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Pacific Storm and Surf Forecast
Updated: December 18, 2012 9:56 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 = 4.1 - California & 1.5 - 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 12/17 thru Sun 12/23
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   

Storm Brewing the Gulf
.cgiit Jetstream To Continue But More Energy Possible for the West

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.

Merry Christmas and Happy New Year!  
We just want to thank you for continuing to support Stormsurf and the folks who advertise with us.  It's been a good year and we have new project and new content in development and coming your way. We hope you have a great holiday and get some waves, or fresh tracks!  Forecasts will be sporadic over the next 2-3 weeks while we try and have a little fun ourselves. Again, thank you and have a happy and safe holiday!   

Current Conditions
On Tuesday
(12/18) North and Central CA had local gale induced north angled swell arriving producing waves in the 10+ ft range and hacked by strong north winds. It was unrideable. Down south in Santa Cruz waves were head high or so and hacked by strong wrap around westerly winds. Southern California up north was knee high and blown out. Down south waves were knee to thigh high and blown out with northwest wind in control. Hawaii's North Shore was getting minimal sideband Gulf windswell with waves chest high and pretty wonky with trades blowing firmly.  The South Shore was flat. The East Shore was getting solid east tradewind windswell at 1-2 ft overhead and chopped.  

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

Meteorological Overview
A pair of weak local gales developed off the Pacific Northwest Monday and Tuesday generating 24 ft seas and pushing swell down the California coast Tuesday and again for Wednesday. But of more interest is a storm forecast for the Northern Gulf of Alaska Wed-Thurs (12/20) producing up to 40 ft seas. North angled swell is forecast for the US West Coast for the weekend but mostly encased in rain and wind north of Pt Conception. Sideband energy for Hawaii. And yet another system is forecast behind on Tues-Wed (12/26) again positioned in the Northeastern Gulf with another behind that forming in the far West Pacific. It looks like the storm pattern is finally starting to improve. 


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

North Pacific

Jetstream - On Tuesday (12/18) an invigorated flow was developing over Japan with winds 170 kts, inching offshore and quickly .cgiitting with the northern branch heading up into the Bering Sea, then falling southeast building into a trough while moving through the Central Gulf of Alaska with winds to 150 kts.  Improving support for gale development in the Gulf.  Over the next 72 hours the Gulf trough is to deepen with 140-150 kt winds pushing through it and continuing to feed gale development potential in the Gulf through Saturday (12/22), then it is to move onshore. Beyond 72 hours winds to start building off Japan to 190 kts pushing northeast with the .cgiit point moving to the dateline if not a bit east of there. A broad trough is to possibly take shape in the Northwest Pacific off Kamchatka, possibly supporting gale development, while a ridge builds over the Gulf of Alaska and a calm pattern prevails.  

Surface Analysis  -  On Tuesday (12/18) swell associated with a weak gale that tracked from the dateline into Oregon was hitting CA.It's to be fading out by Wed AM (12/19).   A second weak local gale formed in it's wake in the Northern Gulf generating 24 ft seas Monday evening at 49N 139W targeting Oregon and California. Swell of 7-8 ft @ 14 secs (10 ft) possible by late Wednesday (12/19) from 315+ degrees for North CA. High pressure at 1036 mbs was trying to hold ground between the Gulf and Hawaii but was under increased pressure from a building gale in the Northern Gulf (see Second Gulf Gale below). Over the next 72 hours all eyes are to be one the Second Gulf Gale, not so much because it's greatly positioned or particularly strong (which it isn't) but because it's the only game in town. 

Second Gulf Gale
A gale developed west of the dateline Sunday AM (12/16) with 40 kt west winds and seas building. Winds held at 40 kts in the evening as the gale raced east-northeast generating 28 ft seas at 41N 160E (299 degs NCal, 310 degs HI). 35-40 kt southwest winds held into Monday AM (12/17) as the gale reached the intersection of the dateline and the Aleutians with 24 ft seas lagging behind over a modest area at 43N 170E (301 degs NCal, 316 degs HI). Winds  held at 35-40 kts in the evening just barely clear of the Eastern Aleutians with seas 23 ft at 50N 170W targeting only the US West Coast (305 degs NCal). This system held in the Northern Gulf on Tuesday AM (12/18) with 40-45 kt northwest winds building and seas regenerating to 26 ft initially at 52N 158W (310 degs NCal). A decent area of 50 kt northwest winds are to take hold in the evening in the Northern Gulf with seas 32 ft at 53N 150W (312 degs NCal). Winds to hold Wednesday AM (12/19) at 45-50 kts and with 35+ kt+ winds building southeast into the Central Gulf with seas 37 ft at 50N 147W (314 degs NCal). The gale is to start falling southeast in the evening with a solid area of 45-50 kt northwest winds in the core of the Gulf and 36 ft seas at 46N 146W (304 degs NCal). The gale to continue southeast on Thursday AM (12/20) with 40-45 kt northwest winds positioned well off Oregon targeting primarily California with seas 39 ft at 46N 143W (306 degs NCal). Residual 30-35 kt northwest fetch to be fading in the evening off Cape Mendocino with 30 ft seas at 42N 135W (304 degs NCal). This system to be gone by Friday. 

This system has potential to generate relatively local longer period swell targeting the entire US West Coast.

North California: Rough data suggest swell arrival on Thursday at 8 PM and building starting to get solid Friday 7 AM (12/21)  with period 17 secs and size on the increase through the day.  Swell peaking near 4 PM at 11.25-12.3 ft @ 17-18 secs (19.1-22.1 ft).  Hard south winds and miserable conditions forecast. Swell Direction: 304-306 degrees 

Southern California: Rough data suggest swell arrival on Friday 2 AM (12/21) with period 17 secs and size on the increase steadily through the day on into the evening, peaking near 4 AM Saturday (12/22) at 11.2 ft @ 17-18 secs (19.1-20.0 ft outside the Channel Islands).  Swell nearshore 5.3 ft @ 17-18 secs (9 ft) nearshore and maybe a little bigger in San Diego. Swell Direction: 306-310 degrees 


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


No tropical systems of interest are occurring.   

California Nearshore Forecast
On Tuesday (12/18) high pressure at 1038 mbs was trying to ridge into the California coast as low pressure exited the region to the east. This was resulting in a pressure gradient producing north winds at 20 kts raking the entire California coast. The low produced about 16 inches of snow for the Tahoe region through this morning. Wednesday a stronger front builds in the Gulf while north winds clear out of CA. A light winds flow forecast locally though south winds and rain to build late in the north. Thursday the front to push down to Moneterey with south winds 20+ kts the rule. The rain line to start just north of San Francisco pushing to Monterey Bay late. Snow starting for Tahoe with another 5 inches of accumulation possible overnight. Friday more of the same forecast with south winds 20 kt and rain the rule from Pt Conception northward.  10 inches of snow for Tahoe. Saturday winds turn westerly at 15 kts from Monterey Bay northward.  Rain building down to Santa Barbara. 2 ft of snow for Tahoe. Then wind turns south on Sunday as one last pocket of low pressure energy move into and over the San Francisco Bay area. South winds down to Pt Conception. Rain sweeping south to Santa Barbara late. another foot of snow for Tahoe.  Low snow levels.  Monday high pressure takes control with rain exiting south over Southern CA and north winds blowing over the entire state, continuing Tuesday.   


South Pacific

Surface  -  No swell producing weather systems were occurring.  Over the next 72 hours no change is forecast.  


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 the models are suggesting another gale trying to develop in the extreme Northeastern Gulf on Tues (12/25).  Seas forecast in the 24 ft range perhaps offering some north angled swell from Pt Conception northward.  And in the West a broad but unorganized gale is forecast trying to organize west of the dateline off Kamchatka. The fetch area is to not be well organized.  Regardless, both systems are worth monitoring.  

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 (12/18) the daily Southern Oscillation Index (SOI) was up down again at -21.64 (12 days in double digit negative numbers) due to localized low pressure over Tahiti and not necessarily a direct El Nino or MJO symptom. The interesting thing about this scenario is that the low is to hold steady over Tahiti through Fri (12/21). The 30 day average was down to -7.90 with the 90 day average down some at -0.42. This is neutral territory and not indicative of El Nino. 

Current equatorial wind analysis indicated light east anomalies over the Western Maritime Continent (WPac) giving way to light west anomalies over the Eastern Maritime Continent then turning to light west anomalies over the dateline continuing in pockets alternating between east and west all the way to Central America. A week from now (12/26) and area of modest east anomalies are forecast over the dateline but confined to a small area and then neutral on into South America. This suggests a continuation of neutral MJO pattern over the Pacific.  

The longer range models (dynamic and statistical) run on 12/17 suggest a modest Inactive Phase was in.cgiay over the Pacific with a pocket of above normal precipitation south of Hawaii. The Active Phase of the MJO was in the Indian Ocean. Both models are now in agreement indicating the Inactive Phase is to slowly fade while easing east through the next 2 weeks migrating to the dateline or a bit east of there while the Active Phase builds in the Indian Ocean trying to ease east. This pattern supports a continued .cgiit jetstream and offering no real catalyst for gale development over the coveted dateline region. 

Given the demise of what was almost an El Nino pattern earlier in the year, we believed a return to a normal MJO cycle was occurring with the Inactive and Active Phases becoming more pronounced and regular. But the collapse/stalling of the MJO in November and December renders that projection false. As of now (12/15) it seems the MJO is dead or weakly Inactive. And the jetstream flow aloft is symptomatic of that MJO situation, rather weak and ineffective. At a minimum a .cgiit jet suggests a very weak wind flow aloft. If any flavor of El Nino or an Active Phase was in.cgiay, the jet would not be .cgiit. At this point in the season we're now thinking on significantly downgrading the long range outlook, being that it appears we're in a dead neutral pattern and no energy pushing the global weather pattern in any direction. This would result in a long term pattern of depressed levels of storm potential. 

The more warm water in the equatorial East Pacific means more storm production in the North Pacific during winter months (roughly speaking). A weak Kelvin Wave propagated east erupting along the Central American coast late October and initially we thought it did little to r.cgienish the warm water pool, only holding it at a steady state. Some data suggested a slightly strong impact, but nothing remarkable. A second Kelvin wave developed due to a prolonged WWB event in the West Pacific between Sept 2 and Oct 9. That Kelvin Wave had 2-3 deg C warmer than normal subsurface water and was located in pockets under the equator. It has reached the Central America coast and has provided a little boost to water temps, but nothing dramatic.  At a minimum it should keep things in the normal range. Water temps off Ecuador have returned to normal of even slightly warmer as of 12/13.  

And what initially appeared to be a strengthening MJO pattern (both Active and Inactive Phases) suggested a return to a neutral ENSO pattern. But that has collapsed (see above). That said, projections from the CFSv2 model are not supporting any form of El Nino development but almost a return to La Nina with -0.5 deg C water temps by late January into February, then slowly returning to normal if not slightly warmer by June 2013. But virtually all the other ENSO models predict a slow decline from El Nino threshold temps into Spring 2013, but never dipping into negative territory.  The CFSv2 model is a minority opinion, if not a complete outlier. This is a bit better than hoped for and still gives us a glimmer of hope for a normal Winter in terms of storm production. But looking at the atmosphere, there's no overt signs of anything remotely resembling El Nino, and if anything, with a .cgiit jetstream pattern over the North Pacific, it looks still like some vestiges of La Nina.  So the warm spurt in July 2012 was just a false start.     

It appears we are in a dead neutral ENSO pattern with neither El Nino or La Nina imminent.  But that is a far better.cgiace than the previous 2 years under the direct influence of La Nina. Based on current data the outcome for this Winter is not looking good. We had expected a normal number of storms and swell, but the total lack of any real activity so far is going to make us downgrade that projection. A complete lack of  ENSO energy typically signals a lack of storm energy, and is perhaps a harbinger of the coming 5 months. Longer term the expectation is this winter will be followed by at least one year of slightly warmer temps (2013) ultimately converging in a stronger warmer pattern and possible El Nino 2-3 years out (2014 or 2015). 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 Finally updated 10/6/12 


South Pacific

Beyond 72 hours 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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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:

Steve Colleta Surfboards - Check out surfboards by local shaper Steve Coletta - A long time Santa Cruz local and master shaper. Progressive shapes for North and Central CA waves

Chasing the Swell has been nominated for a Webby Award. See details of this great piece of video journalism below. Some say this is the "Oscars" of online awards.One of the awards is voter based. If you have a moment,.cgiease cast your ballot by going to:, register, then click on the "Get Voting" tab and then to the "Online Film and Video" > "Sports" category and vote for "Chasing the Swell".

Timmy Reyes - Curt Myers from Powerlines Productions found this little gem with Timmy Reyes providing a brief statement about which sites he uses for swell chasing. Thought we'd pass it on. Enjoy:

Buell Wetsuits - When surfing in Santa Cruz, we've been seeing a new wetsuit in the line-up worn by many top flight surfers. They're getting good traction and are well respected. Take a look:

Stormsurf Mobile App (1/9/11) We are proud to announce the official public release of our smartphone mobile app. It provides access to our most popular and commonly used products, optimized for use on the road, on the beach or anywhere you don't have a desktop or laptop.  With a smart phone and signal, you will have access to our data. And we're not talking just a few teaser products - We're talking full feature wave models, weather models, real-time buoy data, manually built forecasts and hundreds of spot wave and wind forecasts enabling you to construct a surf forecast for any location on the.cgianet, all from your cell phone and all for free.  No subscription required and no hidden fees. And better yet, there's a few new things sprinkled in that are not yet available even on our full-featured web site. From your smart phones browser just navigate to: 

Chasing The Swell: Sachi Cunningham from the LA Times spent the entirety of last winter chasing surfers and swells around the North Pacific with her high def video cam. Her timing couldn't have been any better with the project exactly coinciding with the strongest El Nino in 12 years resulting in the best big wave season in a decade. And being an acco.cgiished surfer herself helped her to bring a poignant and accurate account of the what it's like to ride big waves and the new (and some not so new) personalities that are revitalizing the sport. This is must-see material for any surfer or weather enthusiast. Check it out here:

New Weather Models With the activation of our new server we have now released a new block of weather models including North America jetstream, wind and precipitation, local coastal wind forecasts in 1 hr increments and snow and mountain wind forecasts in both 1 and 3 hours increments. The new animations can be found here (look for those items tagged with the New! icon):

New Weather Model Server Stormsurf has installed another weather model production server. This has enabled us to spread the load across more servers allowing us to post both wave and weather model updates much quicker.  Also we are testing new content (like North America jetstream, winds and precipitation, local wind forecasts in 1 hr increments and snow and mountain wind forecasts in both 1 and 3 hours increments). The model menus will be updated shortly with these new 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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