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Pacific Storm and Surf Forecast
Updated: Sunday, April 18, 2021 1:21 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
4.0 - California & 1.5 - Hawaii
Using the 'Summer' Scale
(See Swell Category Table link at bottom of page)

Probability for presence of largest swells in near-shore waters of NCal, SCal or Hawaii.    

Issued for Week of Monday 4/19 thru Sun 4/25

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   

Two South Swells for CA
Perhaps Another Gale to Develop Under New Zealand

On Sunday, April 18, 2021 :

  • Buoy 233 (Pearl Harbor Entrance)/Buoy 239 (Lanai): Seas were 2.2 ft @ 18.2 secs with swell 1.2 ft @ 18.2 secs from 206 degrees. Water temp 76.1 degs (Pearl Harbor 233), 76.5 (Lani 239)..
  • Buoy 106 (Waimea): Seas were 4.7 ft @ 9.9 secs with swell 3.7 ft @ 9.3 secs from 352 degrees. Water temp 76.1 degs.
  • Buoy 46025 (Catalina RDG): Seas were 3.3 ft @ 14.7 secs with swell 1.5 ft @ 14.2 secs from 252 degrees. Wind at the buoy was north at 4-6 kts. Water temperature 59.9 degs, 59.5 (Topanga 103), 59.5 degs (Long Beach 215), 63.7 (Del Mar 153). At Harvest Buoy (071) primary swell was 4.1 ft @ 14.9 secs from 280 degrees. At Santa Monica (028) swell was 1.9 ft @ 15.9 secs from 221 degrees. At Oceanside (045) swell was 1.9 ft @ 16.0 secs from 213 degrees. Southward at Point Loma (191) swell was 2.3 ft @ 15.7 secs from 223 degrees.
  • Buoy 46012 (Half Moon Bay)/029 (Pt Reyes): Seas were 7.0 ft @ 6.7 secs with swell 2.6 ft @ 13.2 secs from 262 degrees. Wind at the buoy (012) was northwest at 14-18 kts. Water temp 49.1 (029), 53.1 degs (SF Bar) and 53.8 degs (Santa Cruz).

See 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 Sunday (4/18) North and Central CA was getting some form of weak northwest swell with waves estimated to be in the waist high range and clean but totally fogged in. Protected breaks were up to waist high and clean but soft and weak and again fogged in. At Santa Cruz surf was waist to chest high with some bigger peaks and lined up and clean but inconsistent and generally soft. In Southern California/Ventura waves were thigh high on the sets and lined up and soft and slightly textured with no local wind. Central Orange County had set waves at chest to shoulder high and lined up coming from the south but inconsistent with a light texture on the surface from northwest wind. South Orange County's best summertime breaks had sets at shoulder to head high and lined up and clean with decent form and soft. North San Diego had sets waves at waist to maybe chest high and weakly lined up and clean but soft and inconsistent with fog at many locations. Hawaii's North Shore was getting some swell with waves chest high on occasion and clean but soft and some intermixed small lump. The South Shore was still getting background swell with waves chest high occasionally and clean and lined up and peeling when the sets came. The East Shore was getting waist high easterly windswell and pretty textured from modest east trades.

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

Meteorological Overview
On Sunday (4/18) California and Hawaii were getting swell from a gale previously under New Zealand tracking east to southeast Sun-Tues (4/6) resulting in 35 ft seas. A small storm formed in the deep Southeast Pacific on Tues (4/13) lifting northeast producing up to 41 ft seas aimed northeast before moving east of the CA swell window. A second storm formed right behind it in the deep South Central Pacific Wed-Fri (4/16) producing up to 40 ft seas aimed northeast. Two swells resulted and both are tracking northeast South and Central America pushing up into Mexico and the US West Coast. And after that a small gael is forecast developing under New Zealand on Tues (4/20) tracking east into Thurs (4/22) over the Central South Pacific with seas initially 38 ft fading to 28 ft. Up north a gale was developing in the Central Gulf on Sun (4/18) forecast to produce 20 ft sea aimed east for 12 hours. And in the far West Pacific a gale is forecast off Japan on Fri (4/23) with 23 ft seas aimed east and a tropical system behind it. Otherwise local northwest windswell is projected Tues-Thurs (4/22) at exposed breaks in North and Central CA.

See all the details below...


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

North Pacific

On Thursday (4/18) the jet was pushing east off Japan forming a small trough over the coast offering some support for gale development there then splitting with the influential northern branch tracking hard north over Kamchatka then falling southeast over the dateline forming a broad trough over the Northwestern Gulf again offering some support for gale development. From there the jet tracked north over the Eastern Gulf up into Alaska. Over the next 72 hours the trough off Japan is to ease east into Wed (4/21) slowly getting better organized with winds building to 130 kts offering decent support for gale development then. And the Gulf trough is to get better organized into Tues-Wed (4/21) being fed by 130 kt winds focused north of Hawaii also offering support for gale development. Beyond 72 hours the Japan trough is to generally hold position and build slowly into Fri (4/23) easing to a point half way to the dateline and being fed by 170 kts winds offering good support for gale development. The Gulf trough is to lift northeast some into Fri (4/23) with winds 150 feeding it also offering more support for gale development. By Sun (4/25) the Gulf trough is to be poised to move onshore over north Oregon while the Japan trough also lifts northeast now repositioned over the extreme Northwestern Gulf being fed by 140 kts winds offering continued support for gale development. But given the change of seasons, whatever does develop at the surface will be weak.

Surface Analysis
On Sunday (4/18) no swell of interest (other than windswell) was hitting Hawaii or California originating in the Northern Hemisphere.

Over the next 72 hours starting Fri PM (4/16) a small low pressure system developed in an upper trough just 800 nmiles north of Hawaii producing 25 kt north winds and seas building from 12 ft at 34N 162W aimed south. Fetch built in coverage at 25 kts over a broader area on Sat AM (4/17) from the northwest but the low was lifting north fast with no seas of interest indicated. This system continued circulating while lifting north on Sun AM (4/18) producing 30-35 kt west winds well off Cape Mendocino CA producing 17 ft seas at 42N 147W aimed east and northeast. By the evening the gale was tracking north with 30-35 kt west and southwest winds producing 20 ft seas at 45N 143W aimed east and northeast. Maybe some small windswell to result for North and Central CA but it will be buried in larger local short period local windswell expected arriving at the same time.


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


Tropical Update
Typhoon Surigae was 180 nmiles east of the Central Philippines on Sun AM (4/18) producing 125 kt winds (143 mph) tracking slowly north-northwest after peaking Sat PM (3/17) with winds at 150 kts (172 mph). This is a testament to the warm ocean waters in the far West Pacific early this season and typical of La Nina. Surigae is to continue on as north-northwest track on Tues (4/20) 220 nmiles east of the Northern Philippines with winds to 100 kts. After that a turn to the northeast and east is forecast with this system 540 nmiles east of Taiwan on Fri (4/23) and winds down to 80 kts. Something to monitor through no immediate swell production is suggested for our forecast area. This system is all attributable to the Active Phase of the MJO over that area driving a Westerly Wind Burst (WWB).

California Nearshore Forecast

  • Mon (4/19) northwest winds are forecast at 20+ kts early for Cape Mendocino and 15 down down over all of Central CA building to 20-25 kts solid over all of North and Central CA later. Windswell production increasing later.
  • Tues (4/20) northwest winds are forecast at 25 kts for all of North and Central CA early and up to 30 kts for Pt Arena and the coverage of the 30 kt winds building over all of North CA later in the day. Windswell production increasing. Maybe some very widely scattered showers along the North and Central coast early. Maybe some light snow for Tahoe in the evening.
  • Wed (4/21) northwest winds are forecast at 25-30 kts for all of North CA early and 15 kts down into Central CA holding all day. More windswell production expected. Maybe some scattered showers along the Central CA coast and down into Southern CA during the day. Maybe some light snow for the Central Sierra in the evening.
  • Thurs (4/22) northwest winds are to be fading from 20-25 kts over and off North CA early and 10 kts for Central CA fading to barely 20 kts limited to Cape mendocino later and 10 kts for Pt Arena southward. Showers possible for Southern CA during the day.
  • Fri (4/23) north winds are forecast at 15-20 kts early for North CA and 10 kts for Central CA fading to 10-15 kts up north later.
  • Sat (4/24) northwest winds are forecast at 10 kts all day but turning south at 10-15 kts for Cape Mendocino later.
  • Sun (4/25) southwest winds are forecast at 10-15 kts for North CA early and up to 20 kts for Cape Mendocino and northwest 10 kts for Central CA early . Light rain possible from Pt Reyes northward.

Total snow accumulation for the next 10 days respectively for Squaw Valley, Sugar Bowl, Kirkwood and Mammoth at 0.5 inches, 0.5 inches, 1.0 inches, and 2 inches.

Freezing level 10,500 ft through 4/19 falling to 8,500 ft 4/20-4/21, then rising steadily reaching 12,000 ft on 4/23. Snow level falling again to 7,000 ft on 4/26, quickly rising to 12,000 ft on 4/27.

Snow Models: (Scroll down for resort specific forecasts). Updated!


South Pacific

Surface Analysis
On Sunday (4/18) swell continued in California originating from a gale previously under and east of New Zealand (see small New Zealand Gale below). Also 2 gales developed in the deep Southeast Pacific with swell now radiating northeast from both (see Southeast Pacific Gale & Another Southeast Pacific Gale below).

Over the next 72 hours another gale is forecast developing southeast of New Zealand on Tues PM (4/20) producing a small area of 50 kt west winds and seas 36 ft at 61S 179.5W aimed east. ON Wed AM (4/21) fetch is to lift gently east-northeast at 45 kts from the west with seas 38 ft over a small area at 59.75S 169.25W aimed east. In the evening fetch is to be pushing east at 40 kts with seas 32 ft at 60S 157W aimed east. Fetch is to be fading Thurs AM (5/22) from 35 kts from the southwest with seas 29 ft at 60S 145W aimed east. Something to monitor.


Small New Zealand Gale
A gale developed south of New Zealand on Sun AM (4/4) producing 40-45 kt west winds generating seas of 32 ft at 5S 176W. In the evening a new fetch fetch developed from the old one with 45-50 kt west winds over a tiny area with seas 35 ft at 52S 170E aimed east. On Mon AM (4/5) a solid but small fetch of 45 kt southwest winds were southeast of New Zealand with seas 32 ft at 53S 172.5W aimed east. In the evening 50 kt west winds were pushing east with seas 37 ft at 59.5S 163.5W aimed east. Fetch was collapsing and fading from 40 kts on Tues AM (4/6) over the deep South Central Pacific with seas fading from 33 ft at 62.5S 152.5W aimed east with 26-30 ft seas lingering back to the northwest to 54.5S 180W. This system was gone after that. Possible small swell for the US West Coast starting 4/14 but most energy aimed at South America.

Southern CA: Swell continues on Sun (4/18) at 2.0 ft @ 15 secs (3.0 ft). Swell fading on Mon (4/19) from 2.1 ft @ 15 secs (3.0 ft). Swell fading Tues (4/20) from 1.8 ft @ 14 secs (2.5 ft). Less swell on Wed (4/21) fading from 1.8 ft @ 14-15 secs early (2.0-2.5 ft). Dribbles on Thurs (4/22) fading from 1.6 ft @ 13-14 secs (2.0 ft). Swell Direction: 206 degrees moving to 195 degrees

North CA: Swell continues on Sun (4/18) at 2.0 ft @ 15-16 secs (3.0 ft). Swell fading on Mon (4/19) from 1.8 ft @ 14-15 secs (2.5 ft). Swell fading Tues (4/20) from 1.8 ft @ 14-15 secs (2.5 ft). Less on Wed (4/21) fading from 1.6 ft @ 14 secs early (2.0-2.5 ft). Swell Direction: 204 degrees moving to 190 degrees


Southeast Pacific Gale
A gale developed in the deep Southeast Pacific starting Tues AM (4/13) producing 50 kt southwest winds and seas building from 36 ft at 62.5S 133.5W aimed northeast. In the evening southwest winds were 45 kts lifting northeast with seas 40 ft over a small area at 59.5S 125W aimed northeast. On Wed AM (4/14) the gale was starting to race northeast with 40 kt southwest winds and mostly east of even the Southern CA swell window with seas fading from 35 ft at 55S 116W moving out of the SCal swell window. A decent pulse of south angled swell is expected to result for South and Central America with energy pushing up into the US Mainland at exposed south facing breaks.

Southern CA: Expect swell arrival on Wed (4/21) building to 1.4 ft @ 18 secs late (2.0-2.5 ft). Swell building on Thurs (4/22) to 1.6 ft @ 16-17 secs later (2.5 ft). Swell fading on Fri (4/23) from 1.6 ft @ 15-16 secs early (2.0-2.5 ft) and being overrun by new swell from the South Central Pacific. Swell Direction: 188-192 degrees

North CA: Expect swell arrival on Wed (4/21) building to 1.0 ft @ 18 secs late (1.5 ft). Swell building on Thurs (4/22) to 1.5 ft @ 17 secs later (2.5 ft). Swell fading on Fri (4/23) from 1.6 ft @ 16 secs early (2.5 ft) and being overrun by new swell from the South Central Pacific. 186-190 degrees


Another Southeast Pacific Gale - Swell #1S for SCal
A new gale started developing in the deep South Central Pacific on Wed AM (4/14) producing a decent sized fetch of 40 kt southwest winds and seas building to 25 ft at 65S 152W aimed east. In the evening a solid fetch of 40 kt southwest winds were pushing northeast with seas building in coverage at 27 ft at 63.5S 140W aimed east-northeast. On Thurs AM (4/15) south to southwest winds were building in coverage at 40-45 kts over the Southeast Pacific with seas 31 ft lifting northeast at 61S 132W. In the evening fetch built to 45-50 kts coming well from the south with seas 37 ft at 63S 127W aimed north with its leading edge at 56S 123W aimed north-northeast. On Fri AM (4/16) 40 kt south winds were over a solid area aimed north with 38 ft seas at 57.25S 120W and still in the CA swell window aimed north. In the evening this system was easing east of the swell window with 35-40 kt south winds and seas 34 ft at 53S 114W with 33 ft seas at 53S 118W in the SCal swell window aimed north. This system was fading and east of the CA swell window after that. Swell is radiating north towards South and Central America and up into Mexico and the US West Coast.

Southern CA: Expect swell arrival on Thurs (4/22) building to 1.2 ft @ 21 secs later (2.0 ft). Swell building on Fri (4/23) reaching 2.5 ft @ 19 secs late (4.5 ft with sets to 5.5 ft). Swell peaking on Sat (4/24) mid-day at 3.3 ft @ 17 secs (5.5 ft with sets to 7 ft). Swell fading some on Sun (4/25) at 3.1 ft @ 16 secs early (5.0 ft with sets to 6.2 ft). Residuals on Mon (4/26) fading from 2.6 ft @ 14 secs (3.5 ft) early. Dribbles on Tues (4/27) fading from 2.1 ft @ 13-14 secs early (2.5-3.0 ft). Swell Direction: 185 degrees

North CA: Expect swell arrival on Fri (4/23) building to 2.1 ft @ 20 secs later (4.0 ft). Swell building on Sat (4/24) reaching 2.9 ft @ 18-19 secs later (5.5 ft with sets to 6.5 ft). Swell peaking on Sun (4/25) mid-day at 3.1 ft @ 16 secs (5.0 ft with sets to 6.0 ft). Swell fading some on Mon (4/26) at 2.8 ft @ 15 secs early (4.0 ft with sets to 5.0 ft). Residuals on Tues (4/27) fading from 2.3 ft @ 14 secs (3.0 ft) early. Swell Direction: 184 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 a broad area of low pressure is to build over the Northern Gulf of Alaska Tues-Wed (4/21) producing 25-30 kt mostly west winds with seas to 15 ft aimed south or east offering no real swell production potential.

A gale is theoretically forecast developing off Japan on Fri (4/23) producing 35-40 kt northwest winds and seas building to 26 ft mid-day at 32N 160E aimed southeast. The gael is to lose coherency while tracking northeast fairly quickly after that with no meaningful sea production forecast.


South Pacific

Beyond 72 hours no swell producing fetch of interest is forecast.



MJO/ENSO Forecast


La Nina Collapsing
Summary - Strong Active MJO over the KWGA. And a previous Kevin Wave is pushing east across the Equatorial Pacific squeezing the cold remains of La Nina from depth to the surface in the far E Pac and poised to erupt south of Mainland Mexico. West anomalies to control the KWGA for the next 3 months.

MJO/ENSO Discussion
The Madden Julian Oscillation (MJO) 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.
And the El Nino/La Nino cycle (collectively know as ENSO - El Nino Southern Oscillation) is a less frequent (about once every 7 years) but more impactful cycle that affects world wide weather. Specifically, strong El Nino events promote storm production in the Pacific while La Nina events suppress storm production. These therefore have a significant impact on the production of swell and surf. The paragraphs below analyze the state of the MJO and ENSO in the Pacific and provide forecasts for upcoming activity (or inactivity depending on the state and interaction of these two oscillations).

Overview: A double dip La Nina occurred through the Winter of 2017-2018. Warming started building along the South and Central American coast in early March 2018 associated with two upwelling Kelvin Waves, and continued trying to build over equatorial waters over the Summer and Fall, but not enough to declare El Nino and not coupled with the atmosphere. In 2019, those warm waters were fading, and by August a tongue of cool water was tracking west on the equator from Ecuador over the Galapagos reaching to a point nearly south of Hawaii. A bit of a recovery tried to occur during Fall of 2019, with weak warm water building in the Nino 1.2 region, but cool water held in a pool off Peru. By April 2020 a cool pool was starting to build, forming a well defined cool tongue that looked like the start of La Nina, with it fully developing into La Nina in July 2020. We continue in the place in March 2021, but with a Kelvin Wave sweeping east late in March possibly signaling the demise of La Nina.

Winter/Spring 2020/2021 = 3.0/3.5 (California & Hawaii)
Rating based on a 1-10 scale: 1 being the lowest (small and infrequent surf conditions), 5 being normal/average, and 10 being extraordinary (frequent events of large, long period swells)

Rationale: It is assumed the PDO has moved to the warm phase in 2014 and that a weak borderline El Nino from 2018 faded out in the Fall of 2019. A La Nina like ocean temperature pattern developed in the equatorial East Pacific in the summer of 2019, then faded and returned to a neutral if not weak warm status during the Winter of 2019-2020 only to return stronger in the Summer of 2020. We have been suspecting a turn towards a La Nina like atmospheric pattern to develop in the late Winter/early Spring of 2020. Our best hope is that moderation from the warm phase of the PDO might tamp down development of a full blown La Nina as we move into 2020. But at this time that does not appear likely. Given all that, for the 2020 there is decent probability for development of La Nina meaning a reduced number of storm days and storm intensity during the summer season, resulting in a below normal level of swell, with swell being below normal duration and period. And by the Fall and early Winter of 2020/21, the number of storm days, intensity and duration of those storms should fade even more, resulting in depressed swell production. This pattern is expected to hold through the Spring of 2021.

KWGA/Equatorial Surface Wind Analysis & Short-term Forecast (KWGA - Kelvin Wave Generation Area - The area 5 degrees north and south of the equator from 170W to 135E)
Analysis (TAO Buoys): As of (4/17) 5 day average winds were strong from the east over the Eastern equatorial Pacific continuing moderate east over the Central Pacific and modest east over the KWGA. Anomalies were neutral over the East equatorial Pacific and neutral over the Central Pacific and light westerly over the KWGA. (Note: These are 5 day average winds, so they lag what is happening today by about 2 days).
1 Week Forecast (GFS Model): No update. Data for this section is likely gone forever. - On (4/14) east anomalies were moderate over the dateline. West anomalies were light over the West KWGA with the dividing line at 170E. The forecast calls for east anomalies holding at moderate status and not moving until 4/11, then moving progressively east positioned well east of the dateline at the end of the model run on 4/13. Strong west anomalies are to start building on 4/7 at 150E and building stronger still through the end of the model run moving only slightly east to 160E.

Kelvin Wave Generation Area wind monitoring model: West and East

Longer Range MJO/WWB Projections:  
OLR Models: (4/17) A moderate Active MJO pattern was filling the KWGA. The statistic model projects the Active signal fading on day 5 to modest strength on the dateline then then weak on the dateline on day 10 then gone on day 15 with a weak Inactive signal over the West KWGA. The dynamic model has the Active Phase building over the KWGA and moderate centered in the middle of it and holding unchanged through day 15 of the model run.
Phase Diagrams 2 week forecast (ECMF and GEFS): (4/18) The statistical model depicts the Active Phase was modest over the Central Pacific today and is to track east over the Indian Ocean by day 15 of the model run and exceedingly weak. The dynamic model suggests the Active Phase is to hold position for the next 5 days then starting to migrate steadily east to the Western Atlantic at modest strength on day 15 of the model run.
40 day Upper Level Model (assumed to be a statistical mode and 1 week ahead of what is occurring at the surface): (4/17) The Active Phase (wet air) was weak over the Central Pacific today and is to push east over Central America on 5/2. A solid Inactive Phase (dry air) is to move over the KWGA on 4/24 tracking east and moving over Central America on 5/17. A fairly solid Active Phase (wet air) is to push over the KWGA on 5/12 pushing to the East Pacific at the end of the model run on 5/27. A new weak Inactive MJO (dry air) is to be building in the West Pacific at that time.
4 Week CFS Model (850 mb wind): (4/17) This model depicts a coherent Active Phase of the MJO effectively filling the KWGA producing moderate west anomalies at 130E with lesser west anomalies filling the KWGA. The forecast indicates the Active Phase is to continue building in from the west with west anomalies holding at strong status through 4/22 between 135E to 150E then starting to fade as the Active Phase moves east of the KWGA on 5/4. By 5/5 west anomalies are to fade from the KWGA with neutral anomalies taking hold. A neutral winds and MJO pattern is forecast through the end of the model run on 5/15. Theoretically we are 1/3rd of the way through the first real Active Phase of the MJO in over a year.
3 Month CFS Model (850 mb wind): (4/18 - using the 4th/latest ensemble member): A dramatic upgrade has occurred in the KWGA. This model depicts a moderate Active MJO signal in control of the KWGA with modest west anomalies blowing there. The forecast indicates it is to track east through the KWGA on 5/3 producing moderate to occasionally strong west anomalies filling the KWGA. This is the first real Active Phase in a year or more. A weak Inactive MJO is to follow 4/24-6/13 but with mostly modest west anomalies filling the KWGA. A new solid Active Phase is to start building in the west on 5/28 pushing east through the end of the model run on 7/16 with moderate to strong west anomalies controlling the KWGA. Literally no significant east anomalies are forecast in the KWGA from here forward. The low pass filter indicates a high pressure bias is in control over the dateline filling the eastern KWGA but a low pressure bias was building over the West KWGA. The high pressure bias has 3 contour lines reaching east to a point south of California. The forth contour line faded on 4/11. The 3rd contour line is to fade on 5/2. The second contour line is to fade 5/24. The remaining 1 is to be shifting steadily east starting 4/25 and losing coverage and no longer in the KWGA after 5/28. A single contour low pressure bias is over the Maritime Continent with it's leading edge pushing into the West KWGA today. It is to theoretically start shrinking in coverage from the west on 4/29 while the east edge tracks east to 180W and filling the KWGA by 7/1 while building to 2 contour lines. The strong Active Phase occurring now is to be the tipping point, and has been on this model for nearly 3 months. Still, it should only be strong enough to start pushing us to a neutral position long term though today's run of the model suggests something more favorable. East anomalies that were previously solid in the Indian Ocean for over a year migrated east into the West Pacific on 10/1/20 and stabilized there, but are theoretically starting a slow fade while migrating east moving to the a point south of California by 5/1 as the Active Phase dislodges them and then builds over the KWGA. Theoretically the end of La Nina is near (starting on 4/16).

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

Subsurface Waters Temps
TAO Array: (4/18) Today in the far West Pacific the 28 deg isotherm line was dramatically moving eat from 177W to 172W today. The 24 deg isotherm was pushing the whole way across the equatorial Pacific and building in coverage and depth as compared to weeks prior in the East Pacific. Anomaly wise, warm anomalies +2 deg C are in the West Pacific with 1 deg anomalies reaching across the Pacific today pushing to the surface near 120W and reaching into Ecuador. No cool anomalies were indicated. The hi-res GODAS animation posted 4/13 indicates a dramatic improvement with warm anomalies moving east subsurface to 102W indicative of a Kelvin Wave poised to impact the far East Pacific and lurking just 5M below the surface at 105W. Negative anomalies in the East Pacific were all but gone with residuals getting squeezed to the surface by the Kelvin Wave. The GODAS animation appears to be 1 week behind the TAO data but also is more detailed and accurately modeled.
Sea Level Anomalies: (4/13) A dramatic improvement was occurring with sea heights near neutral (0 to -5 cms) over the entire equatorial Pacific with pockets of positive anomalies extending from the far West Pacific over the dateline and then again at 150W and solid from 130W into Ecuador. Negative anomalies were less than -5 cms along the coast of Peru and along the coast of Mexico up into California but neutral or even weakly positive from Ecuador to South Mexico. Looking at the big picture, negative anomalies had previously formed a massive triangle from Cape Mendocino to the intersection of the dateline and equator then into Southern Chile. But it was all but gone now with its remnants running parallel to the equator 10 degs north and south of it. The end of La Nina seems to be occurring now.

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: (4/17) The latest images indicate mixed slightly warm and slightly cool water was tracking west on the equator from the Galapagos to 130W. But strong cool anomalies were still present along the immediate cost of Peru out to almost the Galapagos indicative of an upwelling event. Weak warm water was further off Peru and Central America. Cool anomalies were streaming from Chile west-northwest to the dateline also feeding the main cool pool and static in strength. Overall this seems to indicate the collapse of La Nina.
Hi-res 7 day Trend (4/17): Warming temps were indicated between Ecuador over the Galapagos out to 110W, perhaps signaling the begriming of the eruption of Kelvin Wave #1. Otherwise a neutral temperature trend was occurring on the equator but with slightly warming from 110W to the dateline.
Hi-res Overview: (4/17) A generic area of warm water was west of Peru and Central America. But cold water was still evident along the immediate coast of Peru streaming off Ecuador almost to the Galapagos. But that flow was warming over the Galapagos. Also a faint area of cool water was extending from off Chile tracking west out to 140W and appears to be losing definition. A similar stream was migrating southwest from off Baja Mexico and also fading. The remaining cool core of La Nina is pushing west on the equator from 120W over the dateline but warmer than days past. La Nina appears to be in retreat.
Nino1.2 Daily CDAS Index Temps: (4/18) Today's temps were steady at -0.932 after previously bottoming out at -0.950 on 4/5. Before that temps peaked at +0.714 on 3/16. Temp previously peaked at +0.601 on 3/9 and that after a recent high of +0.100 on 2/1. Temps previously were -0.604 on 1/24. A previous peak of -0.595 occurred on 12/11. This area has been on a seesaw rising trend since early October. Temps were previously down to -2.138 on 8/13. The longterm trend has been on a slow but steady increase.
Nino 3.4 Daily CDAS Index Temps:
(4/18) Temps were steady today at -0.193 after peaking on 4/15 at -0.157 beating the recent peak of -0.185 on 3/27, after falling to-0.404 on 3/20 and that after peaking at -0.170 on 3/10, the highest in a year. Temps bottomed out at -1.654 on 11/3, rising to to -0.982 on 1/21. The previous low before that was -0.733 on 9/10. Temps were on a steady decline since 7/25 then bottomed out in late October and have been on a slow increase since.

Click for Full Sized Image Click for Full Sized Image

CFSV2 Forecast for Nino3.4 Sea Surface Temp (SST) Anomalies & Current SST Anomalies

SST Anomaly Projections
CFSv2 Uncorrected Data (4/18) - Actuals per the model indicate temps bottomed out in early Nov at -1.25 degs then rose steadily to -0.15 degs in mid-April and near neutral today. The forecast depicts temps rising to +0.05 degs in June, then starting a slow fade falling to -0.50 degs in Oct then bottoming out at -0.75 in Dec before rising slightly in Jan (-0.65 degs). This model now suggests a complete demise of La Nina starting now but then it resurging into Fall and early Winter. That seem highly unlikely at this point. But there is no sense of El Nino developing either. Of course we're still in the Spring Unpredictability Barrier, so no outcome is certain.
IRI Consensus Plume: The March 20, 2021 Plume depicts temps are at -0.50 degs today, and are to rise to -0.15 in June and stabilizing there through Nov. Most models are suggesting a moderate La Nina returning to Neutral in the late Spring of 2021.
See chart here - link.

Atmospheric Coupling (Indicating the presence of El Nino in the atmosphere driven by the ocean):
Southern Oscillation Index (SOI) (negative is good, positive bad - this is a lagging indicator) (4/18): The daily index was rising some at -1.01 today and mostly negative the last 7 days. The 30 day average was rising some to +0.46 after bottoming out at +0.26 on 4/15, after peaking at +19.51 on 1/14. The 90 day average was falling slightly at +4.44 after peaking at +15.75 on 2/23 and clearly indicative of La Nina. This index is a lagging indicator.

Pacific Decadal Oscillation
Per NOAAs index recent values: Jan 2018 +0.29, Feb -0.19, Mar -0.61, April -0.89, May -0.69, June -0.85, July -0.09, Aug -0.43, Sept -0.46, Oct -0.75, Nov -0.78, Dec -0.12, Jan 2019 -0.18, Feb -0.50 Mar -0.23, April +0.10, May +0.14, June -0.11, July +0.44, Aug -0.14, Sept +0.05, Oct -0.96, Nov -0.28, Dec +0.01, Jan 2020 -1.17, This continues to look like the warm phase of the PDO. No consistently solid negative readings have occurred since Feb 2014
The Washington/JISAO index (Jan-Dec): Jan 2018 +0.70. Feb +0.37, Mar -0.05, April +0.11, May +0.11, June -0.04, July +0.11, Aug +0.18, Sept +0.09. No real 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 

Powerlinessurf Jeff Clark Inside Mavericks

Local Interest
Stormsurf Video Surf Forecast for this week. See it Here
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