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Pacific Storm and Surf Forecast
Updated: September 19, 2013 5:21 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 = 2.5 - California & 1.0 - Hawaii
Using the 'Winter' 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 9/16 thru Sun 9/22
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   

Gulf Gale Forms - Small Swell for West Coast
Another To Follow In the Gulf

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 Thursday
(9/19) North and Central CA surf was waist to near chest high on the sets and clean but weak with light winds and near glassy conditions. Down in Santa Cruz surf was knee high and clean. In Southern California up north waves were thigh high from windswell and weak but clean, barely rideable. Down south waves were waist high on the sets and a bit textured and generally weak. Hawaii's North Shore was flat and clean. The South Shore was getting minimal southern hemi background swell at thigh to maybe waist high and clean. No report was available for the East Shore.

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

Meteorological Overview
In the North Pacific a gale was developing off the coast of Washington and starting to produce some decent seas, but nothing remarkable. But given it's close proximity to the Pacific Northwest and California, some swell is expected for all location north of Pt Conception. Tropical activity was in the far West Pacific but not curving north or northeast at this time. High pressure was north of Hawaii but was starting to be repulsed relative to California by the Gulf gale, with windswell generation potential there fading out.

Relative to the Hawaii was not quite in the right position to generating easterly tradewinds exceeding the 15 kt threshold, with no real easterly tradewind generated windswell being produced.   

But a quick look at the forecast charts suggests the Gulf Gale was about peaked out and expected to fade over the next 24 hours. The good news is another gale is to be forming directly behind it over the weekend fading into Monday (9/23). Strong high pressure is to follow, but theoretically tropical low pressure is to be streaming north up the western flank of the high approaching the dateline. Maybe something to develop, but it's way too early to know with any certainty.

In the South Pacific a tiny system formed under New Zealand on Sun (9/15) tracking northeast with seas to 31 ft for 18 hours. Maybe some minimal energy for Tahiti and even less for Hawaii. Also a weak gale formed on the eastern edge of the California swell window late Monday (9/16) with seas to 30 ft pushing to 32 ft Tues AM, but tracking flat east with little energy pushing due north. Most energy was targeting Southern Chile. Maybe some bare minimal background energy for mainly Southern CA with luck. Beyond and area of 28 ft seas was developing southeast of New Zealand today and another forecast in the Central South Pacific on Wed (9/25) again at 28 ft, but nothing remarkable.   

Details below...


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

North Pacific

Jetstream  -  On Thursday (9/19) the jet was tracking off the Kuril Islands then ridging hard north up into the Bering Sea at 130 kts, before turning southeast and falling into a developing but steep trough in the Eastern Gulf of Alaska with winds there also to near 120 kts. Good support for gale development in this trough. From there the jet headed north tracking into northern British Columbia. Over the next 72 hours wind energy from the Central Pacific portion of the jet is to be falling hard southeast into the Gulf trough Friday over the Kuril Islands is to rapidly build east, forming a small trough over the Kuril Islands on Thurs (9/19)  ridging north into the Bering Sea near the dateline then falling firmly southeast into the Eastern Gulf forming a nice trough there with 120 kt winds flowing into it and bottoming out 900 nmiles west of Cape Mendocino CA. The trough to hold Friday through Sunday (9/22) at 130+ kts continuously providing good support for gale development through the period. Beyond 72 hours the Gulf trough is to continue holding while tracking east, with the apex of the trough finally pushing inland over Oregon later Tuesday (9/24) and reaching south to the San Francisco area early Wednesday before moving totally inland. Limited support for gale development into late Monday. Later Monday the ridge over the dateline is to start pushing into the Gulf shutting gale potential down there. Another big ridge is forecast building over the dateline pushing up into the Bering Sea with winds to 170 kts on Thurs (9/26). There's some potential for this energy to spill into a trough in the Gulf beyond if one is to believe the models.

Surface Analysis  -  On Thursday (9/19) a gale was building in the Eastern Gulf (see Gulf Gale below). Otherwise broad high pressure at 1024 mbs was in firm control over the dateline but not ridging into California and barely into the western Hawaiian Islands. No windswell was being generated.

Over the next 72 hours a mixture of tropical and Siberian energy to converge over the Eastern Aleutians dropping southeast into the Northern Gulf of Alaska on Sat AM (9/21) with west winds forecast at 35-40 kts over a solid sized area targeting mainly Canada with seas building to 22 ft over a modest area at 53N 158W. By evening winds to turn more northwest and holding at 35 kts with seas building to 25 ft over a decent area at 51N 151W (311 degs NCal). On Sun AM (9/22) a solid fetch of 40 kt northwest winds is to build in the Northern Gulf aimed at Oregon with 30 kts fetch just off the coast there. Seas building to 27 ft over a good sized area at 49N 144W (314 degs NCal). Winds to hold into the evening unchanged with seas 28 ft at 52N 146W (317 degs NCal). By Monday AM (9/23) 35 kt northwest winds to be fading in the Eastern Gulf with seas fading from 27 ft at 52N 143W (319 degs NCal). In the evening 30-35 kt northwest winds to be fading off the coast of Canada with 22 ft seas on the edge of the NCal swell window 50N 140W (319 degrees) and fading. If all goes as forecast some very north angled 15 sec period swell could result for Central and North CA with more size north of there but also good odds for poor weather. No energy is expected arriving in Hawaii.


Gulf Gale
A new gale started building in the Central Gulf of Alaska on Wed AM (9/18) with winds initially 30 kts. By evening pressure was down to 984 mbs with 35-40 kt north winds building over a tiny area in the gale northwest quadrant aimed towards California. 18 ft seas were modeled over a tiny area at 42N 149W (290 degs NCal, 296 SCal) aimed towards the area from Oregon down to Central CA. By Thurs AM a modestly developed fetch of 40 kt northwest winds was occurring over a small area in the gales southwest quadrant with seas building over a smallish area there to 25 ft at 47N 143W (308 degs NCal). The gale to start lifting slowly north in the evening with winds still 40 kt solid over a small sized area off the Pacific Northwest coast with seas down to 23 ft at 46N 137W (308 degs NCal). The gale is to be fading fast off the Canadian coast Fri AM (9/20) with northwest winds 35 kts with seas down to 18 ft at 50N 135W. By evening the gale is to be gone and moving inland over the Central Canadian coast.

Given current modeled projections, a modest shot of rideable swell in the 13-15 sec range could result focused from Pt Conception northward into Oregon with the core near San Francisco up to Cape Mendocino. This gale is to mostly east of the Hawaiian swell window though some sideband energy is forecast arriving on Sun (9/22). See QuikCASTs for details.

North CA: Expect swell arrival from the first part of the fetch Friday (9/20) late afternoon building to maybe 4 ft @ 12 secs late from 290 degrees. The core swell to arrive near 11 PM with swell 6 ft @ 15 secs (9 ft), with period fading to 13 secs near sunrise (7.5 ft). Swell Direction: 308 degrees  

Southern CA: Expect core swell arrival Saturday near sunrise and building, peaking around noon at 2.4 ft @ 15 secs (3.5 ft) and holding through sunset as period starts fading. Swell only hitting breaks with excellent north exposure. Limited lesser period energy for most other breaks. Swell Direction:312 degrees

Otherwise the gradient associated with high pressure is to peak along the North and Central CA coast on Wed (9/18) with northwest winds 20-25 kts and trades over Hawaii still 15 kts, then breaking up fast Thursday as the gale (above) starts taking control. More local windswell to result until the gale takes over. See QuikCASTs for local windswell detail.    


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


On Thursday (9/19) the following tropical systems were being monitored:

Super Typhoon Usagi was located 300 nmiles east of the northern most Philippines tracking steadily west-northwest with sustained winds 140 kts (160 mph and gusts to 200 mph).  Seas were 42 ft. This motion is to continue with the storm slowly loosing speed, and threading the gap between the Northern Philippines and southern Taiwan late Friday night. Usagi is expected to make landfall over Hong Kong Sunday mid-day GMT (9/22) with winds down to 90 kts (104 mph). No swell production is forecast for this system relative to our forecast area.

The models continue to predict another system trying to form directly behind Usagi in the West Pacific late Fri (9/20) tracking north and then northeast off Japan on Thurs (9/26).  But it's too early to believe any of that just yet.   

California Nearshore Forecast
On Thursday (9/19) remnant high pressure was trying to ridge into the coast but was being rebuffed by a local gale off the Pacific Northwest. A light northerly wind flow was in.cgiay for much of the North and Central Coast with light winds into Southern CA. A light flow is forecast Friday with a low pressure wave trying to push into the Central Coast late morning. Still light winds forecast. Light rain for Northern CA. A repeat Saturday with another wave pushing into the Central Coast and winds turning light south. Light rain possible down to Monterey Bay later with 1-2 inches of snow for the high elevations of the Central Sierras late. Sunday high pressure is to try and get a toe in the door, but low pressure in the Gulf to deflect it. Still north winds to 20 kts are forecast near Pt Conception. Monday high pressure to start building with north winds getting footing over the Central Coast late at 15 kts with light rain for the North Coast. Wind north at 15 kts everywhere Tuesday and pushing 20 kts over Pt Conception. Wednesday high pressure to be in control with a gradient and 20 kt north winds forecast for the entire state late, starting to fade and ease northward on Thursday.

South Pacific

Surface  - On Thursday AM (9/19) high pressure at 1036 mbs was over the upper reaches of the Southeast Pacific driving the storm track there southeast with any fetch aimed at Antarctica. Southeast of New Zealand a small gale was generating 45 kt west to southwest winds producing seas to barely 28 ft over a tiny area, expected to peak in the evening still at 28 ft but over a modest sized area at 52S 166W. The gale is to be fading and falling southeast on Saturday (9/21) bound for the Ross Ice Shelf. Maybe a small pulse of 15 sec sideband background swell to result for Tahiti and Hawaii with luck. Otherwise over the next 72 hours no swell production is forecast. 


A gale developed in the Southeast Pacific on Monday PM (9/16) with 45 kt west winds generating 30 ft seas at 57S 130W. The gale raced east Tues AM (9/17) with winds down to 40 kts and seas 34 ft at 55S 117W (just outside even the SCal swell window) and targeting Southern Chile. At this time not even minimal sideband swell energy is to reach Southern CA.

Also a tiny gale formed under New Zealand on Sun AM (9/15) producing a tiny area of 45 kt southwest winds tracking northeast though the evening. Seas built to 31 ft for 18 hours centered on Sunday PM at 54S 171E. Maybe some minimal energy for Tahiti and even less for Hawaii stating Mon (9/23) 1.3 ft @ 16-17 secs (2 ft faces). Swell to continue Tues (9/24) at 1.4 ft @ 14-15 secs (2 ft) then dissipating. Swell Direction: 195 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 another batch of high pressure is forecast tracking from the Kuril Islands to the dateline MOn-Wed (9/25) building to 1036 mbs and driving the storm track mostly up into the Bering Sea. It's too early to tell if any strong energy tracking north of there will fall down into the Gulf of Alaska. But even if it did, it would be very close to the Canadian coast.  That said, a tropical system off Japan is to track north up the back side of this high and possibly join with Siberia low pressure in the Bering Sea. Something to monitor come about 9/30.

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 Thursday (9/19) the daily Southern Oscillation Index (SOI) jumped to 21.22. The 30 day average was up to 4.62 with the 90 day average up some at 4.97. We are in a weak Inactive Phase of the MJO. The nearterm trend based on the SOI was indicative of a weak Inactive Phase of the MJO while overall longer term pattern was neutral if not still in weak La Nina territory and not indicative of El Nino.  This was illustrative of a dominance of the Inactive Phase of the MJO.  

Current equatorial surface wind analysis indicated east anomalies over the Maritime Continent in pockets turning very lightly east on the dateline continuing south of Hawaii almost half way to South America, then dying. Neutral anomalies continued from there into the coast of Central America. A week from now (9/27) neutral anomalies are forecast on the Maritime Continent continuing over the dateline region then turning barely easterly south of Hawaii before falling back to neutral and continuing into Central America. In all this suggests the Inactive Phase of the MJO was falling apart on the dateline and points east of there and is forecast to track east and fade a week out (a good thing) with a weak Active Phase behind.     

The longer range models (dynamic and statistical) run on 9/18 are in sync. Both models suggests the Active Phase was already in control of the far West Pacific. This pattern is to hold effectively unchanged for the next 15 days.  This is all good news in that the Inactive Phase was weaker than expected and died faster than expected, and the Active is coming in nicely and is to hold for a good amount of time. Maybe the Inactive Phase is finally loosing its hold over the Pacific that it has had all summer. The ultra long range upper level model suggests the Active Phase is already set up over the Maritime Continent and is expected to slowly track east over the Pacific through 10/9 with a modest Inactive Phase building behind that on 10/09, but then gone by 10/29 with the Active Phase again starting to take over. The upper level model tends to be a leading indicator, with surface level anomalies lagging behind 1 week or more.   

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 (9/19) an exceedingly weak and fading La Nina-like pattern is all but gone over the far eastern equatorial Pacific. A small pocket of cooler water that we've been monitoring off the immediate coast of Peru is gone now, with the weak outflow from previous remnants of it tracking to the Galapagos Islands, then dissipating west of there. Imagery for Sept indicates this pattern has continued to dissipate, likely the result of a weak Active Phase of the MJO occurring simultaneously. Historically this is starting to be a departure from what has been occurring during the summer (with a cool pool off Peru fluctuating and sporadically spitting pockets of cool water westward along the equator). At this point it looks like the Active Phase is starting to get the upper hand. The sympathetic anomalous cool pool off West Africa is gone. Further north a.cgiume of slightly cooler than normal water that had been radiating southeast off California for 2 years is all but gone. Instead a wall of warmer than normal water that previously built off Japan has migrated east, slamming into California on 9/5 with thousands of nmiles of warmer water behind it moving east. No change is forecast. This is the result of the collapse of high pressure and north winds off the California coast (suppressing upwelling). And it also appears to be part of a oceanic exchange of warm water that has been pent up in the far tropical West Pacific for two + years, now released and following the jet across the northern latitudes into the US West Coast. This appears to be the final demise of La Nina and the start of the Fall season. But there's no sign of a legitimate warm pattern developing. In short, we're in a neutral pattern (and were tempted to say it's no longer biased slightly cool). A significant transition appears to be in.cgiay.

Subsurface waters temps on the equator indicate a neutral temperature pattern. Of some interest was a warmer tongue of +2.0 deg C water that was radiating east down 125 meters extending from a point south of Hawaii almost to Ecuador.  But as of today it has dissolved. No Kelvin Wave is present, but no cold pool is present either.    

Projections from the CFSv2 model run 9/19 remain unchanged. The model indicates 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 turnaround with a warming trend (up to +0.25 degs C) taking hold by September into Oct 2013 (+0.2 C) and up to near +0.4-0.5 C by Nov holding till the end of the model run on May 2014. This would suggest a weak El Nino possible for next year. But for the immediate future a neutral pattern is expected. 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. Other models suggest a continuation of neutral conditions. All this is good news. If anything the ocean is in a recharging mode, with cold water from the 2010-2011 La Nina 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 still 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 no swell producing fetch of interest 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

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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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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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