2014 ENSO Mega Thread

[The_Global_Warmer]

Friv,

 Nothing too exciting. After tomorrow's # being pretty close to the -1 to +3 range, today's 0Z Euro is suggesting a small positive is most likely for 9/6. Then it suggests mainly small -SOI's for most, if not all of, 9/7-13 followed by perhaps a rise to a small +SOI around 9/14.

 

What does that normal equate too?

 

Do you have the links to the forecasted equatorial winds?  I have looked everywhere for them that have been posted here before but can't find them.

 

Sounds like the Euro forecast would be for neutral conditions of some sort.

[The_Global_Warmer]

 Thanks. 1992 and 1993's -SOI strings tell me to not bet the ranch on Nino based on the current 32 day string and to leave open the chance for a high end neutral positive. However, the overall impression I get from this SOI data is that a weak Nino is likely. I'm now going from high end neutral positive through low end moderate to cover the vast majority of possibilities with weak Nino dominating in the middle.

 

Do you think the recent volcanic eruption had to do with that?  Possible causing more to down cooling then what normally would have taken place?

[GaWx]

What does that normal equate too?

 

Do you have the links to the forecasted equatorial winds?  I have looked everywhere for them that have been posted here before but can't find them.

 

Sounds like the Euro forecast would be for neutral conditions of some sort.

 

 I'd say that this supports the current warming and that it will likely at least keep Nino 3.4 from cooling off much anytime soon since I see no period of solid positives anytime soon. The prior 32 days of -SOI are dominating for the time being. As my stats show, it never stays negative as at least short lived +SOI intervals are common due to normal fluctuations in SLP's at Darwin/Tahiti.

 

 No, I don't have that link.

[GaWx]

Do you think the recent volcanic eruption had to do with that?  Possible causing more to down cooling then what normally would have taken place?

 

 I have no idea. Interesting hypothesis though.

[bluewave]

The only thing that I can say about the August trade wind behavior is that it was different

from -SOI Augusts which preceded El Nino events during the 2000's so far. Normally 

you would expect a westerly wind burst pattern to emerge over the Western Pacific

to around the Dateline. This August the westerly wind burst pattern was closer

to the Eastern Pacific. 

 

2014

 

 

August -SOI composite before El Nino

 

 

 

[Kory]

The only thing that I can say about the August trade wind behavior is that it was different

from -SOI Augusts which preceded El Nino events during the 2000's so far. Normally

you would expect a westerly wind burst pattern to emerge over the Western Pacific

to around the Dateline. This August the westerly wind burst pattern was closer

to the Eastern Pacific.

What affect do you think that'll have on this Nino if any? Does a west wind burst closer to the eastern Pacific help a more traditional Nino to occur with the warming happening more in the eastern Pacific?

[griteater]

Early Sept release of the MEI is out.  The Jul/Aug MEI ranking falls into the moderate El Nino category.

 

Here are the MEI rankings back to the start of the year:

 

Jan/Feb: Neutral

Feb/Mar: Neutral

Mar/Apr: Neutral

Apr/May: Moderate Nino

May/Jun: Weak Nino

Jun/Jul: Weak Nino

Jul/Aug: Moderate Nino

[AlaskaETC]

This map may be good in looking at the currents:

 

http://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=231.35,11.88,673

[The_Global_Warmer]

Pretty large sub-surface warm pool still strengthening and heading East.  Stretching over most of the Equatorial Pacific.

 

 

 

 

 

[GaWx]

Per the 0z Euro, the next 10 days will be dominated by -SOI's. (~9/11 may be barely +). This along with the subsfc continues to support warming toward a weak Niño ONI peak (to possibly low end mod) this fall/winter. This along with good prospects for +PDO bodes well for those who want a cold winter in much of the E US as long as we can get -NAO then.

[uncle W]

 mei index went up a bit to +.858 making it the fourth two month period in a row that was in weak el nino territory...

http://www.esrl.noaa.gov/psd/enso/mei/table.html

JMA is on par with 2009...

ftp://www.coaps.fsu.edu/pub/JMA_SST_Index/jmasst1868-today.filter-5

[GaWx]

mei index went up a bit to +.858 making it the fourth two month period in a row that was in weak el nino territory...

http://www.esrl.noaa.gov/psd/enso/mei/table.html

JMA is on par with 2009...

ftp://www.coaps.fsu.edu/pub/JMA_SST_Index/jmasst1868-today.filter-5

I use the JMA as one of my tools to determine pre-1950 ENSO. It (mamjj) is on par with 2009. However, just to clarify, the +0.7 is based on 90-150W, 4n-4s (very similar to niño 3 but can be bit warmer than 3 since doesn't extend as far n/s of equator) vs 120-170w of 3.4. The new JMA # of +0.7 is based on avg of mamjj. The mamjj of 3.4 would be closer to only +0.2 to +0.3. My guess is that JMA will warm more next 2-3 months to perhaps near +1.0. However, the jason # may actually cool back some due to losing the warmest month to date of June, which likely was near +1.1 in JMA.

[Isotherm]

August's SOI value of -11.4 is highly suggestive of at least a weak el nino for the ensuing winter. The strong el nino of 2009-10 actually didn't have an SOI monthly value below -10 until October. 1986-87 did not have a sub -10 month until November. The weak-mod Nino of 1963-64 had its first sub -10 month in October.

 

The point is, while this Nino event is intensifying later than earlier projections from the spring, we're certainly far from "late to the game" with respect to the development of a weak El Nino.

[Dsnowx53]

Per the 0z Euro, the next 10 days will be dominated by -SOI's. (~9/11 may be barely +). This along with the subsfc continues to support warming toward a weak Niño ONI peak (to possibly low end mod) this fall/winter. This along with good prospects for +PDO bodes well for those who want a cold winter in much of the E US as long as we can get -NAO then.

The GFS agrees, and seems to imply that September could have a SOI more negative than August. I got this image from Michael Ventrice's twitter account, btw.

[The_Global_Warmer]

The GFS agrees, and seems to imply that September could have a SOI more negative than August. I got this image from Michael Ventrice's twitter account, btw.

soi.gif

 

From most of what I read on here.  These Kelvin waves roll thru then there is a break.

 

Does this mean another Kelvin wave will form right behind the one that has been traversing the Equatorial Pacific or like a continuous situation?

 

Also what effect does the seasonal solar change have on ENSO?

[Dsnowx53]

From most of what I read on here.  These Kelvin waves roll thru then there is a break.

 

Does this mean another Kelvin wave will form right behind the one that has been traversing the Equatorial Pacific or like a continuous situation?

 

Also what effect does the seasonal solar change have on ENSO?

It could. The fact that we have sustained -SOI with this Kelvin Wave means that the atmosphere is finally responding and is taking more of an El Nino state. This favors the El Nino feedback mechanisms that generate weaker trade winds, more Kelvin Waves, and warmer SSTs.

We didn't get the sustained SOI drop with the last really strong Kelvin Wave. This was a factor in the atmosphere not responding. That way, once the Kelvin Wave passed through, there was nothing to keep any El Nino conditions going, so the warm pool sloshed back to the west.

Of course, there is more to it than the SOI, but I think it tells a decent chunk of the story.

Edit: I can't tell you about the solar change, unfortunately.

[Kory]

Interesting that Nino 3.4 and 4 didn't increase.  Still stagnant at +0.4 C and +0.5 C respectively.  There is some significant subsurface warming ongoing.  Nino 1 and 2 did increase, which is likely responsible for the uptick in Caribbean shear. 

[Isotherm]

-24 daily SOI now. Should see another westerly wind burst and consequently gradually warming SST's in the Nino regions 3.4 + 4. I anticipate that the critical regions will be +0.5c to +1.0c within the next 4 weeks or so.

 

Given the historical timing and progression of this event, I think there's solid evidence for a peak trimonthly value around or just under the moderate threshold (maybe +0.8c or +0.9c). The late warming of the ENSO regions could be similar to events such as 04-05, 06-07, 76-77, 77-78, 68-69, and 94-95 -- talking +ENSO timing/onset alone, excluding all other factors.

 

Weak Nino seems like a lock at this point to me. Only question in my mind is do we kiss / enter the low-end moderate range.

[nflwxman]

-24 daily SOI now. Should see another westerly wind burst and consequently gradually warming SST's in the Nino regions 3.4 + 4. I anticipate that the critical regions will be +0.5c to +1.0c within the next 4 weeks or so.

 

Given the historical timing and progression of this event, I think there's solid evidence for a peak trimonthly value around or just under the moderate threshold (maybe +0.8c or +0.9c). The late warming of the ENSO regions could be similar to events such as 04-05, 06-07, 76-77, 77-78, 68-69, and 94-95 -- talking +ENSO timing/onset alone, excluding all other factors.

 

Weak Nino seems like a lock at this point to me. Only question in my mind is do we kiss / enter the low-end moderate range.

Even a weak/slightly moderate Nino will help the southern stream come January.  While the start of this nino is little later than usual, it should still impact weather nicely in DJF.

[Kory]

Some serious subsurface warming going on the Central Pacific with +4 degree C anomalies showing up.  Probably several weeks away before we see them start to surface.  Looks like this Nino will come to fruition, although not as strong as forecasted back in spring. 

 

[IntenseBlizzard2014]

Is Nino 1 + 2 going to cool down even further? 

[stadiumwave]

Is Nino 1 + 2 going to cool down even further? 

 

Eventually...but it will be slow.  I'm thinking December will be mild for a chunk of U.S. but as warmer waters slowly move west by end of December into January it will get fun for several weeks.

[bluewave]

Despite the -SOI drop, the trades still haven't relaxed over the Western Pacific.

My guess is that the very warm SST's over the Western Pacific could be the

reason as the Western Pacific Warm Pool  promotes stronger trades as seen

below. I think that a weak El Nino range tri-monthly may be the strongest

we can see if these trades don't eventually relax. But we'll have to see

how things progress as we head into October.

 

 

 

 

 

[Kory]

Does anyone think the very warm waters in the Western Pacific could be signaling a change from the +PDO we've been seeing to perhaps a more neutral to even negative phase?  If you look at the SST anomalies, the Pacific looks very neutral currently...not nearly as positive as we've seen the past several months.  I don't want to hijack this thread, but if we are switching back to a negative phase, it could explain why we've been struggling with this Nino, which looked like a slam dunk just a few months back.  

[ORH_wxman]

Despite the -SOI drop, the trades still haven't relaxed over the Western Pacific.

My guess is that the very warm SST's over the Western Pacific could be the

reason as the Western Pacific Warm Pool  promotes stronger trades as seen

below. I think that a weak El Nino range tri-monthly may be the strongest

we can see if these trades don't eventually relax. But we'll have to see

how things progress as we head into October.

 

Screen shot 2014-09-10 at 7.22.40 AM.png

 

WP.gif

 

 

It looks like a WWB is trying to get going on the latest update...the forecast is for it to propagate eastward over the next 5 days. It's not overly strong, but its a reversal from the easterly winds that preceded it.

 

[GaWx]

Does anyone think the very warm waters in the Western Pacific could be signaling a change from the +PDO phase we've been seeing to perhaps a more neutral to even negative phase? If you look at the SST anomalies, the Pacific looks very neutral currently...not nearly as positive as we've seen the past several months. I don't want to hijack this thread, but if we are switching back to a negative phase, it could explain why we've been struggling with this Nino, which looked like a slam dunk just a few months back.

Based on what I've read, we're still in a -PDO REGIME despite the recent +PDO months. I believe we're still +PDO PHASE based on U of Washington calc by the way because the average anomaly along and near the dateline is still cooler than the still warm E Pacific average anomaly. Warmth well to the west of the dateline really doesn't do much to lower the PDO based on the definition/calc. Anyway, -PDO regimes have been found to have less frequent strong El Ninos because of the -PDO regime sort of fighting back against Niño. However, this seems to have resulted in increased weak Niño frequency despite decreased strong niño frequency because what would have resulted in strong instead settles at weak in some cases.

[Kory]

Based on what I've read, we're still in a -PDO REGIME despite the recent +PDO months. I believe we're still +PDO PHASE based on U of Washington calc by the way because the average anomaly along and near the dateline is still cooler than the still warm E Pacific average anomaly. Warmth well to the west of the dateline really doesn't do much to lower the PDO based on the definition/calc. Anyway, -PDO regimes have been found to have less frequent strong El Ninos because of the -PDO regime sort of fighting back against Niño. However, this seems to have resulted in increased weak Niño frequency despite decreased strong niño frequency because what would have resulted in strong instead settles at weak in some cases.

You can also look at the waters by Japan, which has warmed considerably since May (the highest PDO reading of 2014).  But they're still cooler than the Eastern Pacific like you mentioned.  

[GaWx]

You can also look at the waters by Japan, which has warmed considerably since May (the highest PDO reading of 2014). But they're still cooler than the Eastern Pacific like you mentioned.

Yeah, Japan is too far west to affect the PDO calc. The average anomaly of the box within 30 degrees longitude and 20 degrees latitude of 40N on the dateline is the most important area in the calculation of the comparison to the E Pacific for at least the U of Washington version. There's little question in my mind that that box's average anomaly is still a good bit more negative than the E Pacific.

So, the PDO is not so much an eastern North Pacific vs western N Pacific comparison. It is more of an E N Pacific vs central N Pacific comparison.

[Bob Chill]

Yeah, Japan is too far west to affect the PDO calc. The average anomaly of the box within 30 degrees longitude and 20 degrees latitude of 40N on the dateline is the most important area in the calculation of the comparison to the E Pacific for at least the U of Washington version. There's little question in my mind that that box's average anomaly is still a good bit more negative than the E Pacific.

So, the PDO is not so much an eastern North Pacific vs western N Pacific comparison. It is more of an E N Pacific vs central N Pacific comparison.

There was a slight improvement in the pdo region on the latest ssta chart compared to the first of the month. The nice +pdo we had going basically collapsed to neutral as summer progressed. No way of really knowing whether the fall to neutral has bottomed out and will rise again or continue downward.

However, GEFS and euro ens both agree that the height patterns will favor cooling of both the ne & nw pac over the next couple of weeks. Of course a couple of weeks doesn't mean that much over the longer term. Just something to watch over the next few weeks and see how ssta's respond.

I'm interested to see how big of a dent the warm pool in the goa takes over the next 2 weeks. I'm not that hung up on that area staying warm. I would much rather see a pronounced move towards a more classic nino sig in both the enso and pdo regions over the next 2 months or so. Right now the npac as a whole is much warmer in early september than any of the last 4 nino years. The closest match would be 2004 but there are stark differences in the wpac.

[GaWx]

There was a slight improvement in the pdo region on the latest ssta chart compared to the first of the month. The nice +pdo we had going basically collapsed to neutral as summer progressed. No way of really knowing whether the fall to neutral has bottomed out and will rise again or continue downward.

However, GEFS and euro ens both agree that the height patterns will favor cooling of both the ne & nw pac over the next couple of weeks. Of course a couple of weeks doesn't mean that much over the longer term. Just something to watch over the next few weeks and see how ssta's respond.

I'm interested to see how big of a dent the warm pool in the goa takes over the next 2 weeks. I'm not that hung up on that area staying warm. I would much rather see a pronounced move towards a more classic nino sig in both the enso and pdo regions over the next 2 months or so. Right now the npac as a whole is much warmer in early september than any of the last 4 nino years. The closest match would be 2004 but there are stark differences in the wpac.

To get back to a more solid +PDO, I'd like to see the Aleutian waters cool back down.