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Pacific Storm and Surf Forecast
Updated: April 16, 2013 7:35 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 = 3.0 - California & 0.5 - Hawaii
Using the 'Summer' Scale
(See Swell Category Table link at bottom of page)
Probability for presence of largest swells in near-shore waters of NCal, SCal or Hawaii.    
Issued for Week of Monday 4/15 thru Sun 4/21
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 to Continue For CA
With SPac Swell Underneath - Small NPac Swell For HI Too

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.

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Current Conditions
On Tuesday
(4/16) North and Central CA was seeing local north windswell in control with waves head high to a bit overhead and totally blown out. Whitecaps to the horizon. Down in Santa Cruz waves were thigh to waist high with chest high sets and clean but weak with whitecaps outside the kelp. Southern California up north was thigh high and blown to bits. Down south waves were head high on the sets and ripped apart by northerly winds. Hawaii's North Shore was small with sets in the waist to maybe chest high range and clean. The South Shore was flat. The East Shore was getting east windswell at knee high and lightly textured. 

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

Meteorological Overview
Locally generated north short period windswell to continue for California through the later part of the workweek, then starting to fade with improving conditions. A cut-off low that has been circulating over the dateline pulsed again on Mon-Tues (4/16) producing 18-20 ft seas offering some more weak northwesterly swell for the Islands by later in the workweek. There are hints of another similar event mid-next week too if one is to believe the models. But realistically the North Pacific is quickly moving into it normal summer time hibernation pattern. Swell from a small gale developed in the deep southeast Pacific Sunday AM (4/7) was hitting, but with less size than anticipated and mostly buried under chop. Beyond no clearly defined swell producing weather systems are forecast. Maybe some impulse class swell to be generated, but even that is just a guess with no seas exceeding the 26 ft threshold aimed to the north indicted. A real quiet pattern is expected. Details below...   


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

North Pacific

Jetstream - On Tuesday (4/16) the jetstream was weak and fragmented pushing off Japan with a sliver of energy peeling off tracking northwest back into Siberia while the main flow pushed east if not slightly southeast crossing over the dateline with winds not even 90 kts. A pocket of 130 kt winds appeared just east of the dateline in the bottom of what appeared to be a weak trough there, then the jet .cgiit with 50% of the winds energy tracking up into the Gulf of Alaska moving inland over British Columbia then falling down the US West Coast and the rest tracking southwest of Hawaii and eventually into Baja.  Wind did not exceed 80 kts in either branch.  Minimal support for low pressure development was possible in the trough just east of the dateline.  Over the next 72 hours the jet is to ridge pretty firmly north from Japan reaching up to Kamchatka then falling into the same old weak trough just east of the dateline with winds not exceeding 100 kts.  No real support for even low pressure development indicated.  Beyond 72 hours the trough just east of the dateline is to develop some Sat (4/20) with 110 kt winds falling down into it and getting steeper, almost pinching off north of Hawaii 24 hours and lifting hard northeast with remnants in the Gulf of Alaska late Tuesday (4/23) pinched and with no real wind energy pushing into it.  Limited support for low pressure development possible. 

Surface Analysis  -  On Tuesday (4/18) another pulse of small weak swell was pushing towards Hawaii thanks to a cutoff low previously on the dateline. On Sunday evening a small fetch of 35 kt northwest winds generated 19 ft seas at 44N 172E targeting Hawaii. The fetch fell southeast Monday AM (4/15) with a marginally larger area of 20 ft seas at 42N 172E. By evening the fetch was fading from barely 30 kts with 18 ft seas fading at 37N 177E. Residual 18 ft seas were trying to hang on Tues AM (4/16) at 36N 177W. Some degree of small windswell is expected to push into Oahu arriving Thursday (4/18) peaking at 5 ft @ 13 secs (6.5 ft) fading Fri AM from 4.2 ft @ 12 secs (5 ft). Swell Direction: 315 degrees

Otherwise high pressure at 1036 mbs was centered 600 nmiles west of Cape Mendocino CA resulting in the usual springtime pressure gradient along the North and Central CA coast generating 25-30 kt north winds and ragged local north short period windswell with effects into Southern CA. The gradient to fade some but still be in.cgiace Wednesday over the entire state, then finally relenting Thursday focused mainly on North CA with north winds barely 25 kts over a tiny area there and fading more Friday (see QuikCASTs for surf details). 

Weak low pressure to continue circulating just south of the Aleutians near the dateline slowly easing east reaching the Western Gulf late in the workweek. No swell producing fetch expected to result through.  

Trades relative to Hawaii to build by Wed (4/17) to 15 kts and hold steady over a decent sized fetch into late Friday. Limited short period east windswell possible on east facing shores.

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


No tropical systems of interest are occurring.   

California Nearshore Forecast
On Tuesday (4/16) high pressure at 1034 mbs was firmly in control of waters off California centered 600 nmiles west of Cape Mendocino generating the usual pressure gradient with 25-30 kt north winds pushing down the North and Central California coast, even affecting Southern CA. By Wednesday some relaxation of  local wind is possible but still 15 kts nearshore early and 20-25 kts over outer waters for the entire state. The gradient to finally fade and lift north Thursday with winds over Cape Mendocino 25 kts out of the north but 10 kts or so nearshore from Pt Arena southward and becoming more pronounced by Friday. But by Saturday high pressure to start building some with 25 kt north winds taking root firmly just off all of North CA and 20 kt winds extending down to Pt Conception. More of the same Sunday but with 30 kts north winds near Cape Mendo but much lighter nearshore with perhaps an eddy flow building north to San Francisco. Monday the gradient to fade with an eddy flow (or at least calm winds) in effect for the balance of the state building more so on Tues (4/23). Summer arrives. 


South Pacific

Surface  -  Swell from a storm that built in the deep Southeast Pacific last weekend is hitting the California coast, but with size less than hoped for.  North winds and windswell are making for poor local conditions over the entire state. A small gale developed Sunday evening (4/14) producing a tiny fetch of 35-40 kt south winds in the deep Southeast Pacific aimed almost due north. But by Monday AM (4/15) winds were already fading from 35 kts on the edge of the California swell window resulting in only 26 ft seas at 47S 127W aimed almost due north. By evening winds regenerated to 40 kts seas building to barely 28 ft at 43S 124W again aimed almost due north or up the 180-182 degree path to California. By Tues AM (4/18) this system was all but gone. Limited impulse class swell is possible for Southern CA starting Mon (4/22) with period 18 secs building into Tues (4/23) as period drops to 16 secs early from 182 degrees.     

No other obvious swell producing weather systems are forecast.

Southeast Pacific Storm - Swell 1S
On Sunday (4/7) a storm developed in the deep Southeast Pacific. 55 kt southwest winds were positioned just off Antarctica with seas 42 ft over a tiny area at 65S 137W aimed well up the 187 degree great circle path to SCal. The storm tracked northeast in the evening with southwest winds holding at 50-55 kts resulting in a small area of 43 ft seas at 62S 125W aimed 25 degrees east of the 184 degree great circle path to Southern CA. On Monday AM (4/8) the core of the fetch was east of any clear path to Southern CA but with lingering 40-45 kt southwest fetch still in.cgiay resulting in 38 ft seas at 58S 120W aimed 20 degrees east of the 180 degree path to Southern CA. By evening the gale regenerated with 50 kt south winds just east of the Southern CA swell window and seas 34-36 ft at 55S 115W (178 degs SCal). By Tues AM (4/9) all fetch was clearly east of even the Southern CA swell window. A decent pulse of small significant class southern hemi swell is expected for most of California, favoring the south end of the state and doing better for Central America.

Southern CA: Solid residuals expected continuing Wednesday (4/17) fading from 3.0 ft @ 16 secs early (4.5-5.0 ft). Swell fading Thurs (4/18) from 2.5 ft @ 14-15 secs (3.5 ft). Swell Direction: 178-184 degrees  

Northern CA:  Swell to peak overnight with swell on Wed AM (4/17) still near 3.0 ft @ 16-17 secs (5.0 ft faces with sets to 6.5 ft) but fading through the day down to 2.6 ft @ 16 secs (4 ft). Solid residuals expected continuing Thurs (4/18) with swell dropping from 2.3 ft @ 15 secs (3.5 ft). Remnants left on Friday fading from 1.8 ft @ 14 secs (2.5 ft). Swell Direction: 176-182 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 no real swell producing fetch of interest is forecast.  Theoretically a new low pressure center to develop off Kamchatka on Tues (4/23) generating 35 kt northwest winds and 18 ft seas targeting Hawaii, but that's so far out as to be only a dream at this early date. 

Otherwise high pressure and the local pressure gradient is to surge slightly on Sat-Mon (4/22) generating 25 kt north winds off Cape Mendocino and perhaps generating more short period north windswell for mainly Central CA.  some degree of generally weak low pressure is forecast developing in the Gulf of Alaska next week with luck, but no winds strong enough to generate swell are suggested at this time. 

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 (4/16) the daily Southern Oscillation Index (SOI) was up to 10.81. The 30 day average was up some to 5.60 with the 90 day average up slightly at 2.29. Overall this is neutral territory and not indicative of El Nino. 

Current equatorial wind analysis indicated neutral anomalies over the Maritime Continent and a very weak easterly drift over the dateline region continuing east to a point south of Hawaii. Near neutral anomalies continued east from there into Central America. This indicates the Inactive Phase of the MJO was barely in.cgiay but still present. A week from now (4/24) weak to modest east anomalies are forecast over the Maritime Continent and dateline extending to a point south of Hawaii on the equator, then fading to neutral from there on into Central America. This suggests the Inactive Phase of the MJO is to not be gone just yet.          

The longer range models (dynamic and statistical) run on 4/15 are moving back into alignment.  Initially both suggest a very weak version of the Active Phase of the MJO was on the equator near 150E (Maritime Continent). But by 4 days out the projections diverge with with the statistic model indicating the Active Phase of the MJO building in the West Pacific (centered at 155E) then fading some 8 days out and almost gone on the dateline 15 days out. Conversely the dynamic model suggests the Active Phase is to disperse 4 days out with a dead neutral pattern in control 8 days out holding to at least 15 days into the future. regardless, even the more positive statistic model is suggesting only a very weak Active Phase at best. The likely result is more of the same for the next 2-3 weeks.  This indicates a continuation of a weak MJO cycle and no support from it towards development of even a weak El Nino.

The more warm water in the equatorial East Pacific means more storm production in the North Pacific during winter months (roughly speaking). As of now (4/15) a faint pool of slightly warmer water that was in the equatorial East Pacific, appears to be getting eroded with near neutral water temps off Central America. A tiny.cgiume of markedly cold water continues pushing off the Central American coast to the Galapagos Islands, then dispersing making no western headway. A .cgiume of lightly cooler than normal water continues radiating off the California coast tracking southwest over Hawaii to the equatorial dateline, typical of the effects of a stronger than normal East Pacific high pressure system. But it looks to have less coverage with every update. Suspect it will start growing again with the heavy burst of northerly winds being experienced along California the past 2 weeks. Subsurface waters temps continue indicating a weakening pool of cooler water (-1 deg C) in.cgiace at 125W and down 100 meters, blocking the transport path. In short, temperatures on the surface are not warming and the subsurface path, though not strongly blocked by cooler water) is not doing anything to transport warm water eastward, even if there was warm water to transport. And the coastal pattern off the US mainland suggests somewhat higher pressure and cooler water temps, all signs of a weak La Nina-ish pattern.   

Projections from the CFSv2 model run 4/16 continue improving. They suggest water temps peaked at Nino 3.4 in early April at (+0.6 degs C) and then a slow but steady downhill glide is forecast with temps falling in July to normal (0.1 degs C) and neutral by August, rebounding some in October (+0.2) on into Dec-Jan (+0.3). A consensus of all the other ENSO models suggest near normal water temps into Summer and early Fall 2013 with no warming indicated. We are moving into the Spring unpredictability barrier with accuracy of all the ENSO models historically low. So for now the outcome is uncertain, but not trending towards anything that would be considered warm. Historically, if a warm water buildup indicative of any significant El Nino pattern were to occur, it would be starting to happen by now.  But clearly that is not the case.  

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 (2010-2011 and 2011-2012) under the direct influence of La Nina. We had expected a normal number of storms and swell for the 2012-2013 winter season, but that did not materialize with the pattern looking more like La Nina than anything. This past season was more of a 3 rating than the 5 that was predicted. That said, there was good consistency, with the west dateline area very productive and almost machine-like.  But the storms were very small in areal coverage and rarely made enough eastern headway to even reach over the dateline.  The result was very westerly but reasonably sized utility class swells for the Islands with far smaller and more inconsistent swell energy for the US West Coast.  Longer term the expectation there will be at least one year of neutral to slightly warmer temps (2013-2014) 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 Last Updated 10/6/12 


South Pacific

Beyond 72 hours another small gale is forecast trying to organize under New Zealand on Fri AM (4/19) with 28 ft seas suggested at 55S 178E, then fading Sat AM (4/20) while pushing east. Low odds for impulse class swell targeting Hawaii. 

Nothing else is forecast behind.

Details to follow...


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

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Local Interest

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

The Mavericks Invitational Big Wave Surf Contest is scheduled to air on CBS on Thurs (2/7) at 7 PM (PST) r.cgiaying again on Sunday (2/10) at 7 PM.  Set your DVR.

'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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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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