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Pacific Storm and Surf Forecast
Updated: Saturday, May 13, 2017 1:20 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
1.0 - California & 1.0 - 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 5/15 thru Sun 5/21

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   

Models Hint at Southern Hemi Storm
North Pacific Goes to Sleep


On Saturday, May 13, 2017 :

  • Buoy 146 (Lanai): Seas were 3.1 ft @ 13.3 secs with swell 2.3 ft @ 13.2 secs from 196 degrees.
  • Buoy 46025 (Catalina RDG): Seas were 4.5 ft @ 10.0 secs with swell 2.6 ft @ 10.2 secs from 271 degrees. Wind northwest 8-10 kts. Water temperature 62.1 degs. At Ventura swell was 4.3 ft @ 6.5 secs from 262 degrees. At Santa Monica swell was 2.9 ft @ 10.2 secs from 264 degrees. At Camp Pendleton swell was 2.7 ft @ 6.4 secs from 267 degrees. Southward at Pt Loma swell was 4.0 ft @ 9.4 secs from 280 degrees.
  • Buoy 46012 (Half Moon Bay)/029 (Pt Reyes): Seas were 9.2 ft @ 10.5 secs with swell 7.0 ft @ 10.4 secs from 296 degrees. Wind northwest 16-20 kts at the buoy. Water temp 54.0 degs.

    46006, 46059, Hi-Res Buoy Dashboards (bottom of the page)

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.

Surf Heights for Hawaii should be consider 'Hawaiian Scale' if period exceeds 14 secs.


Current Conditions
On Saturday (5/13) in North and Central CA local windswell and Gulf windswell was hitting producing surf at 1-2 ft overhead and somewhat lined up but pretty warbled and chopped from local northerly winds. Protected breaks were shoulder high or so and cleaner but still warbled. At Santa Cruz windswell/Gulf swell combo was waist to chest high and clean but soft. In Southern California up north local windswell was producing waves in the waist high range and clean early. In North Orange Co surf was waist to chest high on the sets and soft coming from the northwest and textured from northwest wind. In South Orange Co surf was waist high or so and textured from north wind. In San Diego northwest windswell was producing surf at chest to shoulder high and textured from northwest wind. Hawaii's North Shore was near flat and clean. The South Shore had waist high sets and was clean. The East Shore was getting local east windswell at shoulder to head high and chopped from east trades.

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

Meteorological Overview
On Saturday (5/13) local windswell and windswell from a low pressure system previously in the Gulf of Alaska was hitting California and unremarkable. No swell from the Southern Hemi was in the water. A weak gale was developing in the far Southeast Pacific today with seas forecast building to 33 ft before moving out of the California swell window. Little to result from it. But long term the models suggest a storm building south of New Zealand on Fri (5/19) with up to 50 ft seas aimed north. Something to monitor. Summer is here.

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

North Pacific

Surface Analysis
On Saturday (5/13) windswell from a gale previously in the Gulf was hitting California and mixing with local windswell generated by high pressure at 1038 mbs filling the Gulf of Alaska and producing the standard summer time pressure gradient along the coast.

Also a tiny gale developed over the Northern Dateline region on Thurs PM (5/11) producing 40 kt west winds for 12 hours generating 23 ft seas at 50N 177W. This system was gone 12 hours later. No swell of interest is to result for either Hawaii or California.

Over the next 72 hours high pressure is to remain in control along the CA coast with northwest winds at 20 kts or greater into Tues AM (5/16) generating raw local northerly windswell. The high was also generating enhanced trades (east wind) from California to and extending over Hawaii at 20 kts and forecast to hold into late Monday (5/15) then fading Tuesday (see QuikCASTs for details).

Also low pressure is to develop off the Kuril Islands Sat-Sun (5/14) with 30-35 kt northwest winds producing up to 18 ft seas at 40N 167E at 06z Sun (5/14) somewhat targeting Hawaii. It is to fade from there. This system is to be a long ways away with low odds of any swell resulting.


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


Tropical Update
No tropical systems of interest are being monitored.

California Nearshore Forecast
On Saturday (5/13) high pressure was centered in the Gulf of Alaska at 1036 mbs with north winds in control of the California coast except for Southern CA. Winds were near 30 kts just off Pt Conception early but only 10-15 kts from San Francisco northward to Cape Mendocino but building there in the afternoon. Sunday northwest winds build to 20 kts for all of North and Central CA and up to 25 kts for Pt Conception pushing into Southern CA in the afternoon. The gradient is to hold on Mon (5/15) with northwest winds 20-25 kts for all of North and Central CA pushing into Southern CA in the afternoon. North winds moderating some on Tues (5/16) at 10-15 kts for all of North and Central CA and 20 kts for Pt Conception. Wednesday northwest winds build to 20-25 kts for all of North and Central CA and building into Southern CA late AM. More of the same on Thurs (5/18) but with light winds for Southern CA. The gradient lifts north and fades on Fri (5/19) with north winds 20 kts focused only on North CA with 10 kt north winds from San Francisco southward. The gradient fades more on Saturday (5/20) with north winds 15-20 kts for Cape Mendocino and 10 kts or less south of there.


South Pacific

On Saturday AM (5/13) the jetstream was generally split over the entire southern hemi with the northern branch running east on the 30S latitude line and the southern branch on the 60S line. A ridge in the northern branch was in play over the Southeast Pacific causing the northern branch to merge with the southern branch starting at 140W and most pronounced just off Southern Chile. There was something that almost looked like a trough in the southern branch near 130W offering weak support for gale development and then better support just off Chile. Over the next 72 hours the split zonal flow is to continue with the northern branch still falling south over the Eastern South Pacific and something that sort of looks like a trough persisting from 120W into Chile through Tues (5/16) offering some support for gale development mainly focused on Chile. Beyond 72 hours
more of the same is forecast (split zonal flow) over the greater South Pacific but with a defined steep trough developing in the far Southeast Pacific just off Chile being fed by 140 kt winds offering decent support for gale development targeting Peru and Chile on Tues (5/16) then moving onshore there. Longterm the models continue to suggest a defined trough building under New Zealand on Thurs (5/18) being fed by 140 kt winds and holding form into Sat (5/20) possibly supporting gale development in lower levels of the atmosphere.

Surface Analysis  
On Saturday AM (5/13) no southern hemi swell was in the water.

Over the next 72 hours a gale started to develop in the deep Southeast Pacific on Fri PM (5/12) with 40 kt west winds and seas building. On Sat AM (5/13) winds built to 45 kts from the south with seas building to 32 ft at 57S 130W. In the evening winds are to hold at 45 kts but coming from the southwest aimed more at Chile with seas 33 ft at 63S 120W and 30 ft seas reaching north to 53S 120W and barely in the California swell window. By Sun AM (5/14) fetch is to be fading from 40 kts moving east and out of the CA swell window targeting only Chile with seas 33 ft 63W 115W. Possible small south angled swell for Southern CA. Something to 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 hours the models suggest some form of low pressure system developing in the Gulf of Alaska on Sat (5/20) producing 30-35 kts west winds and seas to 19 ft at 42N 155W.

After that the North Pacific is to go to sleep.

South Pacific

Beyond 72 hours there's suggestion of a broad gale developing Wed PM (5/17) south of New Zealand with winds 40 kts from the south-southwest and seas building from 32 ft at 51S 159E. Fetch is to build in coverage Thurs AM (5/18) at 35-40 kts from the southwest over a large area with 30 ft seas building at 49S 165E aimed well to the north but mostly shadowed by New Zealand. Significant development is forecast in the evening with a broad fetch of 45-50 kt south winds taking shape well south of New Zealand with seas building from 28 ft down at 60S 168E with 33 ft seas at 51S 167E. By Friday AM (5/19) a large area of 50-60 kt south winds are forecast well south of New Zealand with 43 ft seas building at 59S 173E targeting New Zealand, Hawaii and California (195 degs HI, 210 degs NCal and barely unshadowed by Tahiti, 210 degs SCal and shadowed). The fetch is to lift north in the evening fading to 50 kts with 50 ft seas at 53S 178E (195 degs HI, 213 degs Ncal and unshadowed, 215 degs SCal and shadowed). Fetch fading Sat Am (5/20) from 40 kts from the south with 40 ft seas fading at 49S 173W (192 degs HI, 211 degs NCal and barely unshadowed, 210 degs SCal and shadowed). Something to monitor.

More details to follow...


Weak Oceanic Kelvin Wave Trying to Push East

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 equator it is in control of, and in it's Active Phase by slackening if not an outright reversing trade winds while enhancing 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 planet, though most noticeable in the Pacific. 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. Prolonged and consecutive Active MJO Phases in the Pacific help support the formation of El Nino. During the Inactive Phase the jet stream tends to split resulting in high pressure and less potential for swell producing storm development. Wind anomalies in the Kelvin Wave Generation Area (KWGA) are key for understanding what Phase the MJO is in over the Pacific. The KWGA is located on the equator from 135E-170W and 5 degs north and south (or on the equator from New Guinea east to the dateline). West wind anomalies in the KWGA suggest the Active Phase of the MJO in the Pacific, and east anomalies suggests the Inactive Phase. In turn the Active Phase strengthens and the Inactive Phase weakens the jetstream, which in turn enhances or dampens storm production respectively in the Pacific.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).

Overview: La Nina started developing in early 2016, but westward displaced and generally weak. And by March 2017, it was gone with suspicious warming developing along South America and over the Galapagos to a point south of Hawaii. By May the atmosphere returned to a neutral configuration.

KWGA/Equatorial Surface Wind Analysis & Short-term Forecast:
Analysis (TAO Buoys): As of Friday (5/12) east winds were over the entire equatorial Pacific and marginally weaker in the south Kelvin Wave Generation Area. Anomalies were neutral everywhere. La Nina appears to be gone in the atmosphere.
1 Week Forecast (GFS Model): East anomalies were building over the core of the KWGA. The forecast suggests strong east anomalies building over the entire KWGA and holding through 5/18, then backing off some and tracking east but still in control of the Central KWGA. This suggests the Inactive Phase of the MJO was moving over the KWGA.

Kelvin Wave Generation Area wind monitoring model: West and East

Longer Range MJO/WWB Projections:  
OLR Models: As of 5/12 a building Inactive/Dry MJO pattern was moving over the KWGA. The statistic model projects the Inactive Phase tracking east to the dateline over the next week then fading while the Active Phase builds in the Indian Ocean moving to the Maritime Continent 2 weeks out. The dynamic model depicts the same thing. All this suggest that the previous pattern of the Inactive Phase of the MJO constructively integrating with the remains of La Nina appears to be gone and a more balanced/normal ENSO Pattern is taking hold.
Phase Diagrams 2 week forecast (ECMF and GEFS): (5/13) The ECMF model indicates the Active Phase of the MJO was modest over Northeast Africa and is forecast to track east quickly to the Indian Ocean 10 days out and then to the Maritime Continent 2 weeks out. The GEFS depicts the same thing. These models runs about a week ahead of what occurs down at the surface.
40 day Upper Level Model: (5/13) This model depicts a modest Inactive Pattern over the dateline. It is to track east to Central America through 5/26. A very weak Active pattern to follow in the West Pacific 5/24 tracking east to the East Pacific through 6/17. A very weak Inactive Phase is to follow in the West Pacific 6/22. This model runs about 2 weeks ahead of what happens at the surface.
CFS Model - 3 month (850 mb wind): (5/13) This model depicts the Inactive Phase of the MJO was over the Central KWGA with modest east anomalies in play in the KWGA. Beyond the Inactive Phase is to peak on 5/20 then fade but still holding through 6/7 with weak westerly anomalies in the Central KWGA by 5/21 but fading by 5/27 with neutral anomalies in control. After that the Active Phase is to move into the KWGA on 6/15 with light west anomalies building, getting solid 7/1 and holding decently through 8/9 (the end of the run). This is likely overstated a the model has been teasing of west anomalies for months and yet they never develop. The low pass filter indicates La Nina is to hold on in the KWGA till 6/2 (previously 5/6-5/8). There's no signs of El Nino developing. It will take 5 years or more for the Pacific to recharge from the 2014-16 El Nino.

CFSv2 3 month forecast for 850 mb winds, MJO, Rossby etc

Subsurface Waters Temps
TAO Array: (5/13) Actual temperatures remain stratified with warm water in the West Pacific at 30 degs C steady at 159E. The 28 deg isotherm line continues is steady at 149W. The 26 deg isotherm continued easing to the east reaching to the Galapagos with the 24 degs isotherm over a modest pool down 25 meters (75 meters at 140W) and holding. Warm anomalies at +2 degs are in the East Pacific and +2 degs anomalies in the West Pacific down at 125m. More interesting is a thin stream of +1 degs anomalies now stretch from the west to the east indicative of some form of weak Kelvin Wave. The hi-res GODAS animation posted 5/8 depicts that warm water is fading in the East Pac at +0-1 degs in a few small pockets easing east over a shallow pool to about 145W. Cool water at -1-2 degs is at depth between 110W-150W but is noticeably loosing coverage. A warm pocket at +4 degs is at 180W and trying to move east. La Nina has lost control of the ocean at depth with something that almost resembles a warm pattern taking shape. The concern is there is not much warm water in the far West Pacific to feed any sort of a progressive Kelvin Wave pattern.
Sea Level Anomalies: (5/8) +0-5 cm anomalies are along the coast of Peru and Ecuador but are fading. In the west +5 cm anomalies are over the entire KWGA and pushing east now reaching to 130W, suggestive of a weak Kelvin Wave tracking east. La Nina is gone in the East Pacific with a neutral to weak warm trend trying to hold on.

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. All data is from blended infrared and microwave sensors.
Satellite Imagery
Hi-res Nino1.2 & 3.4: (5/12) The latest images (1.2 3.4) indicate a generalized warm pattern is building along the coasts of Northern Chile and Peru north to Ecuador then extending west over the Galapagos and out to sea out to 160W. Warming to +2 degs is in multiple pockets in this region. Upwelling along the immediate coasts of Peru and North Chile is all but gone. Looking at the large picture, warming in the southern hemi extends east thousands of miles off the coast of South America as far south as 20S or more. But it is not well defined. La Nina is gone and it looks like an El Nino like pattern is returning, though that seems hard to believe given the limited volume of subsurface warm water in the West equatorial Pacific.
Hi-res 7 day Trend (5/12): A warming trend is developing along immediate Chile and Peru. Marked warming extends off Ecuador to the Galapagos and then out to 100W in a thin stream. A weak warming trend is present in the Northern Hemi modesty from Oregon out to Hawaii reaching west to the Philippines. Overall nothing remarkable is indicated.
Hi-res Overview:
(5/10) There is no sign of La Nina anywhere on the equator. A solid warm regime holds from Ecuador west to 140W and less energetic out to the dateline. It looks like El Nino is trying to develop and making headway into the Nino3.4 region. Overall waters of all oceans of the planet are warmer than normal. Suspect climatology needs to be updated to reflect this new reality, or the recent Super El Nino has significantly redistributed heat across the oceans.
Nino1.2 Daily CDAS Index Temps: (5/13) Today's temps are rising steadily at +0.579, down from the peak of +3.0 degs on 3/18.  
Nino 3.4 Daily CDAS Index Temps: Today (5/11) temps holding, hovering at +0.482 degs.

Click for Full Sized Image

CFSV2 Forecast for Nino3.4 SST Anomalies

SST Anomaly Projections
CFSv2 Uncorrected Data (5/13) The forecast has temps slowly falling from +0.5 degs today down to +0.35 degs in July holding into Aug, then falling to +0.25 degs in Oct dropping to +0.1 degs in Jan 2018. This suggests a weakly cooler but still normal pattern developing for the Winter of 2017-2018. CFS data suggests a Modoki style warming pattern over the dateline this Fall and Winter. La Nina is over and a return to normal temps appears to have occurred in the ocean. There is no source for greater warming with the warm pool in the far West Pacific pretty weak. Much recharging and heat buildup is required for a real El Nino to develop. We're at least 5 years out from that.
IRI Consensus Plume: The mid-April Plume updated (4/19) depicts temps are warming and are now at +0.4 degs. A slow increase in temps is forecast thereafter to +0.8 degs in July and up to +0.9 degs through the Fall into Winter. This is +0.3 degs warmer than the Feb forecast and +0.6 degs warmer than the January forecast and +0.1 degs since the March forecast suggesting La Nina is over and a warmer regime is setting up. See chart here - link. 

Atmospheric Decoupling (Indicating the presence of El Nino in the atmosphere driven by the ocean):
Southern Oscillation Index (5/13): The daily index was rising at 6.68. It was negative for the previous 14 days. The 30 day average was rising at -11.28. The 90 day average was falling at -4.73 or just south of neutral. This suggests a return to at least a neutral ENSO conditions has taken hold.
ESPI (like SOI but based on satellite confirmed precipitation. Positive is good, negative bad): (5/13) Today's value was -0.21 or effectively neutral. A peak low was reached on 11/2 at -1.94, the deepest of the recent La Nina event. This measures atmospheric response, not oceanic.

Pacific Decadal Oscillation: The PDO continues positive, though much weaker lately (as expected with La Nina setting in).
Per NOAAs index recent values (Jan-Dec): Jan 2017 = +0.12, Feb = +0.04, March = +0.08. This continues to look like the warm phase of the PDO. No consistently negative readings have occurred since Feb 2014
The Washington EDU index (Jan-Dec): Jan 2017 = +0.77, Feb = +0.70, Mar = +0.74. No negative readings have occurred since Dec 2013
The PDO turned from a 16 year negative run (Jan 98-Feb 2014) in early 2014 and has been positive ever since (other than a few months of negative readings in Fall 2016, the result of a turn towards La Nina). Looking at the long term record, it is premature to conclude that we have in-fact turned from the negative phase (La Nina 'like') to the positive phase (El Nino 'like'), but the data strongly suggests that could be a possibility. By the time it is confirmed (4-5 years out), we will be well into it.

See imagery in the ENSO Powertool


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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