It is too soon to tell. Moreover, the TYPE of El Nino it will be is yet to be determined. There isn't a strong enough signature in regions 3, 3.4 or 4 to determine whether the core of the anamoly will be east or west based. Studies are showing this has a significant role in affecting the sensible weather in the Western U.S.
Wait.
Is that what determines whether a Nino snowpack will be ok/mediocre or just plain suck? Look at this:Quote:
Originally Posted by lionelhutz
http://www.wrh.noaa.gov/pih/PDF/ElNi...SepOutlook.pdf
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
4 October 2012
ENSO Alert System Status: El Niño Watch
Synopsis: Borderline ENSO-neutral/ weak El Niño conditions are expected to continue into Northern Hemisphere winter 2012-13, possibly strengthening during the next few months.
During September 2012, the trend towards El Niño slowed in several key oceanic and atmospheric indicators. However, the Pacific basin reflects borderline ENSO-neutral/ weak El Niño conditions. Equatorial sea surface temperatures (SST) remained elevated across the Pacific Ocean (Fig. 1), although anomalies decreased during the month as indicated by weekly index values in the Niño regions (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) anomalies also weakened (Fig. 3), but continued to show large regions of above-average temperatures at depth across the equatorial Pacific (Fig. 4). Interestingly, low-level westerly wind anomalies were evident over the equatorial western Pacific Ocean (Fig. 5), which may portend possible strengthening of the subsurface anomalies in the coming months. Despite these winds, the atmosphere was still largely ENSO-neutral, as reflected by the Southern Oscillation index and near-average upper-level and lower-level winds across much of the Pacific. Tropical convection increased near the Date Line, which is consistent with weak El Niño conditions, but also remained elevated over eastern Indonesia, which is further westward than expected (Fig. 6). Thus, the atmosphere and ocean indicate borderline ENSO-neutral/ weak El Niño conditions.
Compared to the past few months, the chance is reduced for El Niño to develop during Northern Hemisphere fall/winter 2012-13 (see CPC/IRI consensus forecast). Due to the recent slowdown in the development of El Nino, it is not clear whether a fully coupled El Niño will emerge. The majority of models indicate that borderline ENSO-neutral/ weak El Niño conditions will continue, and about half suggest that El Niño could develop, but remain weak (Fig. 7). The official forecast therefore favors the continuation of borderline ENSO-neutral/ weak El Niño conditions into Northern Hemisphere winter 2012-13, with the possibility of strengthening during the next few months.
Temp prediction for Nov-Jan as of 9/20/2012 for those of us that like pikchas:
http://www.cpc.ncep.noaa.gov/product...off02_temp.gif
Precip Pikcha, same dates:
http://www.cpc.ncep.noaa.gov/product...off02_prcp.gif
PNW sad pants.
Temp prediction for Nov-Jan as of 9/20/2012 for those of us that like pikchas:
http://www.cpc.ncep.noaa.gov/product...off02_temp.gif
Precip Pikcha, same dates:
http://www.cpc.ncep.noaa.gov/product...off02_prcp.gif
PNW sad pants but increases the reasons for a return to Taos:
JFM prepic prediction:
http://www.cpc.ncep.noaa.gov/product...off04_prcp.gif
Snow in socal this week at 7000 feet
Earliest I can remember in 10 years
El Nino watch 2012 was just officially cancelled by the NOAA climate prediction center! ENSO neutral likely for now with some models now pointing towards a cooling trend.
^^ but it also went back to a positive AO, which to me might be just like last year. i guess we'll see.
^^^ certainly bad for temps..... Prolonged cold weather plzzzz
Except that, unlike last year, the polar vortex will be interacting with a storm track that is predicted to be farther south than last years Nina storm track. Last year, sure, it often seemed that jet stream was anchored in AK and BC. It worked its way south to the Tetons enough times to give us a 400+ inch season but rarely went any further south. But, last year, it was the combined effect of weak polar pressure and a jet stream that was already set up in the northerly latitudes. Perhaps, if the jet stream is setting up for its typical Nino southerly track across the four corners/southern rockies area, then a weak polar force might combine to pull the storm track back north to the central rockies.Quote:
Originally Posted by goldenboy
Been on vacation so just now getting this up...
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
8 November 2012
ENSO Alert System Status: Not Active
Synopsis: ENSO-neutral is favored through the Northern Hemisphere winter 2012-13.
During October 2012, the Pacific Ocean continued to reflect borderline ENSO-neutral/ weak El
Niño conditions. Equatorial sea surface temperature (SST) anomalies increased across the Pacific Ocean
during the latter half of the month (Fig. 1), which was also reflected in the Niño indices (Fig. 2). The
oceanic heat content (average temperature in the upper 300m of the ocean) anomalies also increased
slightly (Fig. 3) in association with the downwelling oceanic Kelvin wave (Fig. 4). While the subsurface
and surface Pacific Ocean has recently warmed, the tropical atmosphere remained largely consistent with
ENSO-neutral. Upper-level and lower-level winds were near average, and the strength of anomalous
convection decreased over the past month (Fig. 5). Thus, the atmosphere and ocean continue to indicate
borderline ENSO-neutral/ weak El Niño conditions.
Relative to last month, the SST model predictions more strongly favor ENSO-neutral, although
remaining above-average in the Niño-3.4 region through the Northern Hemisphere winter 2012-13 (Fig.
6). While the tropical ocean and atmosphere may resemble a weak El Niño at times, it is now considered
less likely that a fully coupled El Niño will develop. Therefore, the previous El Niño Watch has been
discontinued as the chance of El Niño has decreased. While the development of El Niño, or even La Niña,
cannot be ruled out during the next few months, ENSO-neutral is now favored through the Northern
Hemisphere winter 2012-13 (see CPC/IRI consensus forecast).
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
6 December 2012
ENSO Alert System Status: Not Active
Synopsis: ENSO-neutral is favored for Northern Hemisphere winter 2012-13 and into spring 2013.
During November 2012, the Pacific Ocean reflected ENSO-neutral conditions. Equatorial sea surface temperatures (SST) anomalies were slightly positive across all of the tropical Pacific Ocean except for the far eastern portion (Fig. 1), as also indicated in the Niño indices (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) was also slightly above average (Fig. 3), with largest amplitude in the east-central part of the basin (Fig. 4). Despite the subsurface and surface Pacific Ocean being slightly warmer than average, the tropical atmosphere remained in an ENSO-neutral state. Upper-level and lower-level zonal winds were near average, and convection was slightly suppressed over the eastern and central tropical Pacific (Fig. 5). Thus, both the atmosphere and ocean indicated ENSO-neutral conditions.
Relative to last month, the SST model predictions increasingly favor ENSO-neutral, with many remaining just slightly above average in the Niño-3.4 region through the Northern Hemisphere winter 2012-13 and into spring 2013 (Fig. 6). While the tropical atmosphere and especially the ocean suggested borderline ENSO-neutral/ weak El Niño conditions at times from July to September, these signs have now largely dissipated. Therefore, it is considered unlikely that a fully coupled El Niño will develop during the next several months. ENSO-neutral is now favored through the Northern Hemisphere winter 2012-13 and into spring 2013 (see CPC/IRI consensus forecast).
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
10 January 2013
ENSO Alert System Status: Not Active
Synopsis: ENSO-neutral is favored through Northern Hemisphere spring 2013.
ENSO-neutral conditions continued during December 2012. Equatorial sea surface temperature (SST) anomalies were positive in the western Pacific, near zero in the central Pacific, and slightly negative in much of the eastern Pacific (Fig 1). This SST anomaly pattern is also reflected in the Niño indices (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) in the equatorial Pacific became slightly below average (Fig. 3), with positive sub-surface temperature anomalies west of 165W and stronger negative anomalies in the east-central and eastern Pacific (Fig. 4). Upper- and lower-level zonal winds were near average across the tropical Pacific, and the Southern Oscillation Index was slightly negative. Also, convection was suppressed over the central tropical Pacific and enhanced over western Indonesia (Fig. 5). Collectively, these oceanic and atmospheric features indicate ENSO-neutral conditions.
Model predictions favor near-average SST in the Niño-3.4 region from the Northern Hemisphere winter 2012-13 into summer 2013 (Fig. 6). Because predictions through the April-June season are known to be less skillful, the forecasts for the summer carry limited confidence at this time. Thus, it is considered unlikely that an El Niño or La Niña will develop during the next several months, and ENSO-neutral is favored through Northern Hemisphere spring 2013 (see CPC/IRI consensus forecast).
EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
7 February 2013
ENSO Alert System Status: Not Active
Synopsis: ENSO-neutral is favored through Northern Hemisphere spring 2013.
During January 2013, ENSO-neutral continued, although below-average sea surface temperatures (SST) prevailed across the eastern half of the equatorial Pacific (Fig. 1). While remaining below average, a high degree of variability in the weekly Niño 3 and 3.4 indices was apparent during the month (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) was also below-average (Fig. 3), largely reflecting negative subsurface temperature anomalies in the eastern Pacific. At the same time, positive anomalies increased and expanded eastward to the central Pacific by late January (Fig. 4). The variability in both the ocean and atmosphere was enhanced during January, at least partially due to a strong Madden-Julian Oscillation (MJO). Consequently, the location of the MJO was reflected in the monthly averages of wind and convection. Anomalous upper-level winds were westerly over the eastern half of the equatorial Pacific, while low-level winds were near average. Relative to December 2012, the region of enhanced convection shifted eastward and became more prominent over Indonesia and the western equatorial Pacific (Fig. 5). Despite these transient features contributing to cool conditions, the collective atmospheric and oceanic system reflects ENSO-neutral.
The vast majority of models predict near-average SST (between -0.5°C and +0.5°C) in the Niño-3.4 region through the late Northern Hemisphere summer (Fig. 6). However, because model skill is generally low during April-June, there is less confidence in the forecast beyond the spring. Thus, ENSO-neutral is favored through Northern Hemisphere spring 2013 (see CPC/IRI consensus forecast).
thanks in advance busterkelleyQuote:
Originally Posted by Buster Highmen
the snow piled up in the pnw.
bF
I'm guessing your forecast for this season's total snow is right on, but as the saying goes.;;Lies, damn lies, and statistics....Seems like Steamboat and Vail tallies are off by almost 100".
Mediocre season as far as pow days but I've seen much worse overall conditions. Ghee still has a 48-100" base off of only 360"ytd, which is actually a minor miracle in itself. I can think of three or four drought winters where a 360" season meant a late, rocky start and then a rotting snowpack by April, neither of which happened this year. Still, other than the really quick start to the season, not much else has been very memorable. One excellent 50" week in late January was the only "epic" so far. 25 more days left for the ghee to get over the 400" hump.
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issu
ed by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
9 May 2013
ENSO Alert System
Status: No
t Active
Synopsis:
ENSO
-
neutral is favored into the late Northern Hemisphere summer 2013.
During April 2013,
ENSO
-
neutral continued
, with near
-
average sea surface temperatures (SSTs)
observed across most of the equatorial Pacific Ocean, and below average
SSTs confined to the far eastern
equatorial Pacific
(Fig. 1).
The Niño indices were near zero throughout the month, except for the
Niño1+2 region which was
between
-
1.2
°C and
-
0.5°C
(Fig. 2).
The oceanic heat content
(average
temperature in the upper 300
m of
the
ocean)
remained near average during April
(Fig. 3), reflecting near
-
average subsurface temperatures
at depth across most of the central and eastern equatorial Pacific
(Fig. 4).
The tropical low
-
level easterly winds remained slightly enhanced over
the western half of the Pacific
basin, and anomalous upper
-
level westerly winds prevailed across much of the equatorial Pacific
.
Tropical convection was enhanced over Indonesia and the western Pacific and suppressed over the central
Pacific
(Fig. 5).
Coll
ectively, these conditions indicate the continuation of ENSO
-
neutral
.
Most models forecast
Niñ
o
-
3.4 SSTs to remain ENSO
-
neutral
into the Northern Hemisphere
winter
(Fig. 6)
, with dynamical models tending to predict warmer conditions (
-
0.3°C to
0.4°C) th
an the
statistical models (
-
0.7°C to 0°C)
.
There is still low confidence in the forecasts for the latter half of the
year, partly because of the so
-
called “spring barrier,” which historically leads to lower model skill for
forecasts made between March and
May. Forecast confidence will increase over the next few months.
The current forecast indicates that
ENSO
-
neutral
will likely continue
into the second half of the Northern
Hemisphere summer
2013
(see
CPC/IRI consensus forecast
)
.
It's pretty clear I didn't ski enough last winter, because I'm already thinking of next winter.
Attachment 138985
http://www.liveweatherblogs.com/inde...122&Itemid=179
holding at 65% chance of El Nino for '14-15
http://www.cpc.ncep.noaa.gov/product.../ensodisc.html
next reassessment, sept 4
From ^^^
The lack of a coherent atmospheric El Niño pattern, and a return to near-average SSTs in the central Pacific, indicate ENSO-neutral.
...
A strong El Niño is not favored in any of the ensemble averages, and slightly more models call for a weak event rather than a moderate event.
...
The chance of El Niño has decreased to about 65% during the Northern Hemisphere fall and early winter...
And the PNW is in the middle of the colder/wetter portion of the Pacific Decadal Oscillation (PDO).
There was a similar SST dip in July-August 1982, and we know how that ended up...
Guys, it will dump this winter, as I just started a new mortgage company and I am working 24/7 with little time to ski. I will have to be happy with the occasional dawn patrol at Swami's. Your welcome.
The Niño is favorably not good for Jackson Hole, so I want a weak Niño. However, we love La Niña here. She hits hard & often. Give us a weak El Niño this year & a strong La Niña the following year.
Saying that, you never know what will happen, just enjoy the winter. I just go by my history on my twelve going on thirteen winters out in the Rockies. First seven in AltaBird, last five going on six in Jackson.
As long as we don't have the 13-14 Tahoe winter.
Yeah. Fuck that. We need some goddamn water here. I'd take an average winter in the Central/Northern Sierra at this point.
See Klaus Wolter's thoughts below (underlining added for emphasis for the TL;DR crowd).
Quote:
Discussion and comparison of recent conditions with historic ENSO-neutral conditions
In the context of ENSO-neutral conditions from August-September 2013 through last boreal winter, this section features a comparison figure with persistent ENSO-neutral conditions for at least six bimonthly MEI values and ending in close proximity to the ranking of January-February 2014 MEI. Longer-lived neutral conditions (such as 1959-61) could only enter once into this comparison figure.
The updated (July-August) MEI has increased slightly to +0.86. Its current ranking has moved up to the 12th highest value for this time of year, in weak-to-moderate El Niño territory. The long anticipated emergence of El Niño conditions in 2014 is still under way, despite the lack of signal in Niño 3.4 (see below), leading to the next question of how big it will get. Of the 12 nearest-ranked July-August values, eight had come up by at least nine ranks over the previous four months (2014 has come by 19 ranks). In turn, six of these eight cases (1957, '86, '91, '02, '06, and '09) kept El Niño conditions going into the next calendar year, while the 1951 event ended prematurely by November, and 2004 struggled through the remainder of 2004. Three of these events unambiguously reached strong levels for several months: 1957-58, 1986-87, and 1991-92. So, a strong event is still possible (perhaps better than 1 in 3 odds), but is not the most likely outcome, while a crash before the end of 2014 appears to have about 1 in 4 odds.
Positive SST anomalies cover much of the central and eastern equatorial Pacific, as seen in the latest weekly SST map. Compared to last month, weak negative anomalies near 120W have disappeared, as have most of the negative SSt anomalies near 20S and off the South American coast, but the positive SST anomalies have not gained much ground in return.
For an alternate interpretation of the current situation, I recommend reading the NOAA ENSO Advisory which represents the official and most recent Climate Prediction Center opinion on this subject. In its latest update (September 4th, 2014), ENSO-neutral conditions were diagnosed, but were expected to transition to El Niño by the fall, at odds of 60%-65%. Differences in opinion are due to their requirement that El Niño conditions persist for a long period before acknowledging an event, and the fact that Niño 3.4 SST still has not crossed over their +0.5C anomaly threshold.
There are a number of ENSO indices that are kept up-to-date on the web. Several of these are tracked at the NCEP website that is usually updated around the same time as the MEI, in time for this go-around. In 2013, Niño regions 3 and 3.4 rose from close to -0.5C in January to within +/-0.2C in March and April of that year. While Niño 3 dropped back to -0.5C and even lower from May through August, Niño 3.4 remained less negative (around -0.3C) through this period. During September through December, both indices hovered close to or just under 0C. In early 2014, both indices dropped to around -0.5C for both indices, followed by a steady warm-up from March through June, reaching +0.9C for Niño 3, and just shy of +0.5C for Niño 3.4. In July 2014, both indices dropped by more than 0.2C, still above +0.5C for Niño 3, but only +0.2C for Niño 3.4. This continued during the month of August.
For extended Tahiti-Darwin SOI data back to 1876, and timely monthly updates, check the Australian Bureau of Meteorology website. This index has often been out of sync with other ENSO indices in the last decade, including a jump to +10 (+1 sigma) in April 2010 that was ahead of any other ENSO index in announcing La Niña conditions. In 2013, the SOI varied from slightly negative values early in the year (-4 in February) all the way to +14 in June and back down to -2 in October. It rose back up to +9 in November, consistent with potentially re-emerging La Niña conditions. However, the December value dropped right back to +1, only to be followed by a jump to +12 in January 2014, and back to slightly negative values (-1) in February. This was followed by a further drop to -13 in March 2014, its lowest March value since 1998(!). However, the April and May values went right back up to positive (La Niña) territory. In June and July 2014, it went back to (mild) negative values, only to drop further into El Niño-worthy values around -11 in August. The SOI remains the noisiest ENSO index that I can think of.
An even longer Tahiti-Darwin SOI (back to 1866) is maintained at the Climate Research Unit of the University of East Anglia website, however with less frequent updates (currently through January 2014). Extended SST-based ENSO data can be found at the University of Washington-JISAO website, which is now more than three years behind in its update (through January 2011).
Stay tuned for the next update by October 12th (or earlier) to see where the MEI will be heading next. El Niño came and went during the summer of 2012, not unlike 1953. I do not believe that this year's version will be quite as short-lived, not least because the PDO has remained positive through at least July in 2014, while it was quite negative back in 2012. The odds for a strong event have recovered slightly, while a moderate event is still the most likely outcome for now.
Cliff Mass is saying El Nino is building. Coupled with the Blob that's been off the BC coast, the forecast is increasingly ominous for the PNW and increasingly sweet for the SW.
http://cliffmass.blogspot.com/2014/0...ter-ahead.html
Also:
Temperature:
http://www.cpc.ncep.noaa.gov/product...off04_temp.gif
and
Precip:
http://www.cpc.ncep.noaa.gov/product...off04_prcp.gif
I saw this. Not good...
Quote:
Originally Posted by Buster Highmen
Everybody loves dice rolling!
I calculated storm tracks following McAfee and Russell 2008 (GRL) and differenced the ENSO positive and negative phases. Greener means more storminess, browner means less. Flip 'em for La Niña (and see why the PNDub loves her so much!) Donut matta for the Sierra! If anything, it is less favorable to have El Niño conditions. More specifically, the phasing of many other factors drives seasonal precipitation in the southcentral midlatitudes of the West Coast. The PNA shows up nicely as well in the geopotential height fields.
http://i262.photobucket.com/albums/i...s7be397c7.jpeg
A station-based approach (below, from the Western Regional Climate Center) is totally consistent and derived independently. Bear in mind that the relationship of Reno precip to western Sierra precip has a correlation coefficient of 0.8 over 91 years (it is just about 1/10 the magnitude), so this figure is valid for the greater region.
https://scontent-b-ord.xx.fbcdn.net/...c9&oe=54CC77DA
Burn more skis!
Edit to update ENSO-ST
Yup, looks live Valdez is going to get pounded....again!
-BOV
Cliff Mass says the blob is disappating:
http://cliffmass.blogspot.com/2014/1...s-meeting.html
despite the 6-10 above average temps of October.
These guys are claiming El Nino is now official.
http://www.southerncaliforniaweather...-now-official/
I think they're premature with that claim. http://www.cpc.ncep.noaa.gov/product...y/ensodisc.pdfQuote:
Originally Posted by RaisingArizona
CPC update from monday states that Neutral conditions continue. http://www.cpc.ncep.noaa.gov/product...-fcsts-web.pdf
Warm phase PDO development is interesting... http://www.esrl.noaa.gov/psd/map/cli...anom.anim.html
^^^ Only because of NOAA's time period requirement to make the declaration. See pages 19-20 of the second PDF.
See Klaus Wolter's comment:
It's only been the Nino 3.4 region that's been holding back the classification.Quote:
Differences in opinion are due to [CPC's] requirement that El Niño conditions persist for a long period before acknowledging an event, and the fact that Niño 3.4 SST still has not crossed over their +0.5C anomaly threshold.
That's an abuse of the term "Pacific Decadal Oscillation" which specifies a 40-50 year weather periodicity in which we are heading into the colder wetter phases.Quote:
Originally Posted by kai_ski
The phenomenon to which you refer has been called the "blob". And it's disappating: http://cliffmass.blogspot.com/2014/1...s-meeting.html
NOAA is always sadly behind the curve.
The link Kai posted said nothing about the PDO (which begs the question why he mentioned it out of context), so you're responding to a windmill. :biggrin:Quote:
Originally Posted by Buster Highmen
Nothing except he mentions "PDO", so yeah.Quote:
Originally Posted by LightRanger
I don't think it is. Even during persistent cold or warm phases, you can get spikes on the other end of the spectrum. Take a look at a time series of the PDO index.Quote:
Originally Posted by Buster Highmen
Attachment 159944
Attachment 159945
In my understanding, the PDO is a term that refers to decades long temperature and precip oscillations detected by tree ring and ice core samples. It's not a perfect sine wave. The noise or anomalies in the PDO are not what makes it notable or nameable.Quote:
Originally Posted by kai_ski
If anything, as mentioned tens of times, we're heading into the colder, wetter phase of the PDO.
To refer to a "Warm phase PDO development" would not be referring to the phase of the PDO into which we are currently going and is inconsistent with the convention.
Cliff Mass has referred to what you're referring to as "the blob". See the link.
Also: (from http://en.wikipedia.org/wiki/Pacific...al_oscillation).
MacDonald and Case[24] reconstructed the PDO back to 993 using tree rings from California and Alberta. The index shows a 50-70 year periodicity but this is a strong mode of variability only after 1800, a persistent negative phase occurred during medieval times (993-1300) which is consistent with la nina conditions reconstructed in the tropical Pacific[25] and multi-century droughts in the South-West United States.[26]
Several regime shifts are apparent both in the reconstructions and instrumental data, during the 20th century regime shifts associated with concurrent changes in SST, SLP, land precipitation and ocean cloud cover occurred in 1924/1925,1945/1946 and 1976/1977:[27]
1750: PDO displays an unusually strong oscillation.[4]
1924/1925: PDO changed to a "warm" phase.[27]
1945/1946: The PDO changed to a "cool" phase, the pattern of this regime shift is similar to the 1970s episode with maximum amplitude in the subarctic and subtropical front but with a greater signature near the Japan while the 1970s shift was stronger near the American west coast.[27][28]
1976/1977: PDO changed to a "warm" phase.[29]
1988/1989:A weakening of the Aleutian low with associated SST changes was observed,[30] in contrast to others regime shifts this change appears to be related to concurrent extratropical oscillation in the North Pacific and North Atlantic rather than tropical processes.[31]
1997/1998: Several changes in Sea surface temperature and marine ecosystem occurred in the North Pacific after 1997/1998, in contrast to prevailing anomalies observed after the 1970s shift. The SST declined along the United States west coast and substantial changes in the populations of salmon, anchovy and sardine were observed as the PDO changed back to a cool "anchovy" phase .[32] However the spatial pattern of the SST change was different with a meridional SST seesaw in the central and western Pacific that resembled a strong shift in the North Pacific Gyre Oscillation rather than the PDO structure. This pattern dominated much of the North Pacific SST variability after 1989.[33]
So in the literature at least, a "phase" refers to a temperature/precip pattern in the large, not in any aberations from the norm of the phase.
Thanks, Sancho.