It is highly doubtful anyone will be shocked to learn that it is going to get pretty damn big in the Western Atlantic over the coming week. With the biggest winter swell of the past few years lining up, it’d be foolish to think of this as an under-the-radar swell, but where the best surf will be found could end up being somewhere off the well-trodden paths. For many surfers, in many regions, it will be a wait for the size to come down and the conditions to improve before they can enjoy their share of the swell. For others, this will be the swell they have been waiting all season, or even waiting many years to arrive and turn on that one special break.

LOLA animation of the storm over the Western Atlantic that will send large swell to the East Coast and Caribbean.

When we start to see modeled swell heights of 15ft at 15secs along the US East Coast that are at least in the realm of reality, even our most salt-encrusted forecasters start to raise an eyebrow. This leads to thoughts of past swells, both forecasted and surfed, which evolves into group discussions that are mixed with equal parts scientific analysis and story time. During these chats, two winter storms from the past decade kept surfacing, one from March 2008 and one from February 2015 — but let’s look at our bright future, before remembering our glorious past.

Low pressure moves off the Mid Atlantic coast into Friday morning, intensifying off the Northeast and persisting as strong storm through the weekend as it slowly tracks to the southeast (see animation above). Current model guidance drops the low to 969mb, developing winds of 50-60kts. There are some differences between major models on the storm’s exact location over the weekend, and when it will weaken and exit the Western Atlantic next week, but there are no quarrels on the fact that a significant and large, multi-day swell will impact the East Coast and the Caribbean over the days ahead. With no lack of sizable surf on tap, conditions will be the concern for most areas, at least through the first half of the swell as the large storm extends its influence (meaning winds) down the Eastern Seaboard and even into the Western Caribbean.

To get an idea of what might lie ahead, we pulled the buoy measurements at select stations off the Northeast US, Virginia/Outer Banks, Florida, and Puerto Rico that had archived data for the storms back in March 2008 and February 2015. We then compared the latest model forecast swell heights at those stations to the actual readings from past storms. And as you can see above, the upcoming swell has the potential to surpass both of the previous memorable and large swells.

St. Patrick’s Day Swell March 2008

The St. Patrick’s Day swell of 2008 began as low pressure moved off North Carolina, rapidly intensifying as it lifted Northeast before merging with another strong storm to the south of Newfoundland. The storm developed hurricane force winds and bottomed out at 965mb, developing seas around 40ft. Virginia Beach and the Outer Banks were the standouts on the East Coast while the storm lingered further north off the Canadian Maritimes, delivering the most memorable portion of the swell to the Caribbean. More specifically the Western Caribbean where it was, and still is, considered one of the biggest swells on memory to hit the northwest corner of Puerto Rico. Peak buoy reading from the select stations was off Puerto Rico at 16ft at 17secs. For a flashback of the swell, and the way the internet used to run, check the Swell that Ate the Atlantic Parts One, Two, and Three.

Pre-Valentine’s Swell February 2015

2015’s pre-Valentine’s Day swell began as low pressure developed off Southeast US coast and strengthened off North Carolina before tracking northeast into North Atlantic. The 966mb low produced satellite observed, 40-50kt+ winds offshore of the Mid Atlantic coast. Peak buoy reading from the select stations was off Virginia Beach at 16ft at 15secs. The Mid Atlantic, Florida (which received all day offshores from a trailing cold front), and much of the Caribbean were the standout locales. See the evidence in, The Purple Blob That Ate the Atlantic.

The Verdict? The Jury’s Still Out

Current modeled swell heights for the upcoming swell are above the readings measured during the previous two comparable storms. The three biggest differences between the coming storm and those prior are, 1) the initial set up closer to the coast, 2) the slow movement and, 3) the size of the upcoming storm and the impact it will have on conditions. The slow-moving storm will result in a longer duration swell and its track will ensure that all on the East Coast will see sizeable surf. It is conceivable that many areas will see overhead surf into the middle of next week. But while the slow movement will keep solid swell in water longer, it also means conditions will be slower to change. And with the large storm influencing winds all along the East Coast and down into the Caribbean, that won’t be a good trait of this storm for many areas.

For the final verdict, we’ll have to see how it all plays out over the next week to find out if the buoys match the models and come in bigger than the previous swells registered. And we’ll have to see how the conditions play out to know if the extra days of swell are a benefit or if they just add agony while waiting for that one clean day or session. To find out those answers, be sure to follow your Regional Forecast for the latest thinking on when and where in your area will see the best conditions during the large ,and long, run of swell ahead.