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BUOY ROUNDUP
On Monday, December 20, 2021 :

• Buoy 233 (Pearl Harbor)/Buoy 239 (Lanai)/Buoy 238 (Barbers Pt): Seas were 3.2 ft @ 8.3 secs with swell 2.2 ft @ 8.4 secs from 156 degrees. Water temp 77.0 degs (Pearl Harbor 233), NA (Lani 239), 77.7 (Barbers Pt).
• Buoy 202 (Hanalei): Seas were 10.0 ft @ 11.8 secs with swell 6.7 ft @ 8.7 secs from 32 degrees. Water temp 77.2 degs.
• Buoy 067 (San Nicholas): Seas were 4.5 ft @ 15.4 secs with swell 3.8 ft @ 15.8 secs from 305 degrees. Water temperature 59.0 degs, 58.8 (Topanga 103), 58.6 degs (Long Beach 215), 59.2 (Del Mar 153), 58.5 (Imperial Beach 155). At Harvest Buoy (071) primary swell was 2.6 ft @ 15.7 secs from 296 degrees. At Santa Monica (028) swell was 1.2 ft @ 16.1 secs from 276 degrees. At Oceanside (045) swell was 0.7 ft @ 17.1 secs from 252 degrees. Southward at Torrey Pines (Outer) (100) swell was 1.3 ft @ 16.5 secs from 274 degrees.
• Buoy 46012 (Half Moon Bay)/029 (Pt Reyes): Seas were 10.1 ft @ 14.3 secs with swell 5.2 ft @ 14.0 secs from 299 degrees. Wind at the buoy (012) was southeast at 20-25 kts. Water temp 54.0 (Pt Reyes 029), 53.4 (46026), 53.1 degs (SF Bar 142), and 53.8 (Santa Cruz 254).

See Hi-Res Buoy Dashboards (bottom of the page)

 

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/Utility Class: 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.

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

PACIFIC OVERVIEW
Current Conditions
On Monday (12/20) North and Central CA had set waves at head high to 1 ft overhead and lined up and clean but a little jumbled but not bad. Protected breaks were shoulder to head high and lined up and clean but soft. At Santa Cruz surf was waist high and mushed and pretty torn up from south-southeast wind. In Southern California/Ventura waves were flat and clean with no wind. Central Orange County had a few thigh high waves breaking nearly on the beach and clean. South Orange County's best summertime breaks were flat to knee high and clean and weak. North San Diego had sets at knee high and weak and soft but clean. Hawaii's North Shore was getting northeast windswell with waves chest to head high and lined up but also crossed up and a little ruffled from northeast trades. The South Shore was knee to waist high and clean. The East Shore was getting north windswell at head high or so and really chopped from brisk northeast trades.

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

Meteorological Overview
On Monday (12/20) North and Central California was getting small swell from a gale that developed off North Japan Tues-Wed (12/15) producing 29 ft seas aimed east but faded before reaching the dateline. A very weak system was falling south off California Sun-Tues (12/21) producing up to 18 ft seas aimed south and not aimed well at the state. But then nothing till a stronger system develops in the Northern Gulf falling south Thurs-Sat (12/25) producing up to 21 ft seas aimed south and southeast. And maybe a small system to develop over the dateline Sat (12/25) producing 36 ft seas aimed east but not moving over the dateline. The Central Pacific is locked down by high pressure leaving only the edges available for gale production.

See all the details below...

 

SHORT- TERM FORECAST
Current marine weather and wave analysis plus forecast conditions for the next 72 hours

North Pacific

Overview
Jetstream
On Monday (12/20) the jet was pushing east off Japan with winds to 180 kts but splitting heavily on the dateline with the northern branch ridging hard north up into the Bering Sea then tracking into North Canada before falling southwest out off British Columbia forming a backdoor trough off of California being fed by 120 kts winds offering some support for low pressure development before turning east and northeast pushing back inland over South Oregon. Over the next 72 hours starting Tues (12/21) the backdoor trough is to get fully cutoff with jet stream energy pushing inland over North CA later in the day with winds to 150 kts on Wed (12/22) offering weather and more energy spilling south just off the US West Coast starting to generate a new trough but very pinched. Beyond 72 hours starting Thurs (12/24) more of the same is forecast in the west with the jet pushing off Japan at 170 kts splitting on the dateline and tracking up into the North Bering Sea before starting to again fall south through the Northern Gulf cutting out a new trough with it's apex falling off California on Sat (12/25) and again turning into more of a a backdoor trough on Sun (12/26) being reinforced with more jetstream energy into Mon (12/27). At that time winds are to be building to 220 kts pushing off Japan to the dateline but the split point is to hold. Local weather is definitely in the mix for California, with a constant weak jetstream flow over the state centered roughly over the San Francisco area and the Central Sierra starting late Mon (12/20) continuing through Mon (12/27).

Surface Analysis
On Monday (12/20) swell from a gale off Japan was hitting California (See Japan Gale below). And small swell from a gale that formed on the dateline was radiating towards Hawaii (see Tiny Dateline Gale below). And windswell was in the mix too from a low pressure system off California (see Local CA Low Pressure System below).

Over the next 72 hours another low pressure system is forecast for the Northeastern Gulf on Wed AM (12/22) producing a fetch of 30 kt north winds and seas building from 17 ft at 51N 137W aimed south. In the evening 25 kt north winds are forecast off Vancouver Island falling south producing 16 ft seas at 48N 134W aimed southeast. Fetch fading from there.

A better defined fetch of northwest winds at 40 kts is to set up in the far Northern Gulf on Thurs AM (12/23) starting to get traction. In the evening the fetch is to build at 35-40 kts extending south to a point off Vancouver Island with seas 20-22 ft at 51N 140W aimed southeast. On Fri AM (12/24) 30-35 kt northwest winds to be off Oregon with 23 ft seas at 47N 134W aimed southeast. In the evening 30 kt northwest winds to fall off North CA with seas 19 ft at 41N 133W aimed southeast. On Sat AM (12/25) fetch is to be fading from 30 kts off San Francisco with seas fading from 19 ft at 39N 135W aimed southeast. Fetch to dissipate from there. Something to monitor.

 

Japan Gale
A gale developed off Japan on Mon AM (12/13) producing west winds at 40+ kts starting to get traction on the oceans surface with seas building from 25 ft at 40N 151E aimed east. In the evening 40-45 kt west winds were tracking off the coast with seas 29-30 ft at 42N 159E aimed east. On Tues AM (12/14) 35 kt west winds were positioned half way to the dateline lifting north generating 26 ft seas at 41.5N 166.5E aimed east. In the evening fetch is to be fading from 30-35 kts from the west still lifting north off Kamchatka and making no east headway with 26 ft seas fading at 48.5N 168.5E aimed east. Fetch fading out on Wed AM (12/15) with 24 ft seas fading just south of the Western Aleutians at 50N 172E aimed east. The gale is to be gone after that. Perhaps some swell for Hawaii and inconsistent energy radiating into California with luck.

North CA: Swell holding on Mon (12/20) at 2.8 ft @ 14.15 secs (4.0 ft) with local windswell intermixed. Swell Direction: 296 degrees.

 

Tiny Dateline Gale
A small gale developed on the dateline on Thurs PM (12/16) producing 45+ kt northwest winds over a tiny area aimed southeast with seas 26 ft at 36N 173E. On Fri AM (12/17) northwest winds held at 45 kts with seas 25 ft seas at 36N 179E aimed southeast. Fetch fading in the evening at 35 kts from the north with seas fading from 22 ft at 32N 180W. Some small swell to result for Hawaii.

Oahu: Expect swell and windswell mix to arrive on Tues (12/21) building to 6.0 ft @ 10 secs later (6.0 ft). Swell peaking Wed AM (12/22) at 6.0 ft @ 11 secs (6.5 ft). residuals on Thurs (12/23) fading from 4.6 ft @ 10-11 secs (4,5 ft). Swell Direction: 312 degrees

 

Local CA Low Pressure System
A low pressure system developing off North CA on Sun AM (12/19) producing 30-35 kt north winds and seas building from 18 ft at 41N 144W aimed southeast. Fetch held at 30-35 kts from the north in the evening well of North CA with 18 ft seas at 38N 142W aimed south. On Mon AM (12/20) north winds were fading some from 30 kts with seas fading from 17 ft at 38N 140W aimed south. Perhaps secondary fetch is to form off Cape Mendocino (North CA) on Mon PM (12/20) producing north winds at 35-40 kts and seas building from 18 ft at 42N 134W aimed south. On Tues AM north winds to be 35 kts with seas 19 ft at 42N 138W aimed south. Fetch is to fade in the evening from 30 kts pushing west off the coast with sea fading from 17 ft at 42N 137W aimed south. Windswell to result.

North CA: Expect sideband swell arrival on Tues (12/21) at 2.4 ft @ 12-13 secs (3.0 ft). More windswell on Wed (12/22) at 2.2 ft @ 11-12 secs (2.5 ft). Swell Direction: 300 degrees

 

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

 

Tropical Update
No tropical systems of interest are forecast.

California Nearshore Forecast

• Tues (12/21) a front is to be along the coast of North and Central CA producing south winds 20-25 kts for North CA and south wind 15-20 kts for Central CA down to Monterey Bay and 10 kts down to Pt Conception. In the afternoon south winds to be fading from 15-20 kts for all of North CA and 15 kts for Central CA to Monterey Bay. Rain developing for all of North CA mid- AM building over Central CA late afternoon into the evening down to Big Sur. Snow developing for Tahoe northward in the evening.
• Wed (12/22) the low is to fade with south winds 20 kts for Cape Mendocino and 15 kts down to the Golden Gate with south wind 5-10 ks for Central CA. Southwest winds build in the afternoon at 2025 kts for Cape Mendocino and 15-20 kts from Pt Reyes northward. Light winds are forecast south of there. Rain between Big Sur and Bodega Bay early building down to Santa Barbara County in the afternoon. Steady modest snow focus on Tahoe during the day building some in the evening.
• Thurs (12/23) morning west winds to be 15 kts for Cape Mendocino with light west winds 5-10 kts southward to Monterey Bay. South winds are forecast at 5-10 kts south of there. In the afternoon northwest winds are forecast at 10-15 kts from all of North CA down to the Golden gate and 10 kts south of there to Pt Conception. Light rain for all of CA early holding all day while building over all of Southern CA. Heavy snow for the Sierra all day fading some in the evening.
• Fri (12/24) morning southwest winds to be 20 kts for Cape Mendocino and light from the Golden Gate southward. In the afternoon a front is to be falling south with west winds down to Pt Reyes and the leading edge of the front over the Golden Gate with south winds 20 kts there and south winds 10-15 kts down to Pt Conception. Rain for North CA early and light rain to Pigeon Pt early building down to Big Sur in the afternoon and also into Southern CA and covering the entire state in the evening. Light snow focused on Tahoe early building down the entire Sierra in the afternoon and turning heavy for Tahoe overnight.
• Sat (12/25) northwest winds to be 10 kts for Cape Mendocino and 15-20 kts from Pt Arena south to Pt Conception. In the afternoon northwest winds are forecast at 10-15 kts for North CA and west to southwest at 20 kts for Pt Reyes south to Pt Conception. Rain for the entire state early holding all day but thinning for Southern CA later. Heavy snow for the Tahoe early turning moderate late AM and steady moderate snow for the whole Sierra holding all day building to almost heavy status in the evening.
• Sun (12/26) northwest winds set up at 15 kts early for all of North and Central CA down to LA County. In the afternoon light winds are forecast for all of North and Central CA and northwest 10-15 ks for Southern CA. Light rain for all of the state early slowly breaking up over South and Central CA late but holding for North CA. Moderate snow for the Sierra early fading and isolated to Tahoe in the afternoon.
• Mon (12/27) AM another front sets up with southwest winds 20 kts for all of North CA with 15 kt southwest winds down to Monterey Bay and south winds 10 kts south of there. In the afternoon southwest winds are forecast at 10-15 kts for Cape Mendocino with south winds 20-25 kts from Pt Reyes south to Pt Conception. Rain building in solid for all of North CA early down to Santa Cruz pushing south to Morro Bay in the afternoon. Light snow for Tahoe early turning heavy in the afternoon.

Total snow accumulation for the next 10 days respectively for Squaw Valley, Sugar Bowl, Kirkwood and Mammoth at 139, 150, 124, and 83 inches starting 12/21 late evening and going non-stop through Thurs 12/30.

Freezing level building to 8,5000 ft today 12/20 through 12/21 then steadily falling to the 3,500 ft level late on 12/23 falling then falling to 3,000 ft on 12/26 and holding for the foreseeable future. It looks like steady precip and cold temps coming but no deluge.

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Tioga Pass/Pacific Crest Trail intersection forecast: Temps - Freeze Level (more here - scroll down to 'Resort Snow Forecasts>Central CA or North CA Caltrans & Backcountry')

Snow Models: http://www.stormsurf.com/mdls/menu_snow.html (Scroll down for resort specific forecasts). Updated!

 

South Pacific

Overview
Surface Analysis
No swell producing fetch has occurred of is forecast.

Over the next 72 hours no swell producing fetch of interest is forecast.

 

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

 

QuikCAST's

 

LONG-TERM FORECAST
Marine weather and forecast conditions 3-10 days into the future

North Pacific

Beyond 72 hours starting Fri AM (12/24) a gale is to start building on the dateline producing a fetch of 35-40 kt northwest winds and seas building. In the evening winds to build to 45-50 kts from the northwest over a small area stationary just west of the dateline with seas building to 30 ft at 36N 175E aimed southeast. On Sat AM (12/25) northwest winds to hold at 45-50 kts with seas building from 35 ft at 39N 173E aimed southeast. Fetch is to fade in the evening from 35 kts with seas fading from 26 ft at 37N 175E aimed southeast. Maybe some swell to result for primarily Hawaii assuming this system even forms.

 

South Pacific

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

 

MJO/ENSO Forecast

 

La Nina Possibly Peaking as SubSurface Pool Discharges - Active MJO In Control
Summary - Cool subsurface water volume peaked under the equatorial Pacific on 10/15/21, beating last years volume, and now is discharging to the surface while fading and easing east. A stronger than expected Active Phase of the MJO is producing west anomalies forecast to hold over the KWGA into mid January filling 75% of the KWGA as the low pressure bias slowly builds in from the west. A return to a more normal cadence of Active and Inactive MJO phases is starting now. It appears surface water temps have bottomed out. With that it seems the the peak of this years La Nina event is already behind us. But the atmosphere will be slow to respond.

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: In 2019 warm equatorial 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 evolved into La Nina, with it fully developing through July 2020. A slow dissolving of La Nina started in March 2021 with 2 Kelvin Waves sweeping east and arriving over the Galapagos in June. Weak warming set up over the equator with no cool waters present. NOAA declared La Nina dead.

LONG-RANGE PACIFIC STORM AND SWELL GENERATION POTENTIAL FORECAST

Fall /Winter 2021-2022 = 3.0 (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 was assumed that the moderate La Nina from the Winter of 2020/2021 was on the wane and that a return to neutral ENSO state would set up over the Pacific Basin through the summer of 2021. But La Nina is making a strong return as we move into the end of Sept much like what the CFS model suggested would happen. So at this point we are speculating that the CFS model will verify and that a full double dip La Nina pattern will take hold as we move into November with this second La Nina dip being nearly as strong as the previous one. But a quick fade is forecast as we move into late Fall (Nov) with the CFS predicting a return to a neutral wind anomaly pattern at that time and the low pressure bias making headway in to the KWGA in early Dec. Still it will take some time for the atmosphere to fully respond, resulting in a less than normal swell production forecast especially for Fall into early Winter. But by later in Jan 2022 perhaps a return to a more normal pattern might take hold. As a result a somewhat reduced number of storm days and storm intensity is expected Oct-Dec, resulting in a below normal level of swells, with swell being below normal duration and period. But by later Winter (2022), the number of storm days, intensity and duration of those storms should start improving as La Nina fades out. The status of the PDO is not known, though it appears to be returning to at least a neutral state, rather than the warm phase as previously projected thereby having no significant positive or negative effect on the long term outlook.

KWGA/Equatorial Surface Wind Analysis (KWGA - Kelvin Wave Generation Area - The area 5 degrees north and south of the equator from 170W to 135E)
Analysis (TAO Buoys): As of (12/19) 5 day average winds were strong from the east over the Eastern equatorial Pacific and strong east over the Central Pacific and moderate east over the KWGA. Anomalies were light east over the East equatorial Pacific and modest east over the Central Pacific and moderate east over the KWGA. (Note: These are 5 day average winds, versus realtime, so they lag what is happening today (by about 2.5 days).
1 Week Forecast (GFS Model): On (12/20) east anomalies were modest over the entire KWGA. The forecast calls for moderate east anomalies slowly fading and gone by 12/21 with west anomalies trying to build in and slowly filling the entire KWGA by 12/22 and holding through 12/24. East anomalies to rebuild on the dateline on 12/25 holding through the end of the model run on 12/27 at modest strength.

Kelvin Wave Generation Area wind monitoring model: West and East

MJO/WWB/Wind Projections:  
OLR Models: (12/19) A moderate Active MJO signal was filling the KWGA today. The statistical model suggests the Active Phase is hold strength while slowly moving east through day 15 of the model run and just about east of the dateline centered more over the Central Pacific. The dynamic model projects the same as the statistical model but not moving east as fast, with the Active Phase well centered over the dateline on day 15 of the model run and strong.
Phase Diagrams 2 week forecast (ECMF and GEFS): (12/20) The statistical model depicts the Active Phase was weak over the West Pacific and is forecast tracking over Africa at day 15 of the model run and very weak. The dynamic model suggests the Active Phase moving to the East Pacific and holding at moderate strength on day 15 of the model run. It's been a long time since we've seen this.
40 day Upper Level Model (assumed to be a statistical mode and 1 week ahead of what is occurring at the surface): (12/19) A modest Active MJO signal (wet air) was over the Central Pacific today with a new pulse building over the West Pacific. The forecast indicates the combination of the two are to track east pushing into Central America 1/18. The Inactive Phase (dry air) is to start developing over the West Pacific on 1/3 and weak moving to the East Pacific at the end of the model run on 1/28. A new Active Phase (wet air) is forecast starting to build over the far West Pacific on 1/23 moving east from there and pretty solid.
4 Week CFS Model (850 mb wind): (12/19) This model depicts the Active Phase was weakening some over the Central KWGA today with west anomalies rebuilding over the entirety of the KWGA. The forecast indicates the Active MJO signal tracking through the KWGA and exiting east of it on on 1/8 positioned just west of the dateline but west are to be building from today forward and strong on the dateline 12/27-1/6 then fading but still holding control of the eastern half of the KWGA through the end of the model run on 1/16. East anomalies are to develop in the far West KWGA on 12/26 slowly building in coverage but never pushing east of 150E.
3 Month CFS Model (850 mb wind): (12/20 - using the 5th ensemble member - the mean of the 4 individual members which are all from the 00Z run - 1 run per day): Today the Active Phase of the MJO was filling the KWGA with weak west anomalies filling the KWGA. The forecast indicates the Active MJO is to continue moving over the KWGA through 1/7 with west anomalies filling the KWGA during that window and into Jan 18 and strong 12/29-1/7. The Inactive Phase is to follow 12/22-2/16 but not particularly strong with weak east anomalies building over the KWGA peaking on the dateline on 1/21-2/14. A modest Active Phase is to develop on 1/29 pushing east through the KWGA through 3/17 with modest west anomalies during that window. An Inactive Phase is to follow starting 3/15 through the end of the model run on 3/19. The low pass filter indicates a high pressure bias with 2 contour lines was centered over the dateline and is to hold till 1/19, then easing east. A second contour is to fade out on 1/5. A broad single contour low pressure bias is now established centered over the Maritime Continent at 100E with it's leading edge at 125E and barely in the KWGA and is forecast starting to move east further into the KWGA to 150E on 1/29 filling 50% of the KWGA and building further east to nearly the dateline at the end of the model run. Today a solid east anomaly pattern that has been in control of KWGA since early July is being significantly challenged by west anomalies from the Active Phase of the MJO. A return to a more normal MJO alternating pattern is forecast moving forward. This could signal the demise of La Nina as we get deeper into Winter. That said, there is only one more Active MJO forecast for this winter, in the late-Jan to early March timeframe.

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

Subsurface Waters Temps
TAO Array: (12/20) Today in the far West Pacific the 29 degree isotherm was pushing east to 167E. The 28 deg isotherm line was steady at 179E. The 24 deg isotherm was steady at 125W. Anomaly wise, warm anomalies +3 deg C were building with their leading edge at about 165W. All sensors are down at 140W. Cool anomalies were steady at -1 to -3 degs C down 150 meters at 150W and tracking east while rising near the surface near 95W. No Kelvin Waves were obvious and cool water was in control in the east at depth but definitely less of a force than weeks and months past. The hi-res GODAS animation posted 12/14 indicates no warm water east of 170W at depth with a bubble of cold water at -3C below normal east of there (where the sensors are inoperable) extending upward to the surface off Ecuador but with noticeably less intensity than weeks past and definitely losing ground. The GODAS animation appears to be 1 week behind the TAO data but also is more detailed and accurately modeled.
Sea Level Anomalies: (12/14) Sea heights were negative over the East equatorial Pacific from Ecuador to 175W at -5 to -10 cms with only two small pockets of -15 cms anomalies at 95W and 140W. -10 cms anomalies cover a broad area between 85W to 155W. All positive anomalies were limited from 170E and points west of there at 20 to 25 cms. A warm water 'horseshoe' pattern is well developed in the West Pacific. La Nina made a return and stronger than last year, but now appears to be in decline, at least from the subsurface water temp perspective. Per the Upper Ocean Heat Anomaly Histogram La Nina subsurface cold temperatures peaked in coverage in mid-Oct, far broader than last year (-2.5 degs C), but as of 12/14 that coverage is collapsing centered at 100W with the coolest anomalies (-2.5 degs) gone and -1.5 deg anomalies shrinking fast from the west and east bordered between 108W and 90W. It appears a cold water Kelvin Wave (upwelling Kelvin Wave) is erupting just west of the Galapagos. But a second little bubble of cooler water was developing at 145W.

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 Qualitative Analysis: (12/19) The latest images depict a broad stream of cool water on the equator and extending south from Chile up to Peru then turning west and peaking from the Galapagos east to 110W then weaker but still solid west of there to at least the dateline. A classic La Nina pattern was evident. But a pocket of warming water was depicted at 130W and a few pixels of warming were fading along the coast of Chile. An area of warm water just north of the equator was fading from Ecuador west to 140W and up along Central America into Southern Baja. Overall this indicates the return of cold water temps in the Central Equatorial Pacific indicative of La Nina.
Hi-res 7 day Trend (12/19): Temps were warming along Chile and Peru and building compared to days past and warming in a string between the Galapagos to 135W and pretty solid at 80W-125W. A few small pockets of cooling were interspersed. A cold water Kelvin Wave is erupting at the surface in the East equatorial Pacific resulting from the discharge of subsurface water below it.
Hi-res Overview: (12/19) No real change - A broad stream of cooler than normal water was aligned on the equator from Ecuador to 110W then weaker but still solid out to 160E. Cooler than normal waters were also south of that line down to 20S. Warmer than normal waters were limited to a line north of the equator up to Mexico and along the US Coast up to Pt Conception. A previous cool outflow from South California southwest to the a point over Hawaii's Big Island was gone. La Nina is solid but not building anymore focused over the equatorial Central Pacific.
Nino1.2 Daily CDAS Index Temps: (12/20) Today's temps were rebounding some at -1.859 after falling hard to -1.954 on 12/18, the lowest this year so far. Previously temps rose to -1.432 on 11/29 and that after dropping on 11/24 at -1.700, the lowest in months after previously toggling steady at about -0.6 degs from mid Aug to Oct 6, then falling from there. Before that temps were toggling around neutral 6/13-8/5 except for one dip to -0.411 on 7/8. Prior to that temps peaked on 3/16 when they briefly hit +0.714 degs. Last year temps bottomed out at -2.138 on 8/13/20. The longterm trend has been steadily downward.
Nino 3.4 Daily CDAS Index Temps: (12/20) Today temps were creeping up at -0.869 after rising to -0.685 on 11/9, and that after bottoming out at -1.08 on 11/2, the lowest in a year. Prior to that temps had been in a freefall starting from the -0.175 range in early Sept. Before that temps peaked up at 7/1 +0.332, the highest in a year. Temps previously had been steady near -0.222 since early March. Temps bottomed out at -1.654 on 11/3/2020.

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

SST Anomaly Projections
CFSv2 Uncorrected Data (12/18) - Temps rose in early Nov 2020 after bottoming out at -1.25 degs, up to -0.01 degs in mid-June then fading to -0.3 degs through Aug and to -0.75 degs in mid Oct and -1.0 degs in mid-Nov. The forecast indicates temps to continue a steady fall dropping down to -1.30 in mid Jan 2022 then quickly pushing up to +0.00 degs in July 2022. This model suggests a return of La Nina conditions and strongly so this Fall and Winter. There is no indication that El Nino will develop. The PDF Corrected forecast suggests the same with temps falling to -1.25 degs in mid-Jan starting to rise slowly after mid-Jan 2022. At this point that is as good a guess as any. And the model has been unwavering in this projection for months now.
IRI Consensus Plume: The Dec 20, 2021 Plume depicts temps are at -1.032 degs today and have bottomed out. They are to warm to -0.47 degrees in March, then rising to -0.00 degs in July and neutral after that. A solid return of La Nina is expected peaking about now then warming thereafter.
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):
Today (12/20) the daily index was negative at -9.81. The trend has been towards positive readings with previous notable peaks were at +30.98 on 11/26, +36.90 on 9/28, +27.75 on 9/13 and +37.86 on 7/15.
The 30 day average was falling some at +11.50 after previously falling to +6.06 on 11/6 after peaking at +11.58 on 10/22. Before that it fell to -3.36 on 6/22, the lowest in a year. It peaked at +19.51 on 1/14.
The 90 day average was falling some at +9.67 today after peaking at 10.22 on 12/10, falling to +7.10 on 11/1. It previously peaking on 9/21 at +9.80 after falling to it's lowest point in a year on 6/9 at +1.06. The 90 day average peaked at +15.75 on 2/23 (clearly indicative of La Nina then). This index is a lagging indicator but suggest La Nina is returning.

Pacific Decadal Oscillation
The PDO theoretically turned from a 16 year negative run (Jan 98-Feb 2014) in early 2014 and was positive till Dec 2019, but has been negative every since, driven by recent La Nina conditions. In May-July 2021 it was the most negative its been in the -1.80 to -2.04 range since Sept 2012 (-2.99). 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'). If anything it appears more likely we are still in the cool phase of the PDO.

See imagery in the ENSO Powertool 

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Powerlines

Jeff Clark

Inside Mavericks

Local Interest
Stormsurf Video Surf Forecast for this week. See it Here
For automatic notification of forecast updates, subscribe to the Stormsurf001 YouTube channel - just click the 'Subscribe' button below the video.

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NBC News - Climate Change and Surfing: https://www.nbcnews.com/mach/science/climate-change-good-surfing-other-sports-not-so-much-ncna1017131

Mavericks & Stormsurf on HBO Sports with Bryant Gumbel https://www.youtube.com/watch?v=luQSYf5sKjQ

Pieces Featuring Stormsurf:
http://www.bloomberg.com/video/how-to-predict-the-best-surfing-waves-EsNiR~0xR5yXGOlOq2MqfA.html
http://www.cbsnews.com/videos/surfs-up-for-mavericks-invitational-in-calif/

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.

Surf Height-Swell Height Correlation Table