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Pacific Storm and Surf Forecast
Updated: April 30, 2011 1:02 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 = 1.75 - California & 2.0 - 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 5/2 thru Sun 5/8
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   

Weak North Pacific Gale Tries to Organize
Small Gale also Trying in the Southern Hemi Too


New Swell Classification Guidelines (Winter)

Significant: Winter - Swell 8 ft @ 14 secs or greater (11+ ft faces) for 8+ hours (greater than double overhead). Summer - 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: Winter - Swell and period combination generating faces at head high to 1.5 times overhead (4-7 ft). Summer - 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. Summer - up to waist high swell. Also called 'Background' swell.


Current Conditions
On Saturday (4/30) North and Central California was seeing locally generated windswell at shoulder to head high and warbled if not chopped. Southern California was seeing locally generated northerly windswell at thigh high and semi-clean early, but still warbled.  Down south northerly windswell was the all so the only surf source with waves maybe waist high up north and reasonably clean. Down south waves were waist to maybe chest high at top spots and reasonably clean. Hawaii's North Shore was flat and clean with modest trades in effect. The East Shore was minimal northeast windswell at waist high and lightly chopped. The South Shore was getting bare minimal southern hemi swell with waves thigh to maybe waist high and clean with light trades.  

Surf Forecast Overview
North and Central CA on Sunday (5/1) is to see
fading windswell at 4.5 ft (faces). Monday things fade out yet more with windswell 2.0 ft rising only slightly Tuesday to 3 ft.  Wednesday semi real windswell returns at 6 ft then dropping Thursday from 5.5 ft.
Southern California is to see local northerly windswell fading from thigh high on Sunday. Monday maybe knee high northwest windswell will be lapping in fading to flat on Tuesday. Wednesday new north windswell arrives at thigh high fading to knee to thigh high on Thursday.
The North Shore of Oahu is to see new northwest windswell arriving Sunday at waist high fading from knee high early Monday and then going flat. Wednesday possible new dateline swell arrives at shoulder high late pushing 1-2 ft overhead on Thursday.  
The East Shore is to see east windswell at knee high Sunday building to waist high Monday and waist to chest high Tuesday. Windswell continue up Wednesday to near head high and holding into Thursday.
The South Shore is to see knee to thigh high background southern hemi Sunday then fading to flat Monday and holding there. Maybe Thursday new swell arrives to near chest high.

Meteorological Overview
The North Pacific forecast remains minimal with only one low of interest forecast for the Dateline on Sunday AM (5/1) with 23 ft seas and holding there for 24 hours before dissipating and starting to push east. Some decent northwest swell possible for Hawaii by late Wednesday with even remnants reaching the US West Coast late week if all goes down as forecast. Down south a gale is developing in the Central Pacific Fri-Sat (4/30) but falling southeast, with seas only forecast to 26 ft at best and getting little traction pushing north. A second incarnation of this system is forecast for late Monday in the East Pacific generating barely 30 ft seas and aimed better to the north, but that will likely turn out to be something less as we get closer to that date. Nothing else to follow with high pressure taking control east of New Zealand.  


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

North Pacific

On Saturday (4/30) the jetstream was tracking off the Southern Kuril Islands with a small trough developing just east of there fed by 150 kt winds feeding into it. Some support for gale development there. A ridge was in.cgiace over the dateline dropping into a weak trough in the Western Gulf of Alaska , then ridging again while pushing into the Pacific Northwest. No support for gale or even hardly low pressure development indicated other than the trough off the Kurils. Over the next 72 hours the Kuril trough is to move fast east to the dateline by Sunday (5/1) with winds still 130 kts and holding into early Monday, then weakening fast and tracking off to the east. Limited support for low pressure development in this trough. Beyond 72 hours another pocket of wind energy is forecast pushing off the Kuril's with winds 150 kts on Tues (5/3) but no trough is forecast forming. It is to spread east across the length of the jet by Friday (5/6) pushing into Vancouver Island, but again no trough or support for low pressure development is indicated. Still, it is not .cgiit or doing anything that would signal a total shutdown of low pressure development just yet.

At the surface on Saturday (4/30) high pressure at 1036 mbs was ridging into Oregon and Washington setting up a pressure gradient over all of North and Central CA and generating north winds at 20-25 kts along the coast. This was resulting in some degree of local windswell. Otherwise a new gale was forming just west of the dateline with winds pushing 35+ kts in it's southwest quadrant aimed at Hawaii. Pretty nice looking for the moment. Over the next 72 hours high pressure off the US West Coast is to evaporate on Sunday with winds all but gone late in the day. Windswell generation potential fading out.  But the gale on the dateline is to actually build Saturday evening with up to 40 kt northwest winds at 43N 175E (317 degs HI) with seas on the increase. By Sunday AM though the gale is to be starting to fade, with a moderate fetch of 35 kt west winds at 45N 180W generating 22-23 ft seas at about the same locale pushing down the 328 degree path to Hawaii and the 300 degree path to NCal. 35 kt westerly fetch is to hold into the evening at 45N 178E resulting in more 23 ft seas at 45N 179E pushing to both HI and NCal as specified before. Fetch to be fading from 30 kts at the same location Monday AM (5/2) with seas dropping from 23 ft at 43N 180W. 18 ft residuals left by evening. Assuming all goes as forecast some degree of small semi swell with period in the 13 sec range is possible for Hawaii by late Wednesday (5/4) and the US West Coast maybe 2 days beyond. At least it's something to monitor.

Otherwise a very local gale is forecast forming off Vancouver Island on Monday (5/2) generating 18 ft seas and local raw windswell there for Tuesday.    


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


No tropical systems of interest were being tracked.

California Nearshore Forecast
On Saturday AM (4/30) high pressure at 1032 mbs was in control centered 500 nmiles west of Oregon and ridging hard into the coast there up into Washington and generating solid pressure gradient and northwest winds at 25 kts over the North and Central CA coasts and outer waters of Southern CA.  These winds are to starting settling down Sunday and dropping below 15 kts by afternoon while low pressure moves into the Eastern Gulf of Alaska. Weak high pressure is to try and hold on well off the CA coast Monday with a 15 kt flow forecast then the high is to push east on Tuesday with the wind machine on the increase again. 25-30 kt north winds are forecast over outer waters off Cape Mendocino holding into Wednesday with a light eddy flow expected for Southern CA and maybe even up into Central CA from San Francisco southward. Thursday the gradient is to start fading, but not out then falling south with 20 kts winds pretty much taking control of Central CA nearshore waters later Friday (5/6). More winds fore the weekend too. It's Spingtime during a La Nina year, so what else can one expect. We got luck in that the wind held off as long as they did.


South Pacific

Currently high pressure at 1028 mbs was positioned over New Zealand, shutting down gale production there. But to the east a gap in high pressure was allowing a small area of low pressure to build well south of Tahiti. That low resulted in a moderate fetch of 40 kt south winds Friday AM (4/29) at 52S 157W aimed well to the north. Unfortunately the core of the low was falling southeast fast though and by evening only 30 kt south winds held at 51S 155W. 25 ft seas were modeled at 50S 153W. On Saturday AM (4/30) a tiny core of 40-45 kt south winds developed at 55S 145W aimed well to the north but the whole low was continuing to fall southeast, with 25 ft seas hanging on at 49S 152W. By evening all fetch is to wrapping into the gales north quadrant aimed east and down to 35 kts and the core is to be falling south fast. Sea forecast to 28 ft over a tiny area at 52S 141W aimed due east. Sunday AM this system is to be gone. At this time some minimal background southern hemi swell seems possible for the US West Coast with sideband swell pushing into Hawaii. Will monitor.  


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 hrs the models suggest another low is to track from the Kuril Island east towards the dateline Tues-Wed (5/4) with 30-35 kt west winds and 20-22 ft seas being produced. Maybe some windswell potential for Hawaii with luck.  

As of Saturday (4/30) the Southern Oscillation Index (SOI) continued relatively low, but nothing noteworthy. The daily SOI was at 10.60. The 30 day average was down slightly at 23.86 with the 90 day average down slightly at 21.27.  

Wind anomalies as of Friday (4/29) at the 850 mb level (approx 5000 ft up) as defined by models indicated weak easterly anomalies in control over the entire equatorial Pacific almost reaching Central America and indicative of the Inactive Phase of the MJO. These anomalies are to start pushing into Central America on 5/4 then rapidly degenerate, with remnants fading over Central America by 5/9. This is expected to suppress gale development. At this time the Active Phase of the MJO was building in the Indian Ocean and expected to start pushing into the West Pacific on 5/9 maybe reaching the dateline by 5/14, then fading there though 5/19, hopefully increasing the odds for storm production in the Pacific.  

Sea Surface Temp anomaly data (4/28) is unchanged and continues to indicate that cooler waters (-1 C degs) had a grip on the equator covering from a a good bit west of South America westward to the dateline. Cooler than normal waters also were present in feeder bands originating off the US West Coast (not as strong as earlier in the Winter) and somewhat colder ones off South America sweeping fully to the intersection of the dateline and the equator, serving to continue the existing La Nina pattern. These colder waters are a reflection of stronger than normal high pressure built in over both hemispheres causing upwelling in the Gulf of Alaska and off South America, though it looks like the upwelling effect was stronger in the southern hemi than in the north. But the cooler waters in the North Pacific are relenting some as are the cool temps over the equator. Warmer than normal waters remain over the Galapagos Islands and over a very narrow band west of there and slowly building in coverage. And tongues of warmer water are positioned in the both the Northwest and Southwest Hemispheres trying to make inroads to the east. Regardless, the big picture still looks like a La Nina setup (though fading in intensity). 

Below the surface on the equator there had previously been indications of Kevin Wave activity.  Colder than normal water that had been locked all winter southeast of Hawaii under the equator evaporated in late February and moved to dead neutral presumably from the effects of two consecutive bouts of the Active Phase of the MJO which in turn might have driven a Kelvin Wave. In parallel warmer than normal water had edged east from the West Pacific, previously up +2 degrees above normal and positioned due south of Hawaii (150W) under the equator through 3/22. But there had also been an impenetrable wall at 140W separating the warm anomalies, and cool anomalies east of there that was blocking any eastward progress of warmer subsurface water. But on 4/4, it appeared that that wall was fading if not gone entirely (by 4/7).  And currently (4/19) a small but steady finger of normal to slightly warmer (0 to +1 deg C) water was flowing east making it to the equatorial East Pacific up at 100-150 meters and building some.  Almost +1 degrees anomalies are tracking from the West Pacific to the East Pacific short of one small break at 160W. It would be best to see warm anomalies down to 200 meters, but the current state is the best it's been in 9 months and suggestive of a near normal subsurface thermocline.  The thought is this normalization of the subsurface flow will eventually affect water temps at the surface and then the atmosphere above it (6 months later).  So all this is a step in the right direction though painstakingly slow.  

Over the entire Equatorial Pacific trades were blowing all the way to the Philippines and beyond. From a historical perspective these easterly winds were 'normal' with only light easterly anomalies persisting in the far Western Pacific.  

Remnants of what was a moderate.cgius strength La Nina Pattern (where the Inactive Phase takes control) are still evident and momentum from this La Nina event are expected to hold well into the Fall of 2011 (and likely to early 2012) in the upper atmosphere regardless of how quickly La Nina's demise occurs in the ocean. In short, it's going to be tough for surfers on west facing shores in the Eastern Pacific and Eastern Atlantic, though east facing shores of the West Pacific and Atlantic might do well from the Inactive Phase's dominance, especially in summer months.  That is not to say there will be no storms, in fact, there could be short periods of intense activity when the Active Phase gets an opportunity to come to fruition, but that will be the exception rather than the rule, with the Inactive Phase trying to keep a cap on storm activity. Best bet's at this time are for an enhanced tropical season in the Atlantic (2011).  

See more details in the   El Nino update.


South Pacific

Beyond 72 hours another small gale is forecast forming from the remnants of the previous gale in the Central Pacific with 40 kt south fetch forecast Sunday AM (5/1) at 50S 155W aimed due north with seas on the increase. By evening maybe 40 kt south winds to persist at 47S 145W with seas building to 24 ft at 45S 151W. Monday AM (5/2) more fetch is to build with 45 kt south winds forecast over a tiny area at 50S 140W pushing up the 192 degree path to CA (unshadowed by Tahiti) but a bit east of Hawaii. 24 ft seas forecast at 48S 140W. 45 kt south winds to hold in the evening at 50S 140W with near 30 ft seas forecast at 49S 140W aimed well to the north. A rapid fade is forecast by Tuesday AM (5/3) with no swell producing fetch remaining. Maybe some modest swell to radiate north towards California with sideband swell towards Hawaii, but its' still a bit early to expect much.

Beyond that high pressure at 1032 mbs is to be migrating east from New Zealand pretty much locking the entire Central Pacific down and suppressing gale development through the upcoming weekend.

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

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: 

Mavericks Surf Shop Grand OpeningSunday, December 19 2:00 - 6:00 p.m. rain or shine!  Check out the new home of Jeff Clark's Mavericks Surf Shop, now located at 25 Johnson Pier in Pillar Point Harbor.  The shop features much of Clark's surfing memorabilia, classic boards and photos, as well as an entirely new line of Jeff Clark original Mavericks clothing, accessories and surfboards. The shop has been open in the new location since December 8, and the Grand Opening party is set for this coming Sunday, just in time for Christmas.  The party starts at 2 p.m., with live music, food and drinks. Jeff Clark and many Mavericks surfers will be there to meet the public. Local restaurants Ketch Joanne's and Princeton Seafood will serve up delicious food, while San Francisco Wine Trading Company is providing the beverages.  The shop will be open all weekend, from 9 a.m. to 8 p.m. on Saturday and Sunday.

Stormsurf Maintenance Upgrades: Buoy 46059 and 46012 were r.cgiaced a month or so ago. Totally new buoys were installed. Here on Stormsurf we had to reset the algorithms used to calculate 'pure swell' for them. That was acco.cgiished on 11/13. Pure swell numbers are now correct. Links: 46012, 46059

Also since we moved to the new weather model server last month we discovered that our Longrange Precipitation Models ceased to display frozen precipitation (as they once did). Some of our scripts did not get installed on the new server. That has been fixed (11/13) and now snow is again viewable worldwide. Here the new North America sa.cgie.

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.   

Click here to learn more about Casa Noble Tequila! Casa Noble Tequila If you are looking for an exquisite experience in fine tequila tasting, one we highly recommend, try Case Noble. Consistently rated the best tequila when compared to any other. Available at BevMo (in California). Read more here:

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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