Surf Forecasts and Marine Weather - No Hype - Just the Facts!
Southern Hemi Swell Hitting CA! - Video Forecast HERE (5/19/24)
Buoys | Buoy Forecast | Bulletins | Models: Wave - Weather - Surf - Altimetry - Snow | Pacific Forecast | QuikCAST | El Nino | Tutorials | Great Circles | Video


Stormsurf Mobile App

Create Your Own Surf Forecast
Swell Calculator
Swell Decay Tables
Sea Height Tables
Swell Category Table
Convert from GMT:
 to timezone:

Pacific Storm and Surf Forecast
Updated: December 16, 2010 10:06 PM
Buoys: Northern CA - Southern CA - Hawaii - Gulf of Alaska - Pacific Northwest
Buoy Forecast:
Northern CA - Southern CA - Hawaii - Gulf of Alaska - Pacific Northwest
Pacific Links:  Atmospheric Models - Buoy Data - Current Weather - Wave Models
Forecast Archives: Enter Here
A chronology of recent Mavericks Underground forecasts. Once you enter, just click on the HTML file forecast you want to review (e.g. 073199.html equals July 31, 1999). To view the maps that correspond to that forecast date, select the html file labeled 073199 maps.html
Swell Potential Rating = 2.6 - California & 2.2 - 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 12/13 thru Sun 12/19
Swell Potential Rating Categories
5 = Good probability for 3 or more days of Significant swell
4 = Good probability for 1-2 days of Significant swell
3 = Good probability for 3 or more days of Intermediate/Advanced swell
2 = Good probability for  1-2 days of
Intermediate/Advanced swell
1 = Good probability for 3 or more days of Impulse or Windswell
0 = Low probability for 1-2 days of Impulse or Windswell   

Gulf of Alaska Storm Track to Improve
Very Wet Weather for California


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.

On Thursday (12/16) North and Central California was getting Gulf windswell at 1-2 ft overhead and clean with cold offshore winds. Southern California was getting  Gulf semi-swell with waves waist to maybe chest high and reasonably clean though a little bit warbled. Down south exposed breaks were waist to near chest high and a little textured but not too bad. Hawaii's North Shore was getting westerly swell from the dateline at head high with bigger sets and clean. The East Shore report was not available. The South Shore is not being monitored for the winter and presumed to be asleep with waves 2 ft or less. 

The forecast for North and Central CA is for windswell fading from 4 ft (faces) on Friday with more raw local windswell arriving Saturday building to 5 ft building to 7.5 ft on Sunday. Windswell builds to 11 ft on Monday from the west and then gone on Tuesday with south windswell to 4.5 ft.  Southern California is to see knee to thigh high leftover northwest swell on Friday continuing with reinforcing swell moving in Saturday but only reaching knee to thigh high, pushing thigh to waist high on Sunday. Monday westerly windswell pushes head high to 1 ft over fading from waist high early Tuesday.  The North Shore of Oahu is to see waist high leftover west swell Friday. Saturday should high north swell starts to build in late with the first of a long run of north swell arriving Sunday pushing 3 ft overhead later and up to 4 ft overhead on Monday and 3 ft over on Tuesday. The East Shore is to see waist high east windswell on Friday and Saturday then fading out. The South Shore is asleep for the winter.

Another gale started building in the northern Gulf Wednesday (12/15) falling south-southeast Thurs-Sat (12/18) with seas in the 23 ft range targeting primarily Hawaii (possible longer run of north swell), then turning east Sat-Sun (12/19) generating 22 ft seas aimed at Central and North CA. Possible small swell for both Hawaii and the US West Coast. A stronger gale is forecast dropping out of the Northern Gulf on Wed/Thurs (12/23) with up to 34 ft seas aimed reasonably well at the US West coast.  But that is still a long ways off. East winds are to continue on the dateline into the middle of next week aimed at Japan driven by the interaction of high pressure just south of the Aleutians and a cutoff low pressure system south of there, and choking off the normal storm track that juts east just south of the Aleutians. But long term things are starting to show signs of improvement. 


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

North Pacific

On Thursday (12/16) the jetstream continued in much the same pattern as weeks past, pushing east off Japan then .cgiitting heavily just off the coast with the northern branch tracking due north up into the Bering Sea then turning hard south falling into the Central Gulf of Alaska and feeding a bit of a semi-permanent trough there, then turning east and tracking up to the CA-Oregon border. The southern branch fell south into a weak trough on the dateline, then ridged slightly and pushed east rejoining the northern branch off the Northern CA coast.  The trough in the Gulf was mildly supportive of gale development with winds up to 150 kts pushing east at it's apex.  The little trough on the dateline was again supporting a weak low pressure cell at the oceans surface and pretty much locked in.cgiace there. Over the next 72 hours the same basic pattern is to hold with the .cgiit over the dateline undulating some but with the two flows rejoining north of Hawaii and flowing at 130 kts into Northern and Central CA by Sat (12/18). A weather/rain & snow event remains likely there. Beyond 72 hours more of the same is forecast but with more energy tracking though the northern branch and spilling eventually into that trough in the Gulf of Alaska by Monday with winds reaching the 130 kt range and holding into Thursday with a steeper trough carving out there, bottoming out about 600 nmiles west of Morro Bay by late Tuesday (12/21) then pushing inland, but with the bulk of the trough still holding off the coast. This trough will likely support gale development with precipitation and winds pushing into the CA coast and some degree of raw swell underneath it all.   But there remains no clear evidence that a healing of the .cgiit jetstream looks likely.  

At the surface on Thursday (12/16) high pressure at 1040 mbs remained locked straddling the Aleutians on the dateline ridging south to a point midway to Hawaii  and blocking the normal eastward progression of low pressure systems pushing off Siberia. Low pressure was in the extreme eastern Gulf of Alaska at 992 mbs producing a fetch of 30 kt north winds extending from Alaska southward aimed at Hawaii and has been in this area since Wednesday (see Gulf Gale below). A weak cutoff low pressure system remained locked over the southern dateline area producing only east winds at 30 kts aimed at Japan. Over the next 72 hours the Gulf Gale is to be of prime focus (see details below). 

Gulf Gale
A broad but diffuse gale started developing in the Northern Gulf of Alaska on Wed (12/15) with 30-35 kt northwest winds up at 50N 155W and holding in that general area through Thursday producing 20-22 ft seas generally at 47N 152W and still in that.cgiace Thursday night aimed well at Hawaii (360 degrees).  The gale is to start falling south on Friday AM (12/17) with more 30-35 kt fetch wrapping into it's southwest quadrant pushing 40 kt late generating 24 ft seas forecast at 42N 152W Sat AM (12/18) aimed a bit east of Hawaii (015 degrees) and at bit south of Central CA (296 degrees).  Still decent north swell is to be pushing towards Hawaii with modest swell starting to take aim on  Central CA.

By Saturday (12/18) the fetch is to turn decidedly east with 30-35 kt northwest winds at 40N 148W with 22 ft seas at 40N 145W still pushing well south of the great circle paths to CA. By Saturday PM residual 30-35 kt west fetch is forecast at 40N 140W with 22 ft seas at 38N 140W pushing towards Central CA (280 degrees) continuing into Sunday AM and nearly impacting the coast then. Limited raw 13 sec period windswell is possible for the Central CA coast if all goes as.cgianned by Sunday AM (12/19) and north swell into Hawaii on Monday (12/20).  


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


No tropical systems of interest were being tracked.

California Nearshore Forecast
On Thursday (12/16) a light offshore flow was in.cgiace but south winds and rain were queued up off the coast.  By Friday AM that is to be pushing over the entire state (even rain and south wind in Southern CA) with moderate snow building into the Central Sierras late. A full on front with rain and south winds is expected pushing into the Central coast early Saturday (Southern CA to be spared) with heavy snow in the Central and Southern Sierras (2-3 ft).  Sunday another pulse of  rain and southerly winds is forecast focused on Central CA through effecting all of Southern CA too with heavy snow in the Central Sierra (2+ more ft). A bit of a break from the rain with lighter snow expected on Monday (12/20) though southeast winds to be in effect over th entire coast as the next system loads up offshore.  Tuesday (12/21) a fully on south wind event is to slam the Central Coast with heavy precipitation reaching down to Southern CA into Wednesday. It is unknown whether it will be rain or snow in the high Sierra.  Maybe a bit of a dryout on Thursday (12/23) as the next system loads up off the coast.  


South Pacific

At the oceans surface no swell producing fetch was occurring. Over the next 72 hours no change is forecast with no swell producing weather systems modeled. 


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 remains of the Gulf Gale are to continue circulating off Oregon Monday (12/20) generating 35 kt north wind at 40N 143W and more 24 ft seas aimed due south, midway between Hawaii and the US West Coast and likely bypassing both. And yet stronger gale is now modeled developing in the Northern Gulf of Alaska starting Tues (12/21) with 40 kt northwest winds up at 52N 152W and falling southeast a bit quicker than previous ones with a large fetch of 40 kt northwest winds at 42N 145W mid-Wed (12/22) resulting in 34 ft seas at 43N 149W Thursday AM (292 NCal, 015 Hawaii) and aimed midway between the two.  Maybe some sideband swell for both if the models are right.  At least there's some hope for sea in excess of 30 ft, the first time in weeks. 


As of Thursday (12/16) the Southern Oscillation Index (SOI) continued well in positive territory though showing limited signs of weakness. The daily SOI was up to 23.56. The 30 day average was down barely to 20.27 with the 90 day average down slightly at 19.75.  Overall, averages remained high, though down slightly from the peak in mid-to-late October (90 day average near 22.0).   

Wind anomalies as of Wednesday (12/15) at the 850 mb level (approx 5000 ft up) as defined by models indicated  that easterly anomalies were quickly dissipating the eastern North Pacific between Central America and the dateline indicative of the finally fading Inactive Phase of the MJO. The Active Phase of the MJO was building into the West Pacific. Those east anomalies (Inactive Phase) are to be gone by 12/20 while westerly anomalies (Active Phase) start pushing east to the dateline and pushing east of it on 12/25 fully straddling it on 12/30 while fading some, then easing east and fading into 1/4. We suspect the remnants of the Active Phase will push east into Central America into maybe the second week in January. Since the Active Phase supports the development of low pressure in the Northern Pacific, if anything, this is the best shot for swell in Hawaii and the US West Coast through the Christmas-New Years Holidays. Then a week after the New Year the Inactive Phase will likely be coming back and shutting it all down into early February. Sometime soon after that north winds should start building along the US West Coast as Springtime high pressure builds in much stronger and earlier than usual.

Sea Surface Temp anomaly data (12/16) continues to indicate that cold waters (-2 C degs or cooler) had a grip on the equator covering solidly from South America west to the dateline and beyond, but are not getting any colder and not expanding their coverage. And if anything, the areal coverage of the coldest waters was limited to the dateline region,with hints of warmer water building from Ecuador to a point south of Hawaii. it appears we might have already reached the peak of this La Nina event, but that remains far from certain.  The models suggest a second surge of this La Nina event is to develop and take hold by late Jan-early Feb, which will likely send water temps much colder.  Colder than normal waters covered the equator from Ecuador west to New Guinea with feed bands originating off the US West Coast and South America sweeping fully to the intersection of the dateline and the equator, only serving to reinforce what is already a solid 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.  Looks like a classic La Nina setup.  Below the surface on the equator no Kevin Wave activity was present and if anything colder than normal water was strong on the equator south of Hawaii and locked in position (sort of like a stationary cold Kelvin Wave). Previously this pocket down to 7 degs below normal in mid- Sept and 6 degrees below normal on 10/18. But it has warmed to 3 degs below normal on 12/9 and was starting to move east and not getting any colder as of 12/16.  This is most interesting and possibly suggests the peak of La Nina may have already been reached.   

Over the entire Equatorial Pacific trades were blowing all the way to the Philippines and beyond. From a historical 'normal' perspective these easterly winds were fully anomalous, blowing harder than normal from the east to the west, as would be expected looking at all the other data. But this only occurred starting in late Sept, with only normal winds indicated prior to 9/11.  Looking at the Pacific equatorial current as of 12/5, it is now running slightly anomalously west to east, completely contrary to it's previous flow and a bit unusual for a La Nina year. It actually started this pattern in early November.  This likely e.cgiains the rise in negative subsurface temperatures under the equator.    

Of note; The Pacific current that runs along the equator turned abruptly from flowing towards South America to flowing towards the Philippines in mid-March (2010), right as the SOI started it's impressive drive into positive territory and the North Pacific winter storm machine abruptly shut down. And it did not waiver until Oct 2010. But trades never wavering from the normal range.  This suggests trade wind anomalies might be a byproduct of the Pacific equatorial current change and not the other way around i.e. the trades do not drive the temperature change initially, but the current change does. And then the atmosphere responds in kind to the change, building high pressure and reinforcing the flow and water temps. Said a different way, the change in the current might actually foretell a coming change in the trades, and then with the advent of the trade wind change, it only serves to reinforce the current in a self a.cgiifying loop, until such time as the cycle runs it's course and the self feeding system collapses over a multiyear period. At that time the current then switches direction, and a whole new self-enforcing cycle stars anew. Something to consider (regarding the formation and El Nino/La Nina).    If this is true, and if the current change on the equator as of November is real, then we should start seeing signs of a faltering La Nina, with the pocket of cold subsurface water under the equator being the first piece of that puzzle.  Something to monitor.   

regardless, for now a moderate.cgius strength La Nina Pattern (where the Inactive Phase takes control) is in control and momentum from it is expected to hold well into 2011 (and likely to early 2012). In short, the next year and half is 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.  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.       

See more details in the   El Nino update.


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

Add a STORMSURF Buoy Forecast to your Google Homepage. Click Here: Add to Google
Then open your Google homepage, hit 'edit' button (top right near graph), and select your location


Local Interest

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

Free Stormsurf Stickers - Get your free stickers! - More details Here

Read all the latest news and happenings on our News Page here

Surf Height-Swell Height Correlation Table


Contact | About | Disclaimer | Privacy
Advertise/Content | Links
Visit Mark Sponsler on Facebook Visit Stormsurf on Instagram Visit Stormsurf on YouTube
Copyright © 2024 STORMSURF - All Rights Reserved
This page cannot be duplicated, reused or framed in another window without express written permission.
But links are always welcome.
Buoys | Buoy Forecast | Bulletins | Models: Wave - Weather - Surf - Altimetry - Snow | Pacific Forecast | QuikCAST | El Nino | Tutorials | Great Circles | Calculator