El Nino coming, but Cool Phase PDO predicted for North Pacific

SilverFly

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Cool nearshore waters predicted off PNW coast this summer, in spite of what appears to be a strong El Nino in the works.


Discussion: During Q1/2023 a persistent upper trough on the U.S. West Coast has caused amplified cooling of ocean waters off the West Coast of North America (Fig. 1). The cool phase of the Pacific decadal oscillation (-PDO) has intensified. Marine heat wave NEP22A has shifted well to the west and to the north and northwest of Hawaii. The cool California Current continues to arc southwestward bringing cool waters toward the Nino34/Nino4 SSTA regions (Fig. 2). In fact, the cool SSTA in this southwestward trajectory to the west of Baja California has intensified during the past 2 weeks (Fig. 3). Meanwhile, the Nino12 SSTA region off the northwest coast of South America has surged to a very warm daily SSTA of +2.44C. Daily southern oscillation (SOI) has bounced to +2.39 and trade winds have increased in the east-central equatorial Pacific. A Madden Julian oscillation (MJO) pulse is forecast to generate during the next 10 days which should reverse SOI and ease trade winds. But for now, prohibitive El Nino warming off the northwest coast of South America is blocked from westward progression by incoming col waters from the north.
 

SilverFly

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If I'm reading this correctly, we could be in for a similar offshore season to last year. In 2022, my inner amateur internet oceanographer, was hoping the warm SST anomaly in the cental North Pacific would bring us more Opah than the usual onesies/twosies. While some opah were caught, I don't think anyone was expecting this severely lost Kona resident (the fish, not Eamon) :155857.jpeg
This is how the same anomaly (circled in green) is shaping up this year:
Screenshot_20230526_085220_Chrome.jpg
 

Cabezon

Sculpin Enterprises
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El Nino (aka, ENSO = El Nino Southern Oscillation) vs. La Nina oceanographic conditions are associated with specific weather patterns (see here) around the world, including the PNW. Typically, La Nina brings wetter, colder weather to the PNW and El Nino brings drier, warmer weather. We have been experiencing La Nina conditions for the last three years (a "triple-dip", atypical for a single state to last this long). This last winter (last several weeks excepted perhaps) seemed to fit the prediction as we generally experienced colder and wetter conditions. But this association is NOT absolute. For example, La Nina conditions typically leave California dry (and El Nino conditions are associated wet weather in CA), but this winter was a banner year for rain in California - north and south.
And we would have expected that the waters off Washington last summer would have been cooler due to La Nina. And that would have influenced both the tuna population off Washington (if cooler, then lower) and the likelihood of encountering exotics (if cooler, then fewer). But a number of warm-water exotics were caught last summer in what was a solid tuna year (especially compared to 2021).
One of the major drivers of primary production off the Washington coast is upwelling. Summer winds from the north along the coast push surface waters offshore (Eckman transport). Cooler, nutrient-enriched waters from below move to the surface to replace the warmer, nutrient-poor waters that have been pushed offshore. Light plus nutrients equals bursts of primary production. This is the base of the food web that coastal salmon populations. Interestingly, here is a quote from a report by the Climate Impact Group at UW on the relationship between El Nino and coastal upwelling: "Warm phases of both ENSO (El Niño) and the Pacific Decadal Oscillation (PDO) are correlated with a delay and shortening of summer upwelling along the Pacific Northwest coast." Presumably, La Nina conditions would mean a longer and stronger summer upwelling along the PWN coast. The impacts of El Nino are predicted to arrive this summer and it will be interesting to see what this means for coastal upwelling (and the food base for salmonids).
Steve
 

RRSmith

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While fun to talk about, I honestly think it will be difficult to predict how this summer/early fall's offshore season will go. ENSO/California Current effects are part of it but we've found that so much of it has to do with meteorology and the steering winds that help push the warm water within range of sport boats. I can confidently report that past 8 days, long range forecasts become voodoo science.

When I was a member of Humboldt Area Saltwater Anglers, one of the members was a NOAA guy in charge of the observer program off the West Coast. He told me that opah are almost always here in late summer/fall. Back when the drift gillnet swordfish fishery was going on, opah were reasonably common in the landings.
 

Zak

Legend
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El Nino (aka, ENSO = El Nino Southern Oscillation) vs. La Nina oceanographic conditions are associated with specific weather patterns (see here) around the world, including the PNW. Typically, La Nina brings wetter, colder weather to the PNW and El Nino brings drier, warmer weather. We have been experiencing La Nina conditions for the last three years (a "triple-dip", atypical for a single state to last this long). This last winter (last several weeks excepted perhaps) seemed to fit the prediction as we generally experienced colder and wetter conditions. But this association is NOT absolute. For example, La Nina conditions typically leave California dry (and El Nino conditions are associated wet weather in CA), but this winter was a banner year for rain in California - north and south.
And we would have expected that the waters off Washington last summer would have been cooler due to La Nina. And that would have influenced both the tuna population off Washington (if cooler, then lower) and the likelihood of encountering exotics (if cooler, then fewer). But a number of warm-water exotics were caught last summer in what was a solid tuna year (especially compared to 2021).
One of the major drivers of primary production off the Washington coast is upwelling. Summer winds from the north along the coast push surface waters offshore (Eckman transport). Cooler, nutrient-enriched waters from below move to the surface to replace the warmer, nutrient-poor waters that have been pushed offshore. Light plus nutrients equals bursts of primary production. This is the base of the food web that coastal salmon populations. Interestingly, here is a quote from a report by the Climate Impact Group at UW on the relationship between El Nino and coastal upwelling: "Warm phases of both ENSO (El Niño) and the Pacific Decadal Oscillation (PDO) are correlated with a delay and shortening of summer upwelling along the Pacific Northwest coast." Presumably, La Nina conditions would mean a longer and stronger summer upwelling along the PWN coast. The impacts of El Nino are predicted to arrive this summer and it will be interesting to see what this means for coastal upwelling (and the food base for salmonids).
Steve
Thank you for this very informative post!
 

iveofione

Life of the Party
Forum Supporter
El Nino (aka, ENSO = El Nino Southern Oscillation) vs. La Nina oceanographic conditions are associated with specific weather patterns (see here) around the world, including the PNW. Typically, La Nina brings wetter, colder weather to the PNW and El Nino brings drier, warmer weather. We have been experiencing La Nina conditions for the last three years (a "triple-dip", atypical for a single state to last this long). This last winter (last several weeks excepted perhaps) seemed to fit the prediction as we generally experienced colder and wetter conditions. But this association is NOT absolute. For example, La Nina conditions typically leave California dry (and El Nino conditions are associated wet weather in CA), but this winter was a banner year for rain in California - north and south.
And we would have expected that the waters off Washington last summer would have been cooler due to La Nina. And that would have influenced both the tuna population off Washington (if cooler, then lower) and the likelihood of encountering exotics (if cooler, then fewer). But a number of warm-water exotics were caught last summer in what was a solid tuna year (especially compared to 2021).
One of the major drivers of primary production off the Washington coast is upwelling. Summer winds from the north along the coast push surface waters offshore (Eckman transport). Cooler, nutrient-enriched waters from below move to the surface to replace the warmer, nutrient-poor waters that have been pushed offshore. Light plus nutrients equals bursts of primary production. This is the base of the food web that coastal salmon populations. Interestingly, here is a quote from a report by the Climate Impact Group at UW on the relationship between El Nino and coastal upwelling: "Warm phases of both ENSO (El Niño) and the Pacific Decadal Oscillation (PDO) are correlated with a delay and shortening of summer upwelling along the Pacific Northwest coast." Presumably, La Nina conditions would mean a longer and stronger summer upwelling along the PWN coast. The impacts of El Nino are predicted to arrive this summer and it will be interesting to see what this means for coastal upwelling (and the food base for salmonids).
Steve
Some serious esoteric jargon in play here!
 
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