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Pacific Storm and Surf Forecast
Updated: Saturday, April 18, 2015 6:19 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 = 2.2 - 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 4/20 thru Sun 4/26

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   

North Pacific Slowing Down
Small New Zealand Swell Pushing Towards Hawaii

Swell Classification Guidelines

Significant: Winter - Swell 8 ft @ 14 secs or greater (11+ ft faces) for 8+ hours (greater than double overhead).
- Head high or better.
Advanced: Winter - Swell and period combination capable of generating faces 1.5 times overhead to double overhead (7-10 ft)
Summer - Chest to head high.
Intermediate/Utility Class: Winter - Swell and period combination generating faces at head high to 1.5 times overhead (4-7 ft).
- Waist to chest high.
Impulse/Windswell: Winter - Swell and period combination generating faces up to head high (1-4 ft) or anything with a period less than 11 secs.
- up to waist high swell. Also called 'Background' swell.

On Sunday, April 19, 2015 :

  • Buoy 51201 (Waimea): Seas were 5.9 ft @ 11.8 secs with swell 3.2 ft @ 11.5 secs.
  • Buoy 46025 (Catalina RDG): Seas were 3.0 ft @ 16.0 secs with swell 1.6 ft @ 14.5 secs. Wind north 6 kts. In Santa Barbara swell was 2.3 ft @ 14.8 secs from 261 degrees. At Santa Monica swell was 1.7 ft @ 15.0 secs from 232 degrees. Southward from Orange County to San Diego swell was 2.8 ft @ 16.8 secs from 267 degrees.
  • Buoy 46012 & 029 (Half Moon Bay): Seas were 10.0 ft @ 14.3 secs with swell 5.8 ft @ 13.9 secs. Wind east-southeast 5-10 kts. Water temp 53.1 degs.

Current Conditions
On Saturday (4/18) in North and Central CA surf was 2-3 ft overhead and clean but inconsistent and foggy. Down in Santa Cruz surf was shoulder high and clean and inconsistent. In Southern California up north surf was waist to chest high and clean but with a little lump running through it. Down south waves were chest to head high on the sets and clean. Hawaii's North Shore was getting the last dribbles of the dateline swell with waves waist to chest high and clean. The South Shore was flat and clean. The East Shore was getting waist high east windswell and chopped from brisk trades.

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

Meteorological Overview
Low pressure was tracking through the Northern Gulf of Alaska with it's 30 kt winds trying to get some purchase on the oceans surface, but not very successfully. Otherwise swell from a storm that tracked through the Western Gulf of Alaska on Mon-Tues (4/14) generating up to 42 ft seas was fading in California with only limited swell from the gale mentioned above pushing towards mainly the Pacific Northwest. Down south modest swell from a tiny and weak gale that was tucked up along the east side of New Zealand on Mon-Tues (4/13) producing up to 32 ft seas was pushing northeast towards Hawaii. Beyond the model suggest a weak gale pushing north in the Southeast Pacific next weekend (4/25) generating 30 ft seas. But even that meager forecast seems optimistic this far in advance. At least there's something to monitor. 

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

North Pacific

Jetstream- On Saturday (4/18) the jet was .cgiit pushing off Asia with the southern branch tracking east off Japan and the northern branch pushing southeast off the Kamchatka. The two branches merged over the dateline forming a decently configured trough but with only 100 kts winds flowing into it, offering only minimal support for gale development there down at lower levels of the atmosphere. East of the there jet remained mostly consolidated ridging up into North Canada. Over the next 72 hours the dateline trough is to push east into Northern Gulf, remain weak and eventually falling south and pinched, pushing into Southern California on Thurs (4/23). No real support for meaningful low pressure is projected. Beyond 72 hours a consolidated jet is to be pushing off Japan ridging some over the dateline then falling into what almost looks like a trough in the Western Gulf by Fri (4/24), then .cgiitting with the northern branch pushing up into Canada and the southern branch tracking into Baja. There's limited support for gale development in the trough in the Western Gulf with 130 kts winds feeding it.

Surface Analysis - On Saturday (4/18) swell from a previous Dateline Storm was fading in California (see Dateline-Gulf Storm below). A secondary low pressure system developed in the Gulf on Fri (4/17) tracking east with southwest winds in it's front building to 35-40 kts generating 22-24 ft seas Friday evening at 50N 152W but all aimed northeast at Alaska. Another tiny fetch of 35 kt west winds was in.cgiay in the Gulf from this systems Sat AM (4/18) generating 20-22 ft seas at 47N 160W then expected to dissipate Sun AM (4/19). Some sideband swell with period at 13-14 secs to reach the Pacific Northwest with even less into California. See QuikCASTs for details.    

No other swell producing fetch is forecast.


Dateline-Gulf Storm
A storm that had been on the charts for days started developing in an upper trough west of the dateline Sun AM (4/12) with 50 kts northwest winds and getting traction on the oceans surface. By evening 50-55 kt west winds were generating 36 ft seas over a tiny area at 44N 172E. By Mon AM (4/13) the storm was pushing over the dateline with 50 kt west winds making a decent footprint and seas 41 ft at 44N 180W aimed mainly east (326 degs HI, 297 degs NCal).  By evening 45 kt west winds were racing into the Western Gulf with seas holding at 41 ft at 45N 172W targeting sideband energy at Hawaii (338 degs) and more direct but distant energy at the US West Coast (298 degs NCal). 40 kt west winds were holding in the Gulf on Tues AM (4/14) with 37 ft seas at 47N 163W (299 degs NCal).  Fetch faded from 40 kts in the evening with seas fading from 32 ft at 48N 155W targeting only the US West Coast and mainly the Pacific Northwest. This system was gone by Wed AM (4/15). Some moderate size swell is expected to result for Hawaii and the US West Coast, but limited by the storms relatively small footprint and fast forward speed.

Hawaii:  Residuals to be fading Fri AM (4/17) from 4 ft @ 12-13 secs early (5 ft). Swell Direction: 324-330 degrees 

Southern CA: Swell fading on Sun (4/19) from 2.4 ft @ 14 secs (3.0-3.5 ft). Swell Direction: 300-306 degrees 

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


Tropical Update
No tropical systems of interest were being monitored.

California Nearshore Forecast
On Saturday (4/18) high pressure at 1032 mbs was ridging into the Pacific Northwest generating 25-30 kt north winds over Cape Mendocino but generally staying off the Central CA coast. More of the same is expected Sunday but with winds dropping to 25 kts in the Cape Mendo gradient and a possible south wind eddy flow developing for Central CA. The gradient to fade on Monday as a large high pressure system builds starting to fill the Northeast Pacific and weak low pressure develops inland over Nevada with upper level short waves pushing down the Pacific Northwest Coast.   The high to start pushing onshore over North California on Tuesday (4/21) with north winds building to 30 kts late and 35-40 kts by Wednesday (again isolated to North CA) with an eddy flow for Central CA. Winds to be 35 kts on Thursday for Cape mendocino with and eddy flow holding from Pt Reyes southward. The gradient is to start fading on Friday with 10 kts south winds in control for the whole state on Sat (4/25).   


South Pacific

Surface Analysis  
On Saturday (4/18) high pressure at 1036 mbs was locked just east of New Zealand pushing the storm track to the south along the Ross Ice Shelf. Over the next 72 hours the high is to slowly fade but still continue influencing the storm track. No swell producing fetch of interest is forecast.

Fiji Gale
On Saturday AM (4/11)
a small gale started developing in the South Tasman Sea with 40 kt southwest winds over a broad area generating 24 ft seas at 52S 148E targeting Fiji. 40 kt southwest winds to start pushing better up into the Tasman Sea in the evening resulting in 28 ft seas at 46S 155E. South winds to be fading from 30-35 kt then moving into the core of the Tasman Sea on Sun AM (4/12) producing 26 ft seas at 42S 159E targeting Fiji well. Fetch to fade from 30 kts pushing northeast in the evening with seas fading from 24 ft at 38S 165E. Something to monitor relative to Fiji.

Fiji: Swell arrival expected near noon on Wed (4/15) local time with period 16 secs and building pushing 7.5 ft @ 15-16 secs late (11-12 ft Hawaiian). Swell fading from 8.4 ft @ 15 secs (12-13 ft Hawaiian) Thurs AM (4/16). Swell Direction 203 degrees

Hawaii:  Tiny swell possible starting late Sun (4/19) at 1.1 ft @ 16 secs (1.5-2.0 ft). Residuals on Mon (4/20) at 1.3 ft @ 15 secs  (2 ft). Swell Direction: 210 degrees


New Zealand Gale
A tiny gale developed tucked along the east edge of New Zealand Mon AM (4/13) producing 45 kt south winds and 28 ft seas over a pinpoint sized area at 46S 177E aimed north. This system held its ground while building in the evening with 40 kt south winds growing in coverage and seas building to 26 ft at 45S 1780E. This system built Tues AM (4/14) with 45-50 kt south winds and covering more area with seas to 32 ft at 45S 179W aimed due north. The gale faded in the evening but with 35-40 kt south winds over a solid area aimed north with 24-26 ft seas fading at 43N 172W. Winds were fading from 35 kts from the south on Wed AM (4/15) with seas 24 ft at 45S 178E. The gale dissipated after that. Perhaps some modest background swell to result for Hawaii. 

Hawaii: Expect swell arrival late on Mon (4/20) with swell to 1.5 ft @ 16-17 secs  (2.0-2.5 ft). Swell peaking on Tues (4/21) at 2.2 ft @ 15 secs (3.0-3.5 ft). Swell holding at 2.3 ft @ 15 secs (3.5 ft) on Wed (4/22).  Swell starting to fade on Thurs (4/23) from 2.3 ft @ 14 secs (3.0-3.5 ft). Swell Direction: 199 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 another fetch is to develop in the Gulf of Alaska on Wed AM (4/22) generating a small area of 40 kt west winds and 22 ft seas at 51N 152W. Winds to briefly build to 45 kts in the evening with seas to 28 ft at 52S 148W aimed east at Central Canada (315 degs NCal). The gale is to push east on Thurs AM (4/23) and fade from 35 kts with seas dropping from 24 ft at 53N 143W and outside the NCal swell window. Small north angled swell possible mainly for the Pacific Northwest with limited exposure for North California.

Also on Wed PM (4/22) another gale is to push off Kamchatka with near 40 kts generating 22 ft seas at 48N 163E targeting Hawaii somewhat. 35 kt west winds to push east on Thurs AM (4/230 generating 22 ft seas at 47N 172E. Fetch is to dissipate after that. Limited 13-14 sec period swell possible for Hawaii if one is to believe the models.    

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).

(1st paragraph in each section is new/recent data. 2nd paragraph where present is analysis data and is updated only as required).
Southern Oscillation Index (SOI) On Thursday (4/16) the daily SOI was steady at 5.90. (has not updated in 3 days). The 30 day average was rising from -6.41 and the 90 day average was steady at -7.06. The near term trend based on the daily and 30 day average was indicative of a fading Active Phase of the MJO. The longer term pattern was indicative of a weak steady state Active Phase of the MJO. Weak high pressure was over Tahiti and expected to slowly fade starting Mon (4/20) as low pressure develops southwest of Tahiti and falling south. The SOI to fall some, then rebound starting Fri (4/24). The SOI tends to be a lagging indicator.   

Current equatorial surface wind analysis indicated modest westerly anomalies developing near the dateline region reaching south of Hawaii and halfway to the Galapagos Islands before turning neutral. Down at the surface the TOA array indicated modest westerly anomalies in the Eastern Kelvin Wave Generation Area holding over the dateline, south of Hawaii and nearly into the Galapagos.  A week from now (4/25) modest westerly anomalies are to build over the Maritime Continent reaching over the dateline, continuing south of Hawaii, then fading 1/2 way to the Galapagos. This suggests the Active Phase (or at least westerly anomalies) are to hold a week out (a good sign). 

A moderate Westerly Wind Burst (WWB) developed from 1/15-2/20 then regenerated 2/25 building steadily into the strong category by 3/7, before peaking 3/10 holding to 3/17. A more modest version of it continued into 3/27 then slowly faded into 3/30 but not out even to 4/11. This was already a decent event attributable to the Jan-Feb anomalies, before it raged in mid-March.See our new Kelvin Wave Generation Area monitoring model here .

The longer range Outgoing Longwave Radiation (OLR) models (dynamic and statistical) run on 4/17 suggests a modest version of the Inactive Phase of the MJO was over the dateline while the Active Phase of the MJO was weak in the Eastern Indian Ocean. Beyond the Statistic model suggests the Inactive Phase is to fade just east of the dateline 10 days out with the Active Phase pushing weakly into the West Pacific 15 days out. The Dynamic model suggests much the same with the Inactive Phase weak and fading on the dateline, with a weak Active phase developing near the dateline 10 days out and holding, but with a stronger Inactive Phase building in the Eastern indian Ocean. So the two models are opposite each other.  The ultra long range upper level model run on 4/18 depicts a neutral MJO pattern in.cgiay and no change forecast till 4/26. At that time the Inactive Phase is to form in the far West Pacific and is forecast to slow track east and fading, with remnants arriving in Central America on 5/16.  A weak Active Phase is suppose to build in the West Pacific 5/16 and is to be tracking east. The upper level model tends to be a leading indicator, with surface level anomalies lagging behind 1 week or more.    

Surface Water Temps: The more warm water in the equatorial East Pacific means more storm production in the North Pacific during winter months (roughly speaking). Cold water in that area has a dampening effect. Regardless of what the atmospheric models and surface winds suggest, actual water temperatures are a ground-truth indicator of what is occurring in the ocean.  

As of the most recent low res imagery (4/16) a weak warm water/El Nino like regime has taken control of the entire equatorial Pacific. And warmer water is getting traction along the Chilean and Peruvian coasts pushing north up to the equator, with a small warm pocket depicted between the Galapagos and the mainland. This is something not seen last year at this time. Warmer water extends west from there but only reaching 2-3 degrees south of the equator until it reaches the dateline, then expanding in areal coverage. It is this pocket of cooler water south of the equator that is of some concern, possibly limiting long term transition to a legit El Nino pattern. TAO data indicates +1.0 anomalies are in control over the entire equatorial Pacific, the warmest in years. The CDAS NINO 3.4 Index suggest water temps are warming steadily, currently at +1.0 degs, previously peaking late Nov at about +1.0 then falling to 0.0 in early January. It will be interesting to see if heating above 1.0 degs will occur in the coming month of so.  

Subsurface Waters Temps on the equator are no longer warming and are pushing hard east. As of 4/18 a +2.0 C anomaly flow was in control under the equatorial Pacific from 150 meters up. And a large pocket of +4-5 deg anomalies continued holding coverage with its core at 140W, and it's leading edge now at 107W driven by the extended WWB that occurred 1/15-2/20 and additional strong westerly anomalies in March, feeding even more warm water into that Kelvin Wave. This Kelvin Wave is expected to start erupting over the Galapagos on roughly 5/1 peaking on 6/10. According to TAO data, +3 degs anomalies are already rushing east, flowing into the Galapagos ahead of schedule and deflecting up and down the South America Coast. Satellite data from 4/8 depicts 0-+5 cm anomalies over the entire equatorial Pacific east of 170E with a core to +10 cm from 170W to 110W indicative of an open pipe with an embedded solid Kelvin Wave. The latest chart of upper Ocean Heat Content (4/8) indicates +0.5-1.0 deg anomalies are tracking east between 172E-88W with +1.0-1.5 degs from 180E-92W and +1.5 deg anomalies from 170W-108W. And now a building core of 2 deg anomalies are indicated between 156W-120W. Their coverage is building while pushing east. This also supports the thesis that another Kelvin Wave, and strong at that, is in-flight. A quick analysis of last years Large Kelvin Wave event that occurred in this same time frame, and this years event are remarkably similar in size and strength. Theoretically the peak of what was thought to be a developing El Nino occurred last December (12/21/14) with no more Kelvin Wave development expected beyond if last year was to be a single year event. But if this is a true multiyear Modoki El Nino event, then it would not be unexpected to see another Kelvin Wave develop in the Jan-Feb 2015 timeframe (as is actually occurring). See current Upper Oceanic Heat Content chart here.   

Pacific Counter Current data as of 4/2 is improving. The current is pushing moderately west to east over the entire equatorial Pacific and with a solid pulse just west of the Galapagos. A very weak easterly current was positioned 2-3 degrees south of the equator. Anomaly wise - modest west anomalies were in control on the equator over the West Pacific then north of the equator from Hawaii to the Galapagos. 

This data suggests a general west to east bias in the current suggesting warm water transport to the east. 

Projections from the monthly CFSv2 model run 4/18 for the Nino 3.4 region continue unchanged. It suggests water temps are at +1.0 deg C and are to slowly warm into July reaching +1.8 degs C, and continuing to +2.35 degs by Oct and 2.45 degs by late Nov, then dropping off. This suggests that perhaps we are moving from a multi-year steady state Modoki event to perhaps a full blown El Nino. But it is too early to believe that just yet. The model is likely just picking up on the Kelvin Wave in flight and will settle back down after it erupts over the Galapagos. Much more warm water would be too be transported east over the coming 6 months for a legit El Nino to develop, especially of the magnitude projected by the model (rivaling the all time great '97 El Nino). The mid-March consensus Plume suggests a continuation of Modoki ENSO, though some models are now suggesting something more. See the chart based version here - link. 

Analysis: Mult.cgie downwelling Kelvin Waves generated by suppressed trades and occasional Westerly Wind Bursts occurring late 2013 though 2014 in the West Pacific. Those Kelvin Waves warmed waters over the Eastern equatorial Pacific, but not sufficiently to declare an official El Nino until Feb 2015, and then very weak at that. Still some degree of teleconnection or feedback loop between the ocean and the atmosphere was in.cgiay with some greater force dictating the pattern (possibly the PDO).  The focus now becomes whether this warming and resulting teleconnection will persist if not strengthen in 2015. We are in the Spring Unpredictability Barrier (March-May). The real teller will be during the month of June. Water temps in the Nino 1.2 region are expected to be quite warm due to the arrival of a large Kelvin Wave currently in flight (see details above). If that warming is sufficient to start the classic El Nino feedback loop, then continued westerly anomalies and WWBs should continue through July-Sept and beyond, with a full scale El Nino developing. But if the cool upwelling Phase off the Kelvin Wave cycle develops in mid-June, then it will likely be another year of the Modoki El Nino cycle. The June to early July timeframe will either make or break development of a legit El Nino.    

We continue monitoring Westerly Wind Bursts and Kelvin Wave development, suggestive of continued warming East Pacific equatorial waters for the 2015 (meaning enhanced support for the jetstream and storm development in Fall/Winter 2015-2016). 

See imagery in the ENSO Powertool and more details in the  El Nino Update Updated 12/4/13 


South Pacific

Beyond 72 hours a storm is to be tracking flat east south of the Tasman Sea on Tues PM (4/21) generating 55 kt west winds and 44 ft seas at 58S 140E (218 degs CA and unshadowed, shadowed by New Zealand in Hawaii), then fading Wed AM (4/22) with winds dropping from 45 kts and seas 38 ft at 60S 150E (216 degs CA, still shadowed in HI) , fading from 40 kts in the evening and seas dissipating from 32 ft at 61S 165E (211 degs CA and starting to be shadowed, but becoming unshadowed for HI at 197 degs). Something to monitor.

Remnants of the above system are to push east fast then start riding up the east side of high pressure in the Southwest Pacific Sat (4/25) regenerating some with 40 kt southwest winds and seas building to 36 ft at 45S 130W aimed well at California. Something to monitor. 

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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