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2015 ENSO super thread


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Apparently CPC changed their methodology again and now we're no longer in an El Nino (yet)...  And actually, because JFM was <+0.5 and you need 5 consecutive tri-monthly means at or above 0.5, the soonest we can achieve El Nino now will be after the JJA reading comes in! (which won't be until early Sep). 

 

Just stating the facts here, I haven't read the paper yet so I haven't formed an opinion on the change.

 

http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

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Apparently CPC changed their methodology again and now we're no longer in an El Nino (yet)...  And actually, because JFM was <+0.5 and you need 5 consecutive tri-monthly means at or above 0.5, the soonest we can achieve El Nino now will be after the JJA reading comes in! (which won't be until early Sep). 

 

Just stating the facts here, I haven't read the paper yet so I haven't formed an opinion on the change.

 

http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

I noticed this today...Why the change...was 1979-80 an official el nino before the change???

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Today's 0Z Euro goes full steam ahead with the forecasted big SOI drop in recent days' runs for late month with some days of the last week of June likely at least rivaling the most negative SOI's of the year to date (-40's). By 6/20, there should already be a pretty solid -SOI. It may then rise back to less negative for a couple of days. However, once we get to 6/24 and especially beyond, look out below!

I wonder if this big SOI drop will lead to major changes in the US pattern by early July. Opinions?

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Today's 0Z Euro goes full steam ahead with the forecasted big SOI drop in recent days' runs for late month with some days of the last week of June likely at least rivaling the most negative SOI's of the year to date (-40's). By 6/20, there should already be a pretty solid -SOI. It may then rise back to less negative for a couple of days. However, once we get to 6/24 and especially beyond, look out below!

I wonder if this big SOI drop will lead to major changes in the US pattern by early July. Opinions?

 

I talked about this index last year and got some heavy criticism from some folks here about it. But it has been proving itself a very useful means to quantify the atmospheric response to ENSO and the Day 15 forecast is now jumping up to 2.3 standard deviations above average for the time of year. We are now observing an atmospheric response to El Nino stronger than last year. The only other years to best match the amount of eastern Pacific forcing during June is 1992, and 1997/1998 (dating back to 1950). I fully expect Nino like conditions to evolve across the lower 48 during July into August. 

https://twitter.com/WSI_Energy/status/611885922775363584

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I talked about this index last year and got some heavy criticism from some folks here about it. But it has been proving itself a very useful means to quantify the atmospheric response to ENSO and the Day 15 forecast is now jumping up to 2.3 standard deviations above average for the time of year. We are now observing an atmospheric response to El Nino stronger than last year. The only other years to best match the amount of eastern Pacific forcing during June is 1992, and 1997/1998 (dating back to 1950). I fully expect Nino like conditions to evolve across the lower 48 during July into August. 

https://twitter.com/WSI_Energy/status/611885922775363584

Cool East?

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Looking at the SOI outlook for June:

Per the latest model consensus with an emphasis on the Euro, there is still no indication that the SOI is headed back to the strongly -SOI's that dominated most of May at least through ~6/16. So, as of now the projection for June 1-16 is for at most a modestly negative SOI. This raises the chance that June overall won't be a strongly -SOI month. IF that were to occur, it would represent a significant + diversion of this June's SOI from the solidly to strongly -SOI consensus of June for the nine analogs that I've found that were either (oncoming) 2nd year strong/super or standalone oncoming superstrong Nino's:

1997: -24.3

1987: -17.9

1982: -17.2

1972: -10.9

1940: -17.2

1905: -27.7

1896: -27.0

1888: -14.4

1877: -7.0

By the way, the July #'s were similar: -9.0, -17.3, -17.9, -17.3, -14.3, -19.8, -19.1, -15.5, -9.5

Per the 0Z 6/22 Euro, there look to be more strongly -SOI days over the next few with a bottom ~6/25-6 in the high -30's to low -40's before a rise back to near the -15 to -10 range 6/30. Based on these projections, my first rough estimate for the June SOI as a whole is for -7 to -9, which would be quite a comeback into negative territory after having been +5 MTD as late as 6/15. Regarding how this June would compare to past either 2nd year Nino's that were strong to superstrong or standalone superstrong going back to 1877-8 (nine years in the sample..see list above), this would be in range but near the lowest magnitude of negative for June, which was -7.0 in 6/1877. The average for the sample of nine is -18. It will be interesting to see how July gets going. It looks to start pretty negative with perhaps -10's on 7/2.

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Per the 0Z 6/22 Euro, there look to be more strongly -SOI days over the next few with a bottom ~6/25-6 in the high -30's to low -40's before a rise back to near the -15 to -10 range 6/30. Based on these projections, my first rough estimate for the June SOI as a whole is for -7 to -9, which would be quite a comeback into negative territory after having been +5 MTD as late as 6/15. Regarding how this June would compare to past either 2nd year Nino's that were strong to superstrong or standalone superstrong going back to 1877-8 (nine years in the sample..see list above), this would be in range but near the lowest magnitude of negative for June, which was -7.0 in 6/1877. The average for the sample of nine is -18. It will be interesting to see how July gets going. It looks to start pretty negative with perhaps -10's on 7/2.

 

 The -SOI daily low peak for this drop was almost definitely today as tomorrow's should rise into the lower -40's and possibly up to the high -30's. It will mostly rise between now and 7/6, when it could be a small positive though it should still be negative come 6/30. (maybe near -15?)

 Kudos to the Euro model for doing well in forecasting the SOI all of this month.

 My current projection for June as a whole is for between -9 and -10, which represents quite an abrupt turnaround from the MTD of +5 as of 6/15. Also, compare this -9 to-10 to these strong El Nino June analogs:

 

 

1997: -24.3

1987: -17.9

1982: -17.2

1972: -10.9

1940: -17.2

1905: -27.7

1896: -27.0

1888: -14.4

1877:   -7.0

 

 So, it will end up similar to 1877 and 1972.

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Yep looks like this El Nino is the real deal for the first time since 2009-2010. The last few were phonies.

 

Have to respectfully disagree with this statement. While CPC's ONI didn't show the El Nino conditions that materialized last Spring through the Summer, there's no arguing we didn't see an atmospheric response. Just in brevity, we saw a cooler than average summer in the U.S. (eastern two thirds), a ton of West Pacific and East Pacific tropical cyclones, and a boring Atlantic hurricane season. Fits the criteria for a Summer El Nino (getting a bit more nerdy, atmospheric angular momentum was high and SOI was negative last summer).  Now I have to agree with you however where this Nino event is the real deal and could even rival 1997's amplitude at its highest point. 

 

In the end, I think us meteorologists need to reconsider our definition of El Nino. There are times when oceanic Kelvin wave activity can drive the Nino pattern (Nina to Modoki to Full Basin). While I get the idea for a 3-month aggregate to filter out the intraseasonal variability, knowing whether the atmosphere is an El Nino versus La Nina state on the time scale of 1 or 2 months makes all the difference in long-range forecasting.

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The -SOI daily low peak for this drop was almost definitely today as tomorrow's should rise into the lower -40's and possibly up to the high -30's. It will mostly rise between now and 7/6, when it could be a small positive though it should still be negative come 6/30. (maybe near -15?)

 Kudos to the Euro model for doing well in forecasting the SOI all of this month.

 My current projection for June as a whole is for between -9 and -10, which represents quite an abrupt turnaround from the MTD of +5 as of 6/15. Also, compare this -9 to-10 to these strong El Nino June analogs:

 

 

1997: -24.3

1987: -17.9

1982: -17.2

1972: -10.9

1940: -17.2

1905: -27.7

1896: -27.0

1888: -14.4

1877:   -7.0

 

 So, it will end up similar to 1877 and 1972.

June ended up at -10.30. The first half was at +5 while the second half was near -25. What a contrast! Although the month ended near 1972 levels, the last half, alone, was more like some of the stronger -SOI Junes.

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Still way too early, obviously, to make any solid predictions about winter, but I do wonder, since this El Nino event seems to be positioning more to the east, in a more traditional fashion, if that'll have any adverse impact in terms of cold and snow down the road. I know many have said basin-wide or west-based events are preferable when it's a stronger event.

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Per the 0Z Euro, volatility is ahead: SOI should drop back to near low -30's 7/2-3 before rapidly rising to the general vicinity of +20 by 7/6-7. Then it is predicted to fall back some but still be around +10 or maybe +teens 7/10-11. Based on this, 7/1-11 may end up averaging not far from 0...perhaps near -1.

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Still way too early, obviously, to make any solid predictions about winter, but I do wonder, since this El Nino event seems to be positioning more to the east, in a more traditional fashion, if that'll have any adverse impact in terms of cold and snow down the road. I know many have said basin-wide or west-based events are preferable when it's a stronger event.

 

East based now. Map below looks basin-wide to me.

 

 

 ssta.glob.DJF2016.1jun2015.gif

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Still way too early, obviously, to make any solid predictions about winter, but I do wonder, since this El Nino event seems to be positioning more to the east, in a more traditional fashion, if that'll have any adverse impact in terms of cold and snow down the road. I know many have said basin-wide or west-based events are preferable when it's a stronger event.

I'd hedge strongly towards a rather meek winter, with the greatest snowfall anomalies in the interior, save for a fluke KU.

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The latest CFSv2 ENSO forecast is indicating that the ENSO Region 1+2 anomaly will be at or above +1.00°C throughout meteorological winter (December-February). It is also indicating this region's anomaly should have peaked, will fall, and then again increase.

 

A secondary peak is actually not uncommon during strong or super El Niño events.The 1972-73, 1982-83, and 1997-98 events all had secondary peaks in this region. The 1997-98 event had a tertiary peak.

 

ENSO07102015.jpg

 

Since 1950, only three meteorological winters saw 2 or more months have Region 1+2 anomalies of +1.00°C or above: 1972-73, 1982-83, and 1997-98. The latter two featured all three months with such anomalies.

 

Given the modeling, it is very likely that August will have a Region 1+2 anomaly of at least +1.00°C. Since 1950, such anomalies have occurred in 1951, 1957, 1965, 1972, 1976, 1982, 1983, 1987, 1997, 1998, 2008, 2009, and 2014. However, only 3 of those 13 cases met the threshold being signaled on the CFSv2.

 

By October, ENSO Region 1+2 anomalies of +1.5°C or above, filtered out almost all of those cases, leaving only 1972, 1982, 1987, and 1997. Hence, by October, we should have a strong signal as to whether this current CFSv2 forecast has a reasonable chance of verifying.

 

In November, using the same anomaly threshold as October, only 1972, 1982, and 1997 remained.

 

Such anomalies during meteorological winter would have implications for North American temperature anomalies and possibly snowfall along the East Coast. Should the strong PDO+ persist, the PNA+ could also predominate (1982-83 and 1997-98) leading to another warmer than normal winter in the Pacific Northwest. All of that is still far out, but the scenario currently shown on the CFSv2 would typically favor warmth across much of North America.

 

In the more immediate future, one has typically seen El Niño events with Region 1+2 anomalies at or above +1.00°C produce cool anomalies in large parts of the East in August. Summer 2009 was an exception. Warmth has sometimes occurred in the Pacific Northwest and western half of the U.S.

 

In the end, it's still too soon to be sure about the upcoming winter. But if the CFSv2 is right, a cool autumn could yield to a warmer to much warmer than normal December across a wide swath of the U.S.

 

Given where things stand, one should be aware of this possible scenario, but not yet lock it in. Much can still change in Region 1+2.

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The latest CFSv2 ENSO forecast is indicating that the ENSO Region 1+2 anomaly will be at or above +1.00°C throughout meteorological winter (December-February). It is also indicating this region's anomaly should have peaked, will fall, and then again increase.

 

A secondary peak is actually not uncommon during strong or super El Niño events.The 1972-73, 1982-83, and 1997-98 events all had secondary peaks in this region. The 1997-98 event had a tertiary peak.

 

ENSO07102015.jpg

 

Since 1950, only three meteorological winters saw 2 or more months have Region 1+2 anomalies of +1.00°C or above: 1972-73, 1982-83, and 1997-98. The latter two featured all three months with such anomalies.

 

Given the modeling, it is very likely that August will have a Region 1+2 anomaly of at least +1.00°C. Since 1950, such anomalies have occurred in 1951, 1957, 1965, 1972, 1976, 1982, 1983, 1987, 1997, 1998, 2008, 2009, and 2014. However, only 3 of those 13 cases met the threshold being signaled on the CFSv2.

 

By October, ENSO Region 1+2 anomalies of +1.5°C or above, filtered out almost all of those cases, leaving only 1972, 1982, 1987, and 1997. Hence, by October, we should have a strong signal as to whether this current CFSv2 forecast has a reasonable chance of verifying.

 

In November, using the same anomaly threshold as October, only 1972, 1982, and 1997 remained.

 

Such anomalies during meteorological winter would have implications for North American temperature anomalies and possibly snowfall along the East Coast. Should the strong PDO+ persist, the PNA+ could also predominate (1982-83 and 1997-98) leading to another warmer than normal winter in the Pacific Northwest. All of that is still far out, but the scenario currently shown on the CFSv2 would typically favor warmth across much of North America.

 

In the more immediate future, one has typically seen El Niño events with Region 1+2 anomalies at or above +1.00°C produce cool anomalies in large parts of the East in August. Summer 2009 was an exception. Warmth has sometimes occurred in the Pacific Northwest and western half of the U.S.

 

In the end, it's still too soon to be sure about the upcoming winter. But if the CFSv2 is right, a cool autumn could yield to a warmer to much warmer than normal December across a wide swath of the U.S.

 

Given where things stand, one should be aware of this possible scenario, but not yet lock it in. Much can still change in Region 1+2.

 

 

Don, While it's early, it looks like your hinting at using analog years of 72,82,97, and of course I won't hold you to it as we go forward.  The question I have is related to the very warm waters in the Gulf of Alaska that we have seen the last two years.  During the summer of the years mentioned what did those waters look like?  I firmly believe that those temps have to relax if the CONUS can respond to a normal strong El Nino.  Your thoughts?

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Don, While it's early, it looks like your hinting at using analog years of 72,82,97, and of course I won't hold you to it as we go forward.  The question I have is related to the very warm waters in the Gulf of Alaska that we have seen the last two years.  During the summer of the years mentioned what did those waters look like?  I firmly believe that those temps have to relax if the CONUS can respond to a normal strong El Nino.  Your thoughts?

Not yet. I'm only stating that if the current CFSv2 idea is reasonably correct, those years might come into play. During winter 1972-73, there were warm sea surface temperature anomalies present in the Gulf of Alaska. During winters 1982-83 and 1997-98, there weren't. 1982-83 had the coolest Gulf of Alaska anomalies of those three winters.

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July 10th MEI update...

 

"The updated (May-June) MEI has risen by 0.49 standard deviations in one month to +2.06, to reach the 3rd highest ranking above the 'strong' El Niño threshold possible (upper 10%ile). This is also the highest MEI value in more than 17 years, surpassing the peak of the 2009-10 El Niño by more than 0.5 standard deviations. The current El Niño has ranked above the weak El Niño threshold for five months in a row, and above the strong threshold for three months running. Thus, it has become the first El Niño event since 1997-98 with at least three months registering in the upper 10%ile.

 

Looking at the nearest 8 rankings (+2/-6) in this season, and excluding cases with declining May-June values compared to earlier in the year gives us five 'analogues' to ponder: 1972, 1987, 1991, 1993, and 1997. All five of them attained strong El Niño status for at least three months, while 1997-98 is generally classified as a 'Super El Niño', with MEI values reaching +3 standard deviations (the only other Super El Niño of the last century occurred in 1982-83). At this point, El Niño conditions are guaranteed to persist into the upcoming boreal winter season, most likely at strong levels. If the MEI continues to rise for another month or two, even a Super El Niño is in the cards."

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3 blobs of +3C warmth off the N America and S America coasts.  June PDO from Univ. of Wash came in at 1.54.  PDO has been positive for 18 straight months, and above 1.00 for 10 straight.

 

hlXYrVg.gif

 

It's been many a year since we've seen a look like this.   Just hope the GOA warm pool persists.  It gave way quickly in the fall of '97.  If so, that'll set up for some awesome split flow opportunities.  Regardless, the STJ is going to be dominant feature this fall/winter for a change.

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