It's been a funny old year, 2021. Travel, no travel. Restrictions, no restrictions. But despite the yo-yoing of getting around, one thing's remained the same; there were still waves. And here at MSW HQ, we still covered everything we could -- and then some. And right here, we've narrowed down a list of the sessions that helped shape the past 12 months.
Massive Maverick’s and Peter Mel's Mind-Boggling Ride
Want to know how long this year's been? Peter Mel's insane-o wave was almost a year ago. On Sunday January 8, a giant, long-period swell hit Maverick's, with perfect local conditions in light variable winds.
The low that produced the swell started off as a weak feature off Japan on Tuesday 5th January. At this time, there was also a giant, complex area of low pressure filling up the northeast Pacific. The developing low initially drifted eastwards and deepened only slowly over the first 36 hours or so.
But when it reached about half way across, it got sucked into the flow south of the mother system, and deepened explosively. It tracked east through Friday 8th, generating a humungous pulse of westerly swell from the storm-force winds on its southern flank. On Saturday 9th, the storm veered northeast around the periphery of a large area of high pressure that was stationed off the coast of California.
The swell was exceptional at Maverick's for several reasons:
*The fact that the low developed on the eastern side of the Pacific rather than on the western side, meant that the swell hit the coast more directly, less spread-out, and hence bigger.
*The windfield on the southern flank of the low was quite small, but the movement of the storm created a much longer ‘virtual’ windfield (dynamic fetch, see my article here), which greatly enhanced the size of the swell.
*At Maverick's there is an intense focusing effect, which increases the local wave height and really comes into its own with long periods. At the time the swell peaked, the peak period was about 19 secs, which contributed to the breaking wave height being more than twice the offshore wave height.
*The swell initially arrived on top of a previous dying swell from the last few days, but this practically disappeared by mid- afternoon, leaving the main swell untouched.
The Biggest Jaws Swell in Years
On Tuesday January 12, a low started to form off Japan and move out into the open North Pacific towards the northeast. It deepened rapidly as it tracked across the western half of the North Pacific, before veering northeast and weakening. A large swell was generated by the storm-force winds on its southern flank, the bulk of which travelled towards the east and passed north of Hawaii. However, the swell also spread out towards the southeast, reaching Hawaii on 16th.
In contrast to a previous system that deepened on the eastern side of the North Pacific (see Maverick's swell, above), this system deepened on the western side and peaked before it got half way across. This storm, like the Mav’s one, also moved in the same direction as the swell it was producing (dynamic fetch), which contributed to the swell being so large.
See the full feature HERE
A huge, long-period swell hit Hawaii on 16th, persisted through 17th but dropped quite quickly after that, since most of the swell passed to the north. At Peahi, breaking wave heights were over 30 feet, and, although the swell itself was super clean and lined-up, it was hampered by a local easterly wind, making the faces bumpy. The wind was due to the pressure gradient between a large area of high pressure centred west of California and an area of relatively low pressure southwest of Hawaii.
On 17th, the swell was down to 20 feet or so at Peahi, and steadily dropping throughout the day. The pressure gradient producing those easterly trades had weakened, resulting in light variable winds or light easterlies, and much cleaner wave faces.
Indonesia Goes Kaboom
On July 14, a large, long-period swell arrived in Indonesia, with wave heights hitting ten feet or more and periods holding at around 16 secs.
The reason why this swell was so special was that it was generated by a low pressure system that deepened further to the east than normal, closer to Indonesia, but still far enough away for local conditions to be good.
Full story, HERE.
The initial disturbance was on the periphery of a large low in the far south of the Indian Ocean near the Kerguelen Islands, that began to form around 9th July. This quickly developed and moved northeast, with high pressure pushing up behind it, maintaining an area of storm-force winds from a southerly quarter. The moving windfield and the fact that the storm still persisted as it approached Western Australia around 11th, meant that the swell held its size as it propagated towards Indonesia.
The swell first arrived at the most exposed central areas such as West Java on 13th, and then went on to areas further west and east. At Uluwatu, for example, wave heights ramped up during the morning of 14th, then held steady at around eight to ten feet all afternoon and through most of the next day, before ramping down during 15th and 16th.
The Terror Swell -- Teahupoo
August Friday 13, a massive swell hit Tahiti, with wave heights at Teahupoo over 15 feet and periods of around 18 secs. It was still massive on Saturday 14th, before dropping steadily over the following days.
The swell was generated by a low pressure system that deepened east of New Zealand on 9th August, then further intensified and expanded as it shifted east. By 11th August, a massive area of storm-force south-southwest winds had developed almost directly south of Tahiti, with open-ocean wave heights of over 30 feet over a large area. This generated a really solid pulse of swell with periods of up to 20 secs, heading directly for Tahiti.
Relive the carnage HERE
The swell arrived overnight on 12-13th and increased through 13th. The peak of the swell at Teahupoo coincided more or less with the optimum combination of offshore wave heights of over 12 feet and periods of around 17 or 18 secs. It dropped a notch overnight but still continued to pump through Saturday 14th, with periods holding around 15-16 secs and wave heights at Teahupoo still hitting 15 feet or more.
Local wind conditions were challenging at first, with moderate to fresh northerlies (offshore) on Friday 13th, due to a frontal system that passed south of the islands; but became much lighter over the next two days.
Hurricane Larry Lays Up Atlantic Season
Larry, the twelfth named storm in the 2021 Atlantic hurricane season, started off as a tropical wave depression that moved off the coast of West Africa around 29th August. It quickly intensified, becoming a tropical depression on 31st August, a tropical storm on 1st September and a hurricane by 2nd September, reaching Category-3 on the Saffir-Simpson Scale. Over the next few days it tracked westwards, gradually arcing around to the west-northwest and expanding into a large system covering a wide area.
Around Friday 10th September it turned towards the northeast and accelerated, crossing Newfoundland on Saturday 11th and then moving out into the open Atlantic as a post-tropical storm. Later that weekend, it continued to track towards the northeast and merged with a mid-latitude depression that spawned out of the Labrador Sea, forming a larger system that deepened southeast of Cape Farewell.
Chasing Larry, HERE
The westerly movement of the storm between 4th and 9th September, combined with the unusually large area of hurricane-force winds on its northern flank generated a pulse of large, long-period swell that produced several days of good surf on the East Coast of the U.S. and Canada. The storm itself arced around to the northeast a considerable distance from the coast, so it didn’t directly affect local conditions.
Larry also generated two distinct pulses of swell for the southwest UK and the west coasts of Europe.
Around 10th September, while it was just south of Newfoundland, Larry was still a Category-1 hurricane, with a large area of hurricane-force winds on its southern flank. This spat out a pulse of swell that spread out across the Atlantic, hitting westerly exposures on Monday 13th with unusually long periods of well over 20 secs. For the UK and Ireland to receive a swell from a system that still retains most of the characteristics of a tropical storm, is very unusual.
The second pulse of swell was generated by the result of Larry combining with that new low. It arrived on 14th and 15th and was much more typical of autumn and winter swells in the North Atlantic. The windfield was much larger in area than the first one, although it didn’t contain such strong winds. It was directly in line with areas in the far northwest such as northwest Ireland and western Scotland, which received quite large wave heights, but it was hidden behind Ireland for the southwest of the UK, which received smaller surf.
Hurricane Sam Boomerangs Everywhere
On 7th October a super long-period swell arrived at westerly exposures in Europe, with wave heights over six feet in many places and some excellent conditions in the southwest of the UK. The swell was generated by Hurricane Sam after it transitioned to a post-tropical storm way over on the other side of the Atlantic.
Sam originated from a disturbance that moved off the coast of Africa around 19th September. It travelled west, passing south of Cabo Verde and became a tropical storm on 22nd September, then became a hurricane on 24th as it gradually arced towards the WNW. On 25th it hit Category 4 on the Saffir Simpson scale, and almost reached Category 5 (the highest) by 26th, with sustained winds of 155 mph, while about 800 miles east of the Leeward Islands. It then turned towards the north, persisting for about four days as a major hurricane, although relatively small in area. Around 2nd October it started travelling over colder surface waters and started weakening as it travelled towards the northeast, out into the open North Atlantic.
Sam Gallery, HERE
On 5th October it became entrained into a developing mid-latitude low, just east of Newfoundland, quickly expanding a large binary system that revolved around itself for about 18 hours. A large area of very strong winds on its southern flank generated a long-period swell that propagated towards Europe.
Sam generated some clean swell on the west side of the Atlantic. The Lesser Antilles, the Windward Islands, the U.S. and Canadian east coasts, all got good pulses of swell as the system made a large arc staying at least 800 miles from the coast. Then, when it expanded into that binary system, it sent an epic, long-period swell to westerly exposures in Europe, the first super long period forerunners of which began to arrive late Wednesday 6th October.
Europe Gets a November Banger, Nazare Steals the Show
Between 12th and 15th November a couple of epic long-period swells reached Europe, with periods of up to 19 secs and wave heights reaching 15 feet in places.
The swells originated from two low pressure systems that originated off the eastern seaboard of North America around the 8th and 9th November. The two storms started off relatively close to each other, then accelerated out in a north-easterly direction, one behind the other, as they expanded and intensified.
The first system deepened north of the Azores and continued to track northeast, passing over Scotland on 12th November before quickly dissipating in the North Sea. An area of storm-force winds on its southern flank generated a large swell and some windy conditions for northern areas on 12th and some cleaner swell in the south on 12th and 13th.
The second system was hard on its heels, deepening explosively northwest of the Azores on 13th, with a larger and more powerful windfield than the first one. Instead of blasting into Ireland and Scotland it arced around to the north, towards Iceland. As a result, in hardly encroached on local areas, helped by a ridge of high pressure that pushed up from the south. It generated a pulse of high-quality long-period swell that reached most areas on 14th and persisted through 15th and beyond.
Around the beginning of December, the North Atlantic switched to a much more active pattern, after a couple of weeks of being hampered by a large blocking anticyclone. This ‘flipping’ from one state to another is quite normal behaviour and is a classic example of the North Atlantic Oscillation (see my article here). As a result, a train of low pressures generated some great swell for the UK and Ireland during the middle of December.
Around the 7th and 8th, a large, tight area of low pressure deepened west of Ireland and generated a huge, short-lived pulse of swell and some ragged local conditions. While this swell was fading away, two more lows were forming. The first began to spawn near Greenland around 8th, and then tracked across the northern half of the North Atlantic, intensifying at the same time. The dynamic fetch on its southern flank generated a pulse of long-period pulse swell that arrived around 10th.
The second system appeared near Nova Scotia on 9th and quickly tracked northeast, expanding and intensifying. It then got sucked into the westerly flow to the south of that first system. By 11th it had expanded into a huge low pressure southwest of Iceland, with a massive area of storm-force winds on its southern flank generating open-ocean wave heights of over 40 feet. A huge swell hit northwest Ireland on 12th, and a smaller, long-period swell hit in Cornwall between 12th and 14th.
Over the following days, high pressure began to expand from the Azores towards the northeast, extending over Britain and Ireland. At the same time, another two lows developed on the far side of the Atlantic. Both systems started off just northeast of Newfoundland and tracked towards Iceland, and both contained a moving area of strong winds, which generated swell.
The main bulk of the swell from both of these systems travelled northeast towards Iceland and the Faeroe Islands, but a considerable amount of tangential swell still expanded out towards the east and southeast. Between 15th and 18th local conditions were excellent for the beachbreaks in the southwest UK, with light to moderate winds from the south or southeast, and wave heights varying from about three to five feet.