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Pacific Storm and Surf Forecast
Updated: September 17, 2013 9:15 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 Forecast
Another To Follow Directly

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 Tuesday
(9/17) North and Central CA had surf at waist to maybe chest high and junky with northwest winds blowing and effectively chopped. Down in Santa Cruz surf was thigh high and cleaner but weak. In Southern California up north waves were thigh high from windswell and gutless but reasonably clean and somewhat rideable. Down south waves were waist high on the sets and clean but very weak. Hawaii's North Shore was settling some northerly windswell with waves shoulder high on occasion and clean but with a bit of morning sickness warble mixed Trades were light. The South Shore was still getting minimal tradewinds generated wrap around windswell mixed with background southern hemi energy at about waist high and clean. The East Shore was waist high tradewind generated windswell 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 high pressure as the name of the game, locked north of Hawaii and driving the storm track north up through the Bering Sea. The high was generating north winds along the California coast at 15-20 kt north winds down the coast making for short period junky north windswell along exposed breaks north of Pt Conception.

Relative to the Hawaii the high was generating easterly tradewinds at 15 kts with small easterly tradewind generated windswell being produced.   

But a quick look at the forecast charts suggests something far more interesting might develop in the Northeastern Gulf later in the week with a secondary gale forming directly behind it over the weekend. And there's potential for more behind that. Of course, that's all just a projection with no wind blowing on the oceans surface just yet. 

In the South Pacific 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. Otherwise another 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. Basically the Southern Hemi is going to sleep.  

Details below...

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

North Pacific

Jetstream  -  On Tuesday (9/17) the jet was still a bit disorganized but not completely a mess, with a generalized flow tracking west to east along the 50N latitude and just south of the Aleutians falling into a weak broad trough just off the coast of Northern CA. Winds were light other than a few pockets of energy to 120 kts and one pocket to 140 kts over the Kuril Islands, but no real support for gale development indicated. Over the next 72 hours wind energy 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 while easing slowly east and positioned just off the Oregon-CA border in the evening with 110 kt winds still pouring into it. Good support for gale development possible. Beyond 72 hours the Gulf trough is to push inland over Oregon Sat AM. At that time the whole jet is to fall south some with the dateline ridge still in.cgiace but peaking over the Central Aleutians (rather than up in the Bering Sea) with the Gulf trough rebuilding late and 130-140 kt winds pushing into it, and easing east into Washington on Monday (9/23). More support for gale development indicated. In all a very interesting early season set-up if one is to believe the model. But later Monday the ridge over the dateline is to become invigorated with 150 kt winds flowing northeast up into it with the ridge steadily moving east, into the Western Gulf by Tuesday and likely starting to shut gale production down at that time.  

Surface Analysis  -  On Tuesday (9/17) a broad high pressure system at 1028 mbs was in firm control centered 900 nmiles north of Hawaii and ridging west almost to Japan and east to Northern CA. As a result the usual pressure gradient was developing along the North and Central CA coast with north winds 15-20 kts and short period local north windswell was being generated. The high was also enhancing trades east of and over Hawaii at 15 kts making for modest easterly short period windswell pushing into exposed east shores of the Hawaiian Islands.  This high is eerily coincidental occurring in sync with the Inactive Phase of the MJO tracking over the Central equatorial Pacific.  

Over the next 72 hours the high is to rapidly retreat west and a new gale is to start building in the Central Gulf of Alaska Wed AM (9/18) with winds initially 30 kts. By evening pressure is to be down to 984 mbs with up to 45 kt north winds building over a tiny area in the gale west quadrant aimed towards California. 20 ft seas forecast over a pinpoint area at 47N 147W with 15 ft seas from the gales south quadrant pushing towards Oregon and North CA. By Thurs AM a nicely developed fetch of 40-45 kt northwest winds is forecast over a modest area in the gales southwest quadrant is expected with seas building over a smallish area there to 28 ft at 45N 143W (303 degs NCal). The gale to start lifting slowly north in the evening with winds still 40 kt solid over a moderate sized area off the Pacific Northwest coast with seas still 26 ft at 47N 140W (309 degs NCal). The gale to hold off the Canadian coast Fri AM (9/20) with northwest winds still 40 kts though shrinking in coverage with seas down to 22 ft at 48N 140W (313 degs NCal). By evening the gale is to fading out with winds barely 35 kts and seas dropping to 19 ft at 52N 140W dissipating and moving inland Sat AM (9/21). If this were to occur as forecast a nice little shot of well 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. It's certainly something to monitor. 

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 Tuesday (9/17) the following tropical systems were being monitored:

Tropical Storm Usagi was 600 nmiles east of the Northern Philippines tracking slowly west wind winds 40 kts.  A steady increase in winds speeds are forecast during the week with a turn to the northwest putting Usagi moving inland over Southern Taiwan Sat AM (9/21) with winds 90 kts. Usagi to continue northwest tracing into mainland China later Sunday. No swell production is forecast for this system relative to our forecast area.

The models continue to predict various small tropical systems trying to form in the West Pacific tracking north and northeast over the coming weekend (9/20).  But it's too early to believe any of that just yet.   

California Nearshore Forecast
On Tuesday (9/17) weak high pressure was ridging into the coast generating the normal 15 kt north wind flow from Cape Mendocino southward to Pt Conception then over the Channel Islands on into Baja.  Southern CA was somewhat protected.  The north flow is to come up more along the North and Central Coasts to 20 kts on Wednesday pushing 25 kts near Pt Conception. But by Thursday north winds are to be fading fast from 10-15 kts as low pressure moves towards the coast. A light flow is forecast Friday and Saturday with high pressure and north winds again rebuilding Sunday to 20 kts near Pt Conception and maybe 10-15 kts near San Francisco then fading some Monday as more low pressure approaches the coast. Light winds forecast Tuesday.       

South Pacific

Surface  - On Tuesday (9/17) high pressure at 1032 mbs was over the upper reaches of the Southeast Pacific driving the storm track there flat west to east and di.cgiaced well south down near 58S. No real swell production was occurring nor has occurred over the past week. 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. Maybe some sideband swell energy to push north into Southern CA with luck.

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 there's suggestions that yet another gale is to form in the Northern Gulf on Sat AM (9/21) with 35 kt northwest winds building over a solid area aimed towards the Pacific northwest. Seas building from 18 ft. By evening a solid fetch of 35-40 kt northwest winds is to be tracking east-southeast in the Gulf with seas building to 23 ft at 50N 155W (309 degs NCal).  35-40 kt northwest winds to continue tracing east Sun AM (9/22) with 26 ft seas forecast at 49N 145W (312 degs NCal). The gale to start fading in the evening with northwest winds barely 35 kts and seas fading from  barely 26 ft at 47N 140W (309 degs).  Mon AM (9/23) winds to fall below the 30 kt threshold with seas from previous fetch 20 ft at 45N 135W (310 degs NCal)  and tracking towards Oregon and Northern CA. Certainly something to monitor but too early to be believable.      

Unfortunately, Hawaii is to be well west of any of this activity. But there's suggestions of tropical weather building in the West Pacific on Sat (9/21) and getting sucked northeast tracking north up the back side of the residual high pressure north of Hawaii Mon-Tues (9/24). It is to get sheared and fade significantly, but the recurvature is something to take note of and to monitor, especially when and if it makes it to the Gulf of Alaska. It certainly is looking like Fall.  

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 Tuesday (9/17) the daily Southern Oscillation Index (SOI) fell to 16.64. The 30 day average was up to 2.70 with the 90 day average up some at 4.66. 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 neutral anomalies over the Maritime Continent turning lightly east on the dateline to a point south of Hawaii, then dying. Neutral anomalies continued from there into the coast of Central America. A week from now (9/25) neutral anomalies are forecast on the Maritime Continent continuing over the dateline region then turning slightly easterly south of Hawaii and continuing into Central America. In all this suggests the Inactive Phase of the MJO was barely hanging on over the dateline but is weaker than forecast and forecast to track east and fade a week out (a good thing).      

The longer range models (dynamic and statistical) run on 9/16 are in sync. Both models suggests an Inactive Phase was already fading over the East Pacific with the Active Phase building over the far West Pacific. This pattern is to hold effectively unchanged 5 and 8 days out, then finally starting to weaken 15 day out per the statistic model but still holding in the moderate category per the dynamic model.  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 the hold it has had on the Pacific all summer. The ultra long range upper level model suggests the Inactive Phase was already exiting over South America with the Active Phase setting up over the Maritime Continent. The Active Phase is expected to slowly track east over the Pacific through 10/9 with a modest Inactive Phase building behind that on 10/12, but then gone by 10/27 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 (9/16) a very weak and fading La Nina-like pattern is barely hanging on over the far East Pacific on the equator. A small pocket of cooler water that we've been monitoring off the immediate coast of Peru is fading yet more, and is nearly gone, with the weak outflow from it tracking to the Galapagos Islands, then dissipating west of there, breaking up into small pockets barely making it to a point half way to Hawaii. 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 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. At this point it looks like the Active Phase is getting the upper hand. The sympathetic anomalous cool pool off West Africa appears to have dissipated. Both these.cgiumes could resurge if a normal Inactive Phase develops. But all data is suggesting that is not going to happen. Will continue to monitor. 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 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. Looking briefly at the historical record this is the result of the seasonal 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 through the early summer, and in this case for two + years, now released and following the jet across the northern latitudes into the US West Coast. One thing is for sure, water temps are up in Central CA, the first time in a few years, pushing near 60 degrees. This appears to be the final demise of La Nina and the start of the Fall season. Looking at the big picture, cooler waters over the equatorial East Pacific are well under control, though still present and fading. 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. We're certainly nowhere near as cold as the previous 2 years.  

Subsurface waters temps on the equator indicate a neutral temperature pattern. Of some interest is a warmer tongue of +2.0 deg C water radiating east down 125 meters extending from a point south of Hawaii almost to Ecuador.  It certainly looks like a weak Kelvin Wave, but given the lack of strong Active Phase activity recently, that seems optimistic. Still it has progressed east and is now at 105W.  But it's certainly worth monitoring. For now we'll say no Kelvin Wave is present, but that could change.   

Projections from the CFSv2 model run 9/17 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 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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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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