La Nina SOI number continue to Drop

[VAwxman]

I said 2011-12 would be weak Niño way back before this winter began... still looking like it. In the longer term it may become west-based.

Just like we weren't supposed to get a la nina this past year?

[okie333]

Just like we weren't supposed to get a la nina this past year?

Take a look at my map from July (google okie333 to see it; it should be the top result). Other than Maine it's a very good match with the pattern so far. I got the USA pattern right, I just underestimated a detail that has had little effect for most of the winter (it has still acted like a neutral-ish pattern for the most part in the USA).

[MN Transplant]

I'll say this is a simply matter of not having enough data.

Since 1950, there have been only 6 Strong La Nina's. That's one every 8.3 years.

Since 1950, there have been only 6 Strong El NIno's. That's one every 8.3 year too.

Based on these numbers, we should expect a Strong El Nino to follow a Strong La Nina once every 69 years. 1/69. We are 0/60, which really proves nothing in this regard.

The odds of having a Strong El Nino are always very low. Climo says the event is unlikely, but that doesn't mean it can't happen. We have to consider it as a possibility, maybe even an above average one.

Just curious, what do you consider 1904 to 1905?

[uncle W]

I've been looking at some summer analog years with a fading la nina...The years started La nina and ended El nino or a weak positive...

1951

1957

1963

1968

1972

1976

1989

1965

2009

I hope next year isn't a neutral year...Neutral after nina is putrid...

1985

1989

1996

2001

[A-L-E-X]

Unc, you read my mind about neutral after la nina-- two winters that come to mind are 1989-90 and 2001-02

[wxmx]

El Niño talk is quite strong in this thread, but I mostly disagree with the calls of a likely demise of La Niña. I saw the current weakening of the La Niña back in early January when a rather strong MJO wave was forecasted to cross the dateline, as it did, indeed, but there have been no signs of a stronger atmospheric kickoff that I would expect to get the El Niño train moving. By that I mean WWBs/KWs crossing the Pacific which have been non-existent to date, at least in a trackable fashion.

We have many factors against an El Niño surfacing, including the PDO, the SOI, statistics and forecasted easterly surges. Other than the current weakening trend (surface and subsurface) and the solar factor, which I think is poorly understood, with little explanation of the mechanism involved and with an anemic ramp up so far, odds are against an El Niño, moreso a strong one. A La Niña state is more stable than a Niño one, with a moderate/strong Niña very likely to be followed by another cold ENSO event.

OHC has been steadily increasing in all ENSO areas, and if this spring starts to feature WWBs/KWs we might see a warm event, but at least in the short term, things are against it.

My call is for a weak La Niña spring with a gradual cooling phase during the summer/autumn for a second Niña winter in a row.

[nzucker]

My call is for a weak La Niña spring with a gradual cooling phase during the summer/autumn for a second Niña winter in a row.

I think many are wishcasting an El Niño regime because it portends better for the mid-Atlantic winter, but the reality is that a transition from moderate/strong El Niño to strong La Niña as we saw generally implies more than one cold ENSO year....recent examples are 1973-76, 1998-2001, and 2007-2009. I don't think we can really beat the analogs and dynamical models at this range, so I'm skeptical of anyone favoring a warm development over the summer. Short-term trends in Region 1.2 SSTs have had little predictive power in the past over the next winter's ENSO state; both March 1999 and March 2008 saw significant warm pools in the eastern regions but then there was a resurgence of La Niña the next winter.

-PDO also implies a cold ENSO state absent other forcings. As Chuck has said, the Earth is in a strong -AAM/-PDO regime whose momentum will be hard to break. We had quite a string of La Niña winters to start the last -PDO phase with 48-49, 49-50, 50-51, 54-55, 55-56, 56-57. I wouldn't be surprised to see another run of this nature.

Agree with all your thoughts!

[rainstorm]

I think many are wishcasting an El Niño regime because it portends better for the mid-Atlantic winter, but the reality is that a transition from moderate/strong El Niño to strong La Niña as we saw generally implies more than one cold ENSO year....recent examples are 1973-76, 1998-2001, and 2007-2009. I don't think we can really beat the analogs and dynamical models at this range, so I'm skeptical of anyone favoring a warm development over the summer. Short-term trends in Region 1.2 SSTs have had little predictive power in the past over the next winter's ENSO state; both March 1999 and March 2008 saw significant warm pools in the eastern regions but then there was a resurgence of La Niña the next winter.

-PDO also implies a cold ENSO state absent other forcings. As Chuck has said, the Earth is in a strong -AAM/-PDO regime whose momentum will be hard to break. We had quite a string of La Niña winters to start the last -PDO phase with 48-49, 49-50, 50-51, 54-55, 55-56, 56-57. I wouldn't be surprised to see another run of this nature.

Agree with all your thoughts!

i was going to say the same thing. i think alot of the el nino talk is winter wishcasting. i personally much prefer an active cane season so i certainly hope and pray there is no el nino and wxmx is right.

[A-L-E-X]

I think many are wishcasting an El Niño regime because it portends better for the mid-Atlantic winter, but the reality is that a transition from moderate/strong El Niño to strong La Niña as we saw generally implies more than one cold ENSO year....recent examples are 1973-76, 1998-2001, and 2007-2009. I don't think we can really beat the analogs and dynamical models at this range, so I'm skeptical of anyone favoring a warm development over the summer. Short-term trends in Region 1.2 SSTs have had little predictive power in the past over the next winter's ENSO state; both March 1999 and March 2008 saw significant warm pools in the eastern regions but then there was a resurgence of La Niña the next winter.

-PDO also implies a cold ENSO state absent other forcings. As Chuck has said, the Earth is in a strong -AAM/-PDO regime whose momentum will be hard to break. We had quite a string of La Niña winters to start the last -PDO phase with 48-49, 49-50, 50-51, 54-55, 55-56, 56-57. I wouldn't be surprised to see another run of this nature.

Agree with all your thoughts!

I agree with you that I think there will be a weak la nina next winter, but I disagree in that I think the nao will be more positive..... I believe that we've broken the back of the two year neg AO/NAO extreme pattern and, since the effect of ENSO is cumulative in a multiyear pattern, I think the chances of a strong NAO block are much less than they were this winter, even though La Nina was strong this winter-- it came after a strong El Nino from the year before; as others have said, this introduced a "lag" effect, which is well known in producing big winters in our area in La Ninas that come after moderate or strong El Ninos. You could see this in how strongly our December and January pattern resembled the blocking we had last winter.

I don't think you should be very enthusiastic about La Nina for next winter, because most of our snow totals will be cut more than one half if not one third to one quarter, if a positive NAO surfaces with the La Nina, even if it's weak. Paradoxically, the other scenario I had in mind is even worse-- if we have a neutral ENSO next winter-- which would bring some dreaded analogs into focus. I believe our only hope of having a sustained neg NAO next winter would be with a weak-mod el nino-- if that doesnt materialize, then we will have a pos NAO.

[SnowGoose69]

I've been looking at some summer analog years with a fading la nina...The years started La nina and ended El nino or a weak positive...

1951

1957

1963

1968

1972

1976

1989

1965

2009

I hope next year isn't a neutral year...Neutral after nina is putrid...

1985

1989

1996

2001

Neutral winters seem to have a tendency to be poor for snow and cold for whatever reason in most areas in the East and northern Plains, if I recall correctly there is often an enhanced region of high pressure centered across Nevada, Idaho, and Utah during those winters which usually causes Pacific air to flood the country...we saw that in 01-02.

[JBG]

I wouldn't be surprised to see the La Niña make another run this summer...a lot of the years that went from strong Niño-->strong Niña stayed in the -ENSO category for a while...definitely the mid 70s examples and years after 1998 are good examples. Of course the recent CME/solar burst may have increased the chances that we develop an El Niño, but I'm still not on that train yet.

The early to mid-1950's are a perhaps more classic and better example.

[nzucker]

The early to mid-1950's are a perhaps more classic and better example.

We didn't have a switch from a strong Niño to a strong Niña though.

51-52 was a weak Niño and then the train of Niña winters got going. Most of those winters were putrid in the East except 55-56. It was a very poor stretch for NYC in terms of snowfall.

[JBG]

Unc, you read my mind about neutral after la nina-- two winters that come to mind are 1989-90 and 2001-02

Wasn't 1960-1 neutral after La Niña?

[JBG]

El Niño talk is quite strong in this thread, but I mostly disagree with the calls of a likely demise of La Niña. I saw the current weakening of the La Niña back in early January when a rather strong MJO wave was forecasted to cross the dateline, as it did, indeed, but there have been no signs of a stronger atmospheric kickoff that I would expect to get the El Niño train moving. By that I mean WWBs/KWs crossing the Pacific which have been non-existent to date, at least in a trackable fashion.********My call is for a weak La Niña spring with a gradual cooling phase during the summer/autumn for a second Niña winter in a row.

I tend to agree. Isn't this time of year also remarkably difficult to sort out as to ENSO trends?

[nzucker]

Wasn't 1960-1 neutral after La Niña?

59-60 and 60-61 were both neutral-neg/weak Niña winters.

[JBG]

....but the reality is that a transition from moderate/strong El Niño to strong La Niña as we saw generally implies more than one cold ENSO year....recent examples are 1973-76, 1998-2001, and 2007-2009. I don't think we can really beat the analogs and dynamical models at this range, so I'm skeptical of anyone favoring a warm development over the summer. Short-term trends in Region 1.2 SSTs have had little predictive power in the past over the next winter's ENSO state; both March 1999 and March 2008 saw significant warm pools in the eastern regions but then there was a resurgence of La Niña the next winter.

-PDO also implies a cold ENSO state absent other forcings. As Chuck has said, the Earth is in a strong -AAM/-PDO regime whose momentum will be hard to break. We had quite a string of La Niña winters to start the last -PDO phase with 48-49, 49-50, 50-51, 54-55, 55-56, 56-57. I wouldn't be surprised to see another run of this nature.

You left 1953-4 out of the "Niña train" of 1950's winters.

I think many are wishcasting an El Niño regime because it portends better for the mid-Atlantic winter,

i was going to say the same thing. i think alot of the el nino talk is winter wishcasting. i personally much prefer an active cane season so i certainly hope and pray there is no el nino and wxmx is right.

I echo that. However, this past winter, 1916-17 and the early 1800's winters were rather severe winters that feature strong Niñas. I think that with blocking, a strong Niña can be as productive of cold and snow as a Niño. We have not had real torching this winter, and only a few "cutters". Even 1977-78, the gold standard of weak Niño winters, had at least two nasty cutters.

[A-L-E-X]

We didn't have a switch from a strong Niño to a strong Niña though.

51-52 was a weak Niño and then the train of Niña winters got going. Most of those winters were putrid in the East except 55-56. It was a very poor stretch for NYC in terms of snowfall.

This is what I think will happen next winter if we have a la nina. Oh well, I guess we'll see. On the plus side, if this happens, I think JBG will get his back to back hot summers and a very active tropical season also.

[JBG]

This is what I think will happen next winter if we have a la nina. Oh well, I guess we'll see. On the plus side, if this happens, I think JBG will get his back to back hot summers and a very active tropical season also.

Didn't we have back-to-back severe winters with moderate-to-strong Niñas during WW I and Jefferson's Presidency? And that question is only 1/4 facetious.

Isn't NAO more important than ENSO in fixing the severity of our winters?

[A-L-E-X]

Didn't we have back-to-back severe winters with moderate-to-strong Niñas during WW I and Jefferson's Presidency? And that question is only 1/4 facetious.

Isn't NAO more important than ENSO in fixing the severity of our winters?

Yes, but ENSO does influence NAO, and the effect is cumulative. I think part of the reason we were able to sustain a neg nao earlier in the winter is because the previous winter was a strong el nino; we have a pretty good track record in winters in which we're switching from el nino to la nina. We'll see about next winter, but 1917-18 is going to be hard to repeat. Maybe if the sun stays "quiet" we can have sustained blocking again.

[SnowGoose69]

Yes, but ENSO does influence NAO, and the effect is cumulative. I think part of the reason we were able to sustain a neg nao earlier in the winter is because the previous winter was a strong el nino; we have a pretty good track record in winters in which we're switching from el nino to la nina. We'll see about next winter, but 1917-18 is going to be hard to repeat. Maybe if the sun stays "quiet" we can have sustained blocking again.

I would agree we could be in trouble if we have another La Nina next winter, we've seen how brutal the pattern has been the last few weeks and this is what we all thought would probably occur at least for all of January and the beginning of February going into this winter if not for the entire winter up until the last 2 weeks of February for those who were not even going for a cold December. I don't think the Nina would be strong but there would likely be a tendency towards a +NAO for sure. As of now most of the ENSO models still say no real pronounced Nina but many have cooled from the last time I looked at them 6 weeks back...I thik only 2 were below -0.5 back then, now a few more are.

[SnowGoose69]

Didn't we have back-to-back severe winters with moderate-to-strong Niñas during WW I and Jefferson's Presidency? And that question is only 1/4 facetious.

Isn't NAO more important than ENSO in fixing the severity of our winters?

The AO, PNA, and EPO are alot more important, examples of that are 93-94, 96-97, and 02-03....93-94 had a very positive NAO but a -EPO and -AO...96-97 had a -NAO but a generally +AO after December with the exception of the very first few days of January, the EPO I think was also generally neutral to positive, hence the Pacific basically overwhelmed the pattern....02-03 the NAO was positive for most of the winter despite the fact most people probably would believe otherwise, the EPO though was raging negative with I think the January value only being outdone by January 94 and January 78...the AO was negative through most of the winter though it went positive mid-February or so and the PNA was as positive as ever, only the winter of 76-77 I think had a higher averaging PNA. ...the Atlantic was basically awesome for the 96-97 winter yet it did squat for the eastern U.S...it was equally as lousy for 02-03 alot of the time yet the Pacific made up for it.

[A-L-E-X]

I would agree we could be in trouble if we have another La Nina next winter, we've seen how brutal the pattern has been the last few weeks and this is what we all thought would probably occur at least for all of January and the beginning of February going into this winter if not for the entire winter up until the last 2 weeks of February for those who were not even going for a cold December. I don't think the Nina would be strong but there would likely be a tendency towards a +NAO for sure. As of now most of the ENSO models still say no real pronounced Nina but many have cooled from the last time I looked at them 6 weeks back...I thik only 2 were below -0.5 back then, now a few more are.

We got so lucky this winter SG; yes most of the LR forecasts were off, but when you analyze it, it was just a matter of timing. It looks like the la nina has broken the back of the two year AO/NAO block we were in, and I think we need an ENSO turnaround to bring it back in a sustained form. I wonder how many times we've had incredible blocking like that for three winters in a row? The late 70s come to mind, but two of those winters were weak el ninos. The 02-03/03-04/04-05 stretch was primarily el nino driven also.

[A-L-E-X]

The AO, PNA, and EPO are alot more important, examples of that are 93-94, 96-97, and 02-03....93-94 had a very positive NAO but a -EPO and -AO...96-97 had a -NAO but a generally +AO after December with the exception of the very first few days of January, the EPO I think was also generally neutral to positive, hence the Pacific basically overwhelmed the pattern....02-03 the NAO was positive for most of the winter despite the fact most people probably would believe otherwise, the EPO though was raging negative with I think the January value only being outdone by January 94 and January 78...the AO was negative through most of the winter though it went positive mid-February or so and the PNA was as positive as ever, only the winter of 76-77 I think had a higher averaging PNA. ...the Atlantic was basically awesome for the 96-97 winter yet it did squat for the eastern U.S...it was equally as lousy for 02-03 alot of the time yet the Pacific made up for it.

Yup 93-94 and 02-03 were the poster children for how the Pacific can overrule the Atlantic.

[tacoman25]

I would agree we could be in trouble if we have another La Nina next winter, we've seen how brutal the pattern has been the last few weeks and this is what we all thought would probably occur at least for all of January and the beginning of February going into this winter if not for the entire winter up until the last 2 weeks of February for those who were not even going for a cold December. I don't think the Nina would be strong but there would likely be a tendency towards a +NAO for sure. As of now most of the ENSO models still say no real pronounced Nina but many have cooled from the last time I looked at them 6 weeks back...I thik only 2 were below -0.5 back then, now a few more are.

The NAO hasn't really been that positive overall the past couple months, though, has it?

[tacoman25]

Yup 93-94 and 02-03 were the poster children for how the Pacific can overrule the Atlantic.

Yup, but unlikely we see a repeat anytime soon in this -PDO phase.

[Isotherm]

I would agree we could be in trouble if we have another La Nina next winter, we've seen how brutal the pattern has been the last few weeks and this is what we all thought would probably occur at least for all of January and the beginning of February going into this winter if not for the entire winter up until the last 2 weeks of February for those who were not even going for a cold December. I don't think the Nina would be strong but there would likely be a tendency towards a +NAO for sure. As of now most of the ENSO models still say no real pronounced Nina but many have cooled from the last time I looked at them 6 weeks back...I thik only 2 were below -0.5 back then, now a few more are.

Can't say I agree here. If we have a weaker La Nina event next winter, the prospects of a -NAO increase quite a bit. My theory regarding the solar-NAO connection worked out well this year, so if we remain on the low side w/ geomagnetic activity, another highly blocked winter is possible. If we see a rapid increase in solar activity, paritcularly the aa index, then +NAO/AO probability rises (assuming another La Nina). With that being said, there are no guarantees either way, since a ramp-up in sunspot activity could induce a SSW event(s), but whether they propagate downward and impact the NAO modality is anyone's guess. I'd personally feel much more comfortable w/ -NAO prospects in a low solar env rather than a high one.

This winter we're finally seeing the effects of the power house nina on the global regime. Also, even w/ the strong nina, we're not seeing a raging positive NAO (which we'd probably see if not for the low geomag environment).

[Isotherm]

Yup, but unlikely we see a repeat anytime soon in this -PDO phase.

Chances definitely far lower now, but we can get a few stray winters with a pretty positive +PDO within the negative decadal phase (1960-61 is a good example -- great pacific, ok atlantic, excellent winter).

[nzucker]

Didn't we have back-to-back severe winters with moderate-to-strong Niñas during WW I and Jefferson's Presidency? And that question is only 1/4 facetious.

Isn't NAO more important than ENSO in fixing the severity of our winters?

1916-17 was a moderate La Niña with a very cold regime; 1917-1918 was a weak Niña with brutal cold.

We got so lucky this winter SG; yes most of the LR forecasts were off, but when you analyze it, it was just a matter of timing. It looks like the la nina has broken the back of the two year AO/NAO block we were in, and I think we need an ENSO turnaround to bring it back in a sustained form. I wonder how many times we've had incredible blocking like that for three winters in a row? The late 70s come to mind, but two of those winters were weak el ninos. The 02-03/03-04/04-05 stretch was primarily el nino driven also.

I think that many long-range forecasters envisioned the turnaround in pattern, however...I said that December would be the coldest month and February the mildest, with the trough shifting into the west and the AO/NAO becoming more positive. I didn't think the blocking would hold out as long in January, that was unprecedented for a strong La Niña and perhaps related to the low geomagnetic flux that Isotherm had highlighted in his forecast. We're definitely seeing the 1989/1955 pattern where the cold anomalies moved into the west for February after the winter had started colder east. March will be a wild card, but all signs are that the back of the blocking has been broken...the vortex over Baffin Island and the Canadian Archipelago doesn't want to disappear.

Can't say I agree here. If we have a weaker La Nina event next winter, the prospects of a -NAO increase quite a bit.

We've seen some great -NAO blocks in weak La Niñas like 95-96 and 66-67, but of course these winters followed El Niño. There may be a lag effect in terms of stratosphere temperatures and developments of the polar vortex.

[wxmx]

Feb 2011 marks the 8th month with a SOI >16. The 1917-1918 12-month streak of a SOI >14 doesn't look that far fetched now.

[tacoman25]

Chances definitely far lower now, but we can get a few stray winters with a pretty positive +PDO within the negative decadal phase (1960-61 is a good example -- great pacific, ok atlantic, excellent winter).

Yeah, 1960-61 was one of the more +PDO winters from 1946-76, but still not as +PDO as 1993-94 or especially 2002-03.

I can pretty much guarantee that next winter will be -PDO, probably signficantly so (unless we see a mod/strong El Nino rise out of nowhere). Look at just about every other winter (aside from mod/strong Ninos) that followed a major La Nina in -PDO phase: 1950-51, 1951-52, 1956-57, 1971-72, 1974-75, 2008-09...