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Pacific Storm and Surf Forecast
Updated: August 15, 2013 9:53 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 = 0.5 - California & 1.0 - 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 8/12 thru Sun 8/18
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   

Windswell Expected for the Weekend in CA
Windswell to Fade for Hawaii

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
(8/15) North and Central CA had surf that was knee to thigh high and clean with heavy overcast - June gloom. Down in Santa Cruz surf was flat with a light winds and clean.  Southern California up north was flat and clean. Down south waves were knee high on the sets and clean with light overcast. Overall it was a lake. Hawaii's North Shore was flat and clean. The South Shore was getting waist to near chest high tradewinds generated wrap-around windswell and clean with trades in effect. The East Shore was getting easterly tropically enhanced windswell at waist to chest high 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 Thursday (8/15) a continuation of a weak pressure pattern was in effect over the Northeast Pacific and no swell producing fetch of interest was occurring
. But there's a glimmer of light at the end of the proverbial tunnel. Low pressure is to be moving through the Northern Gulf of Alaska over the weekend generating 25 kt west winds and 13 ft seas possibly setting up some northerly windswell for the US West Coast next week.  And the local pressure gradient is to warm up for Cape Mendocino, possibly providing an additive local windswell component relative to North and Central CA.    

Relative to California no local north fetch of interest was occurring. But by Sun (8/18) a weak return of the Cape Mendocino summer pressure gradient is forecast with north winds projected to 25 kts resulting in increased local short period windswell for North and Central CA by late in the weekend and holding for at least a few days.  

Relative to the Hawaii easterly tradewinds were blowing at 15 kts due to a combination of building high pressure north of the Islands and semi tropical low pressure tracking west and positioned south of the Islands forming a weak pressure gradient. Trades to remain in the 15 kt range through Saturday due to this situation, then fading some Sunday and all but gone by Monday as high pressure gets eroded some by low pressure in the Gulf.  Rideable windswell to continue along exposed east facing shores for the early weekend, then fading to flat by next week.   

Over the past 7 days no swell producing weather system of interest have occurred in the South Pacific. And looking forward no storms of interest are forecast. A southern hemi swell drought is well underway and entrenched, expected to continue for the foreseeable future. It's all on the shoulders of the North Pacific now.   Conversely, a healthy and consistent storm pattern is forecast under Southern Australia. 

Details below...

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

North Pacific

Surface Analysis  -  On Thursday (8/15) the North Pacific high pressure system was getting somewhat better organized at 1024 mbs centered  about 950 nmiles northwest of Hawaii and easing east. Weak low pressure was off Vancouver Island producing no fetch while a stronger system was in the East Bering Sea and landlocked. In all only the high pressure system was doing anything, if you could call it even that, producing 15 kt east winds (trades) pushing over Hawaii in conjunction with weak tropical low pressure south of the Islands resulting in small east windswell along exposed east facing shores.   

Over the next 72 hours the high is to continue sliding east while the low in the Bering Sea migrates southeast into the Northern Gulf of Alaska starting to generate 20-25 kt west winds Friday (8/16) continuing through the weekend targeting primarily Vancouver Island down into the Pacific Northwest with seas building to a very modest 13 ft Sat-Sun (8/18).  Windswell likely for those targets. 

Relative to California high pressure is to start getting a nose into the north end of the state late Saturday producing a small gradient and north winds just off North California at 20-25 kts into Sunday resulting in small northerly short period windswell for most of north and Central CA.  

Relative to Hawaii weak high pressure at 1024 mbs is to slowly track east positioned north of the Islands Friday and Saturday  (8/17) generating a weak easterly flow over the Islands with trades just barely at the 15 kt threshold and tradewind generated east windswell remaining in the barely rideable range. Weak tropical low pressure (not even depression status) is modeled also tracking west positioned 300 nmiles south of the Islands at the same time perhaps enhancing trades to the 20 kt range resulting in steady rideable easterly windswell along exposed shores. But by mid-day Saturday any trades are to be due to only high pressure north of the Islands, as the tropical low pressure passes west of Hawaii.  

Otherwise no other swell producing fetch of interest is forecast.


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


On Thursday (8/15) no tropical systems of interest were being monitored nor forecast.  

California Nearshore Forecast
On Thursday (8/15) a weak local northerly wind flow was in control of the entire California coast with winds 10 kts over outer water and maybe 15 kts near Pt Conception. Weak low pressure was tracking east through the Eastern Gulf of Alaska off the Pacific Northwest keeping high pressure at bay. Friday a generally weak pressure pattern is to continue with a weak north wind flow forecast reaching to 15 kts only over Pt Conception.  By Saturday the low dissipates with a more normal high pressure pattern setting up with 15 kt north winds in the afternoon for all of North and Central CA and up to 20 kts near Pt Conception. 20-25 kt north winds are forecast for Cape Mendocino on Sunday (8/18) with north winds 15 kts pushing down the outer Central Coast and north windswell on the upswing. By Monday a gradient is to be developed over Cape Mendocino with north winds 25 kts there (30 kts late) and a full eddy flow in control of the Central and South coasts, holding into mid-Tues (8/20). On Wednesday the gradient is to start fading with north winds dropping to 20 kts over North CA with a weaker eddy flow nearshore for Central CA. Thursday the gradient is to start falling south with 20-25 kt north winds off Pt Arena and 15 kt north winds pushing nearshore for Central CA.   Southern CA to remain under a light wind flow for the duration.


South Pacific

Jetstream  -  On Thursday (8/15) the jet was well .cgiit over the Southwest Pacific then merged over the Southeast Pacific. Winds remained weak over the length of the influential southern branch only reaching 120 kt in one small pocket pushing north up to the merge point forming a bit of a trough there on the extreme eastern edge of the California swell window. Minimal support for gale development there.  Otherwise a ridge was pushing the southern branch hard south in the West Pacific down to the Antarctic coast. Over the next 72 hours the same basic pattern is forecast with a .cgiit jet and ridge in control south of New Zealand pushing the southern branch into the Ross Ice Shelf eliminating support for gale development there. The trough in the far east is to continue, with winds not exceeding 100 kts into Mon (8/19) offering no real support for gale development. Beyond 72 hours the same pattern is to hold with the southern branch ridging south under New Zealand pushing into the Ross Ice Shelf and then troughing north over the Southeast Pacific with a small pocket of 110 kt winds tracking north there late on Tues (8/20) providing bare minimal support for low pressure development. Basically there's no signs of anything but a lockdown on support for gale development over the greater South Pacific.  

Surface  - On Tuesday (8/13) no swell producing fetch of interest was occurring. Weak low pressure continued circulating in the far Southeast Pacific starting to generate 30 kt south winds on the eastern edge of the Southern CA swell window and expected to hold through Friday and building to near 30 kts. Seas to build to 24 ft over a tiny area Friday (8/16) at 53S 124W aimed north.  Maybe swell of 1-2 ft @ 14 secs to reach Southern CA with luck. Otherwise a.cgiacid weather patten remained in control. Over the next 72 hrs another weak low to build over the Southeast Pacific generating south winds to 30 kts but no seas even reaching 20 ft are forecast. And high pressure is to be building east of New Zealand at 1028 mbs on Sunday 98/18) continuing the lockdown. In short, no swell producing fetch of interest is forecast.  

Previously a gale developed in the far Southeast Pacific on Tues AM (8/13) producing 40 kt south to southwest west winds aimed barely at Southern CA and better at Chile with 28 ft seas over a tiny area at 58S 120W then quickly raced east by evening with seas to 29 ft at 54S 113W totally east of even the Southern CA swell window. Maybe a dribble of swell to radiate north towards CA. By Wednesday (8/14) this system developed more with seas exceeding 30 ft but all energy targeted Chile and well east of the California swell window. 

Southern CA: Minimal swell arriving late Tues (8/21) building to 1.3 ft @ 18 secs (2.0-2.5 ft) building to 1.6 ft @ 16 secs (2.5 ft) on Wed (8/22). Swell Direction: 175-180 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 low pressure tracking through the Northern Gulf is to be inland over Canada by Monday AM (8/19) with any windswell producing fetch dissipating.

Relative to California high pressure is forecast building a little more into the north end of the state Monday with the gradient building with north winds to near 30 kts holding into Tuesday (8/20).  The result is to be marginally larger north windswell down into North and Central CA. The gradient to to start fading Wednesday but still holding in the 20-25 kts range then possibly rebuilding some Thurs (8/22). Windswell production continuing. 

Relative to Hawaii weak high pressure is to push east of the Islands by Sun (8/18) with trades fading to 15 kts and then falling below the critical 15 kt threshold on Monday with windswell dropping out. No return of solid trades forecast through the end of the workweek.

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 (8/15) the daily Southern Oscillation Index (SOI) was down to -1.70. The 30 day average was down to 6.01 with the 90 day average down some at 8.21. The nearterm trend is towards a weak Active Phase of the MJO while overall the pattern was 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 weak east wind anomalies over the Eastern Maritime Continent fading to neutral if not barely westerly over the dateline and continuing south of Hawaii. Neutral anomalies extended from there into the coast of Central America. A week from now (8/23) neutral anomalies are forecast taking over the Maritime Continent continuing over the dateline region and to a point south of Hawaii. Neutral anomalies are forecast on into Central America. In all this suggests a neutral phase of the MJO if not almost slightly Active.    

The longer range models (dynamic and statistical) run on 8/14 are in general agreement. Both models suggests no MJO activity was occurring with a neutral pattern over the West Pacific. No change is forecast for the next 15 days per the statistical model while the dynamic model hold tight hinting at weak indications of the Inactive Phase building while tracking east off the Philippines 5-15 days out. This tendency has built in the latest run of the model. The ultra long range upper level model favors formation of some flavor of weak Inactive Phase of the MJO from 8/20 through 9/4, then falling back towards a neutral pattern for the remainder of September. But overall no coherent MJO signal is expected. 

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 (8/15) a very weak La Nina-like pattern continues in the East Pacific on the equator. If anything the small pocket of cooler water we've been monitoring off the immediate coast of Peru is starting to pulse again, with the outflow from it tracking to the Galapagos if not west of there, then breaking up with pockets of cooler water radiating west almost to a point south of Hawaii. Imagery from 8/5 to present  suggest the cool pool has been re-generating, and the 8/15 image is the coolest yet. 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 gaining some ground too with a faint cool flow building and becoming more distinct reaching again almost to South America. 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.  As of 8/12 into 8/15 is appears to be rebuilding off the California coast with a 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, so it's anyone guess whether the local pool will get mowed over by the eastward moving warm pool. For now cooler waters over the equatorial East Pacific are under control, but still present, with no sign of a warm pattern developing. In short, we're still under some weak influence of La Nina or at least a neutral pattern biased cold.  

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 8/15 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 slow warming trend (up to +0.25 degs C) by Nov 2013 and near +0.6 C by April 2014. 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 recharge 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 kinda 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 for 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 high pressure is to build over the Southwestern Pacific to 1032 mbs by Tues (8/20) locking down storm production there and holding through the end of the workweek. A weak pressure pattern is to continue in the Southeast Pacific typical of the late stages of winter in the Southern Hemi with 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:

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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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