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Pacific Storm and Surf Forecast
Updated: August 25, 2013 12:44 PM
Buoys: Northern CA - Southern CA - Hawaii - Gulf of Alaska - Pacific Northwest
Buoy Forecast:
Northern CA - Southern CA - Hawaii - Gulf of Alaska - Pacific Northwest
Pacific Links:  Atmospheric Models - Buoy Data - Current Weather - Wave Models
Forecast Archives: Enter Here
A chronology of recent Mavericks Underground forecasts. Once you enter, just click on the HTML file forecast you want to review (e.g. 073199.html equals July 31, 1999). To view the maps that correspond to that forecast date, select the html file labeled 073199 maps.html
Swell Potential Rating = 2.1 - California & 1.5 - Hawaii
Using the 'Summer' Scale
(See Swell Category Table link at bottom of page)
Probability for presence of largest swells in near-shore waters of NCal, SCal or Hawaii.    
Issued for Week of Monday 8/26 thru Sun 9/1
Swell Potential Rating Categories
5 = Good probability for 3 or more days of Significant swell
4 = Good probability for 1-2 days of Significant swell
3 = Good probability for 3 or more days of Intermediate/Advanced swell
2 = Good probability for  1-2 days of
Intermediate/Advanced swell
1 = Good probability for 3 or more days of Impulse or Windswell
0 = Low probability for 1-2 days of Impulse or Windswell   

Small Southern Hemi Swell Expected
Maybe Another Pulse Developing Under NZ Longterm

Swell Classification Guidelines

Significant: Winter - Swell 8 ft @ 14 secs or greater (11+ ft faces) for 8+ hours (greater than double overhead).
- Head high or better.
Advanced: Winter - Swell and period combination capable of generating faces 1.5 times overhead to double overhead (7-10 ft)
Summer - Chest to head high.
Intermediate/Utility Class: Winter - Swell and period combination generating faces at head high to 1.5 times overhead (4-7 ft).
- Waist to chest high.
Impulse/Windswell: Winter - Swell and period combination generating faces up to head high (1-4 ft) or anything with a period less than 11 secs.
- up to waist high swell. Also called 'Background' swell.

Current Conditions
On Sunday
(8/25) North and Central CA had surf that was thigh high with sets to waist high at top spots and clean early with no wind. Down in Santa Cruz surf was flat with sets to knee high and clean with no winds early. Southern California up north was flat and clean with light westerly wind. Down south waves were maybe thigh high and clean but totally obscured by fog. Hawaii's North Shore was flat and clean. The South Shore was flat and clean with trades in effect. The East Shore was getting tradewind produced east windswell at thigh to waist high and and chopped from trades.

See QuikCASTs for the 5 day surf overview or read below for the detailed view.

Meteorological Overview
In the North Pacific on Sunday (8/25) a weak pressure pattern was in control of the North Pacific with no large scale swell production occurring. A tropical system was in the West Pacific but not producing fetch aimed east. Another weak tropical system was just south of Cabo San Lucas but shadowed by Baja relative to our forecast area. Weak high pressure was over the Northern Dateline region with not even local northerly windswell suggested for California. Trades were up just enough to produce minimally rideable windswell for the east shores of the Hawaiian Islands.

Relative to California the local pressure gradient is non-existent with no fetch nor local windswell indicated. And no change is forecast for the workweek.

Relative to the Hawaii easterly tradewinds were barely reaching the 15 kt threshold and expected to hold into mid-Tuesday (8/27) before dropping out, with whatever minimal windswell they produce fading at that time.   

Over the past 7 days one small weak gale developed in the deep Central Pacific Monday (8/19) 25 ft seas aimed up at Tahiti, Hawaii and the US West Coast while slowly easing east, peaking late Tues (8/20) with seas to 32 ft over tiny area aimed only at the US West Coast down into Chile before fading Wed AM. Barely rideable 14-15 sec period swell is expected for our forecast mid-week. Beyond the models continue to predict a gale tracking under New Zealand Thurs (8/29) with 28-30 ft seas suggested aimed mostly east into Sat AM. Low odds for some minimal swell to result.  

Details below...

Current marine weather and wave analysis.cgius forecast conditions for the next 72 hours

North Pacific

Surface Analysis  -  On Sunday (8/25) the North Pacific high pressure system was retrograded west positioned over the northern dateline region at 1024 mbs with lesser high pressure trying to budge up to the US West Coast but unsuccessful at producing a pressure gradient or north winds capable of generating local northerly windswell. A neutral pressure pattern was off Japan to the dateline. Weak low pressure was in the northern Gulf of Alaska but non-productive. For the most part the high was too far north to produce easterly trades above the critical 15 kt threshold to produce much east windswell for the Hawaiian Islands either. Two tropical systems were being monitored (see Tropics section below). 

Over the next 72 hours the high is to drop south some resulting in a weak pressure gradient over the Hawaiian Islands with trades reaching the 15 kt threshold Monday and Tuesday good for bare minimal easterly windswell along exposed east facing shores. But relative to the California coast low pressure in the Gulf is to start falling southeast down the Canadian coast keeping high pressure well at bay with no windswell expected to be generated. And the low itself is to be too weak to generate any swell.

Otherwise no other swell producing fetch of interest is forecast.


  North Pacific Animations: Jetstream - Surface Pressure/Wind - Sea Height - Surf Height


On Sunday (8/25) the following tropical systems were being monitored:

What was Tropical Storm Pewa was 900 nmiles north-northwest of Wake Island and had degenerated to the point of no longer being even a tropical depression. The GFS model depicts so regeneration on Monday but then the system is to fade again, getting sheared by the jet Tuesday before being carried fast to the northeast over the top of high pressure just east of the dateline. Pewas remnants to maybe end up in the Gulf of Alaska on Sun (9/1) with winds barely 20 kts and not effective at any swell production.

Tropical Depression 9E has moved to a point 200 nmiles west of southern Baja Mexico on Sun AM (8/25) with winds 30 kts and tracking north-northwest. It was 600 nmiles from Dana Point CA on the 168 degree path, but so weak as to be producing only 14 ft seas with no swell of interest resulting. 9E is expected to continue that heading moving parallel to the western Baja coast into Tuesday but with winds fading to 20 kts with even less swell production capacity indicated. No swell to result.

The GFS model hints at more tropical activity for the area South of Cabo by late in the workweek, but none of that is believable at this early date.

California Nearshore Forecast
On Sunday (8/25) weak high pressure at 1020 mbs was centered mid-way between Hawaii and California while weak low pressure was over the Gulf of Alaska down to British Columbia holding even the weak high pressure at bay and making for a generally weak 10-15 kt northerly wind flow over coastal waters of North and Central CA. This gradient is to dissipate Monday as more low pressure moves into the Gulf of Alaska and falls south into Wednesday with a weak front perhaps reaching to the Oregon-California border. North winds 15 kts forecast for Pt Conception and just outside the Channel Islands, but nothing more. The low to push off the Northern CA coast Thursday moving towards Oregon into the weekend with north winds dissipating even more over the weekend other than a small area of 15 kt north winds over Pt Conception. Southern CA to remain under a light wind flow for the duration.


South Pacific

Jetstream  -  On Sunday (8/25) the jet was .cgiit over the Southwest Pacific with the southern branch tracking over the northern edge of the Ross Ice Shelf and effectively landlocked offering no support for gale development in the upper levels of the atmosphere. The southern branch tracked north forming a very weak trough near 120W on the eastern edge of the California swell window, much as it has for weeks now, but with winds only 980 kts or less offering no support for gale development. A big ridge was east of there over South America. Over the next 72 hours the same pattern is to hold but with the ridge in the west starting to weaken and the southern branch moving up to near 55S just southwest of New Zealand by Monday (8/26), at least positioned better. But over the remainder of the greater Pacific the jet is to fall south and run flat along the 70S latitude, over Antarctic Ice and offering no support for gale development. Beyond 72 hours a better trough like pattern is to build under New Zealand starting late Thursday (8/29) with 140 kt winds building into the trough and easing east into the far West Pacific Friday perhaps offering limited support for gale development in the upper levels of the atmosphere. But that trough, assuming it even forms, is to be weakening steadily as it pushes east and starting to pinch off by Sun (9/1). At least there's something to monitor.  

Surface  - On Sunday (8/25) high pressure at 1028 mbs was east of New Zealand ridging south to 62S driving all east moving gales into Antarctica. No swell producing fetch was indicated.  Over the next 72 hours no real change is forecast with the high building to 1032 mbs and tracking east continuing to ridge south to 62S with the same effect as earlier. But a small poorly organized gale is to track under New Zealand on Tuesday (8/27) producing a short lived fetch of 40 kt west winds falling southeast with seas building to 28-30 ft over a tiny area at 58S 178W, but they too are to be falling southeast and weakening all the while, crossing over the Ross Ice Shelf in the evening and offering no support for swell development.   


Gale 3
On Sunday (8/18) a weak gale developed in the Central Pacific but abutted against solid high pressure at 1028 mbs under New Zealand setting up a nice pressure gradient producing 40 kt south winds just north of the Ross Ice Shelf with the whole fetch lifting slowly due north. Seas built to 23 ft at 55S 160W in the evening. On Monday AM (8/19) winds faded to 35 kts over the same area of the ocean with seas 25 ft at 53S 155W pushing die north, with more of the same in the evening with seas 25 ft at 49S 150W. Tuesday AM (8/20) winds were still 35 kts from the south with seas holding at 25 ft at 48S 144W. Fetch built to 45 kts in the evening over a small area with seas building to 30 ft at 53S 132W. The gale was fading Wed AM (8/21) with winds dropping from 40 kts out of the south over a small area and seas 32 ft at 50S 130W. The gale was gone by the evening. 

If all goes as forecast some degree of rideable 15 sec period swell to result for Tahiti, Hawaii, and the US West Coast. 

Swell to arrive in Hawaii on Tues (8/27) building to 1.3 ft @ 14-15 secs (2 ft) later. Swell of 1.6 ft @ 13 secs (2 ft) continues Wed (8/28), then fading. Swell Direction: 175 degrees  

Swell to arrive in SCal on late Wed (8/28) at 1.5 ft @ 16 secs (2.0-2.5 ft) peaking Thurs (8/29) at 2.2 ft @ 14-15 secs (3.0-3.5 ft).  Dribbles on Fri (8/30) fading from 2.2 ft @ 14 secs early (3 ft). Swell Direction: 195 degrees.    

Swell to arrive in NCal later Thurs (8/29) at 1.5 ft @ 16 secs (2.0-2.5 ft) peaking Fri (8/30) at 2.0 ft @ 15 secs (3.0 ft).  Dribbles on Sat (8/31) at 2.2 ft @ 14-15 secs (3 ft). Swell Direction: 192 degrees.    


South Pacific Animations: Jetstream - Surface Pressure/Wind - Sea Height - Surf Height




Marine weather and forecast conditions 3-10 days into the future

North Pacific

Beyond 72 hours high pressure is to continue circulating just east of the dateline and 1200 nmiles north of Hawaii at 1028 mbs on Wed (8/28), too far away from the US West Coast to be of any interest but generating a weak northeasterly flow over the Hawaiian Islands but below the 15 kt mark, with no windswell of interest resulting. No real change forecast through Sun (9/1) with the high easing a bit more south and east but weakening with the same result - nothing for the US West Coast or Hawaii.

The models suggest weak low pressure holding off the coast of British Columbia through the work week into the weekend (9/1) with high pressure in the Central Pacific forming a weak gradient with periods of up to 20 kt northwest winds developing between the two targeting the Pacific Northwest, but no windswell of rideable size to survive the longish journey to the US West Coast.  

Note: The Madden Julian Oscillation is a periodic weather cycle that tracks east along the equator circumnavigating the globe. It is characterized in it's Inactive Phase by enhanced trade winds and dry weather over the part of the equatorial Pacific it is in control of, and in it's Active Phase by slack if not an outright reversal of trade winds and enhanced precipitation. The oscillation occurs in roughly 20-30 day cycles (Inactive for 20-30 days, then Active for 20-30 days) over any single location on the.cgianet. During the Active Phase in the Pacific the MJO tends to support the formation of stronger and longer lasting gales resulting in enhanced potential for the formation of swell producing storms. During the Inactive Phase the jet stream tends to .cgiit resulting in high pressure and less potential for swell producing storm development. The paragraphs below analyze the state of the MJO in the Pacific and provide forecasts for MJO activity (which directly relate to the potential for swell production).

As of Sunday (8/25) the daily Southern Oscillation Index (SOI) was back down to -12.69. The 30 day average was down to 0.73 with the 90 day average down some at 6.17. The nearterm trend based on the SOI was indicative of a weak Active Phase of the MJO while overall the pattern was still in weak La Nina territory and not indicative of El Nino and illustrative of a dominance of the Inactive Phase of the MJO.  

Current equatorial surface wind analysis indicated light easterly anomalies over the Maritime Continent turning neutral over the dateline and turning light westerly from there to a point south of Hawaii. Westerly anomalies extended a bit beyond there then turning neutral on to the coast of Central America. Of note - there has been a distinct lack of true prolonged westerly anomalies for months, so any hint of a westerly anomaly is a good thing. A week from now (9/1) weak easterly anomalies are forecast developing over the extreme West Maritime Continent fading to neutral and turning westerly over the dateline region and continuing on to a point south of Hawaii. Neutral anomalies are forecast holding almost into Central America. In all this suggests a slight Active Phase of the MJO is in.cgiay pushing east.    

The longer range models (dynamic and statistical) run on 8/24 are in general agreement. Both models suggests a weak Inactive Phase is starting to take hold over the far West Pacific. This pattern is to continue per both models over the next 15 days with the peak expected 8-12 days out per both. The ultra long range upper level model suggests the Active Phase was exiting east over the far East Pacific while the Inactive Phase was building in the West Pacific and is to hold through 9/14, then falling back towards a neutral pattern if not light Active Pattern by 9/19 continuing into early October.  

The more warm water in the equatorial East Pacific means more storm production in the North Pacific during winter months (roughly speaking). Cold water in that area has a dampening effect. Regardless of what the atmospheric models and surface winds suggest, actual water temperatures are a ground-truth indicator of what is occurring in the ocean. As of now (8/22) a very weak La Nina-like pattern continues in the East Pacific on the equator. The small pocket of cooler water we've been monitoring off the immediate coast of Peru is starting to recharge slightly, with the outflow from it tracking to the Galapagos Islands, then fading west of there, breaking up into small pockets of cooler water radiating west almost to a point south of Hawaii. Imagery from 8/5-8/15 suggested the cool pool had been re-generating, but the 8/19 image suggested a warming trend in.cgiay, likely the result of a weak Active Phase taking root. Historically this is no different from what has been occurring all summer with the cool pool fluctuating and sporadically spitting occasional larger pockets of cool water westward along the equator and keeping a lid on any legitimate warm water from developing. The sympathetic anomalous cool pool off West Africa appears to be loosing some ground recently as the Active Phase gets a toe in the door. It had previously built almost to the coast of South America then retrograded in late June. The African cool pool is a direct reflection of what has been occurred in the Pacific, an unexpected burst of cool water gurgling up off both the South America and West Africa coasts simultaneously - suggestive of a global teleconnection. Further north a.cgiume of slightly cooler than normal water that has been radiating southeast off California for 2 years closed off mid-May, returned in June when the cold pool emerged off Peru and Africa, then fully closed off in July.  8/12-8/22 it appeared to be rebuilding off the California coast with a small but well defined track radiating off California almost reaching a point south of Hawaii. But a considerable pocket of warmer than normal water is also building west of California tracking east and now signs of abating, so it's anyone guess whether the local pool will get mowed over by the eastward moving warm pool. Once thing is for sure, water temps are up in Central CA, the first time in a few years. Looking at the big picture, cooler waters over the equatorial East Pacific are under control, but still present, with no sign of a legitimate warm pattern developing. In short, we're still under some weak influence of La Nina or at least a neutral pattern biased slightly cool. But we're nowhere near as cold as the previous 2 years.   

Subsurface waters temps on the equator indicate a neutral temperature pattern. Warm water from the West Pacific previously migrated east over top of a cold pool - eliminating it's impact and continues holding.

Projections from the CFSv2 model run 8/25 indicate water temps have been hovering near neutral since January within only a +-0.25 deviation. Recent runs of the model have consistently been suggesting a bit if a turnaround with a warming trend (up to +0.25 degs C) taking hold by September into Oct 2013 and up to near +0.6 C by April 2014. This would suggest a weak El Nino possible for next year. But for the immediate future a neutral pattern is expected. So overall the immediate outlook remains nothing stellar, but trending towards something that would be considered right on the threshold of warm, by Spring 2014, assuming one were to believe the model. This is good news. If anything the ocean is in a recharging mode, with cold water dispersing and temperatures gradually on the rise again in fit's-and-starts. Historically, if a warm water buildup indicative of any kind of El Nino pattern were to occur in 2013, it would have started building in Feb-Mar. That is clearly not the case for this year. Expect a neutral pattern for Winter of 2013-2014 with perhaps a slightly warmer pattern by early 2014. 

We are in a neutral ENSO pattern with neither a solid El Nino or La Nina imminent. But a weak prevalence of the Inactive Phase of MJO seems to be biasing the weather global pattern. This is a better.cgiace than previous years (2010-2011, 2011-2012 and 2012-2013) under the direct influence of La Nina, but we're still not in a pure neutral pattern either. We're still recovering from the 2009-2010 El Nino. Longer term the expectation is there will be at least one to two years of neutral temperatures ultimately converging in a stronger warmer pattern and possible El Nino 2-3 years out (2015 or 2016). And historically, this is the 'normal' pattern (a few years of false starts post La Nina before a legit El Nino forms).

See imagery in the ENSO Powertool and more details in the  El Nino Update Last Updated 10/6/12 


South Pacific

Beyond 72 hours another gale is forecast tracking under New Zealand on Thurs (8/29) with 45 kt west winds turning more southwesterly later in the day aimed better to the northeast. Seas building to 32 ft at 54S 172E. Winds fading to 40 kts on Friday and lifting a little northeast with seas down to 30 ft pushing up to 51S 169W late. If all goes as forecast (not likely at this early date) tiny swell is possible for Tahiti, Hawaii and up into California. But its a long ways from reality. Otherwise no swell producing fetch is forecast.

Details to follow...


External Reference Material: El Nino Southern Oscillation (ENSO), Madden Julian Oscillation (MJO), Pacific Decadal Oscillation (PDO), Southern Oscillation Index (SOI), Kelvin Wave

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Local Interest

Visit! Boardshorts - Looking for a sick pair of boardshorts? Check out the selection at with brands from O'Neill, Quiksilver and Rusty and free shipping on every order. They won't disappoint.

Wall of Skulls - Here's a great video featuring Tahiti's famous wave. There's also a nice little.cgiug for Stormsurf in it too.

Super Natural - Powerlines Productions has released their new big wave surf video chronicling the epic El Nino winter of 2009-2010.cgius many other big wave event through the 2012-2013 winter season. It's a must see event for any big wave rider. It's for sale here:

Nantucket Marine Mammals has documented a short video concerning whale conservation and awareness off the Northeast US Coast. See it here:

Jason-1 Satellite Decommisioned - On June 21 an error occurred on board the Jason-1 satellite and it automatically shut down all critical functions. The satellite has since officially been decommissioned. It's last working transmitter failed on 6/21. All efforts have been made to get a response to no avail. The satellite has been.cgiaced in a parking orbit with it's solar panels turned away from the the sun. It's batteries are to discharge in the next 90 days. No additional data is expected from this satellite. We are working to start capturing data from the Jason-2 satellite, but that will take some time. More information to follow.

'CBS This Morning' with the Mavericks Invitational Surf Contest - See a nice morning TV show piece on the Mavericks Contest held Sun 1/20/13. The show aired Wed 1/23. Interviews with Colin Dwyer, Jeff Clark, Mark Sponsler and Grant Washburn:

Jaws Redbull Contest Forecast E.cgiained By Stormsurf

Cortes Bank Mission (12/21-12/22/2012)

The Making of 'Chasing Mavericks' - See some background footage on how the movie was made: Part1, Part2

The Psychology of Big Wave Surfing with Greg Long - A must see for any aspiring big wave rider:

Greg Long XCel Core Files - Here's a great profile of Greg Long and his contributions toward pushing the state of big wave surfing. Well Done -

Chasing Mavericks - The Jay Moriarty Movie: Two trailers for the new movie about Jay, Frosty and Mavericks has been posted. Movie opens on 10/26/12. Here's the link: &

Props from the Pros:  Stormsurf was mentioned over the past week in two different media sources.  One was in an interview Kelly Slater did with the New York Times and another was in a promotional piece Ramon Navarro did for the Big Wave World Tour. Many thanks to Curt Myers from Powerline Productions for alerting us and of course thanks to Kelly, Ramon and the Tour for using our service. Here's the links:

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New Wave Model Facts: Click HERE to read more about the new wave models. Important info.

Time Zone Converter By popular demand we've built and easy to use time convert that transposes GMT time to whatever time zone you are located. It's ion left hand column on every page on the site near the link to the swell calculator.

Stormsurf Google Gadget - Want Stormsurf content on your Google Homepage? It's si.cgie and free. If you have Google set as your default Internet E.cgiorer Homepage, just click the link below and a buoy forecast will be added to your Google homepage. Defaults to Half Moon Bay CA. If you want to select a different location, just click on the word 'edit', and a list of alternate available locations appears. Pick the one of your choice. Content updates 4 times daily. A great way to see what waves are coming your way! .xml

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Surf Height-Swell Height Correlation Table


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