity.
As this image shows, there is often much more than meets the eye when it comes to offshore buoy readings. Image: LOLA
Let’s use a real-world example: imagine that a given buoy is showing a reading of 6.2 ft @ 8 seconds from ENE (represented by the black line in the figure above). However, what you may not realize is that this reading is actually an aggregate of multiple swells (the colored lines in the same figure). As a closer look at LOLA reveals, there is a secondary swell (3 ft @ 14 seconds from SSE) being recorded by this buoy which will undoubtedly impact the actual conditions when these swells reach the coastline. Without LOLA, that SSE swell may have flown under the radar, so to speak, meaning that you’d have shown up at the beach expecting ENE wind swell but would have been greeted instead by SSE groundswell.
OK, now to recap: knowing how to read offshore buoys will help you get a better idea of current and future conditions at a given break; understanding how to use LOLA in order to observe multiple swells at once will ensure that you have a more-complete picture of the various forces influencing conditions at a particular break.