ENSO Updates (2007 thru 2023)

[Ntxw]

The weekly index shows 3.4 is at 0.5C. Should be official at the update

We know 30 day SOI has been well negative, 90 day (3 months worth) SOI has just about reached the Nino threshold.

[cycloneye]

The text of the CPC 9/15/14 update that has Nino 3.4 officially at +0.5C

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[Blown Away]

Is it safe to say this almost El Niño has been main reason for below average activity?

[WPBWeather]

Is it safe to say this almost El Niño has been main reason for below average activity?

If it is just getting there now ( a big if, IMHO) can it be the cause of things before it arrived (if it has arrived)?

[Ntxw]

Is it safe to say this almost El Niño has been main reason for below average activity?

The El Nino is not to fully be blamed, but Pacific SST configuration has not helped. Atlantic conditions were already sub par to start with for a large chunk of this season. An area that oftens contributes a good amount of activity is the Gulf of Mexico and the Caribbean. They have experienced shear especially the Caribbean likely due to the fact that Nino 1+2 has been more than warm enough since late Spring to induce shear adjacent to it. A lot of the times the gulf gets seeds for storms from waves tracking through the Carib from MDR, they have not been able to sufficiently survive the Carib this year on a consistent basis.

[NDG]

Is it safe to say this almost El Niño has been main reason for below average activity?

If it is just getting there now ( a big if, IMHO) can it be the cause of things before it arrived (if it has arrived)?

IMO, though not officially the past several months the atmosphere has behaved a lot an El Nino, besides below average named storms due to the very dry conditions at the MDR, windshear across the Caribbean this season is usually typical during an El Nino plus the high activity over EPAC, another reason.

[NDG]

Is it safe to say this almost El Niño has been main reason for below average activity?

The El Nino is not to fully be blamed, but Pacific SST configuration has not helped. Atlantic conditions were already sub par to start with for a large chunk of this season. An area that oftens contributes a good amount of activity is the Gulf of Mexico and the Caribbean. They have experienced shear especially the Caribbean likely due to the fact that Nino 1+2 has been more than warm enough since late Spring to induce shear adjacent to it. A lot of the times the gulf gets seeds for storms from waves tracking through the Carib from MDR, they have not been able to sufficiently survive the Carib this year on a consistent basis.

You are probably right, the fact that Nino 1+2 has been well above average during most of the hurricane season is probably the reason why the Caribbean has been so unfavorable.

[Ptarmigan]

Is it safe to say this almost El Niño has been main reason for below average activity?

The El Nino is not to fully be blamed, but Pacific SST configuration has not helped. Atlantic conditions were already sub par to start with for a large chunk of this season. An area that oftens contributes a good amount of activity is the Gulf of Mexico and the Caribbean. They have experienced shear especially the Caribbean likely due to the fact that Nino 1+2 has been more than warm enough since late Spring to induce shear adjacent to it. A lot of the times the gulf gets seeds for storms from waves tracking through the Carib from MDR, they have not been able to sufficiently survive the Carib this year on a consistent basis.

There also has been a lot of dry air from the Saharan Desert.

[LarryWx]

Is it safe to say this almost El Niño has been main reason for below average activity?

There also has been a lot of dry air from the Saharan Desert.

I believe that there is a rather strong correlation between oncoming El Nino's and dry air in the MDR. In other words, I think both shear and dry air in the MDR tend to be associated with El Niño.
Even though we seem to just be reaching the Niño threshold, the SOI has been solidly negative for over six weeks. That means the atmosphere has been behaving like there has already been El Niño since early August. Even if we assume a few weeks lag, that would still mean an effect on the season for September and quite possibly late August (heart of season).

[cycloneye]

CFSv2 now is projecting a multi-year Weak to Moderate El Nino extending well into 2015. Ntxw,do you think this upcoming El Nino will be a multi-year one?

[LarryWx]

CFSv2 now is projecting a multi-year Weak to Moderate El Nino extending well into 2015. Ntxw,do you think this upcoming El Nino will be a multi-year one?

I'd also like to know Ntxw's opinion. The last multiyear Nino was mid 1986 to early 1988. Prior to that, it was mid 1968 to early 1970. Others (excluding back to back like 1976-7 and 1977-8): early 1953 through early 54 (though it is borderline if this should even count), late 1939 through early 1942, possibly late 1929 through mid 1931, late 1913 through mid 1915, mid 1904-early 1906, late 1899 through early 1901, and possibly mid/late 1884 through early 1886.
So, looking back at history, one thing I can say is that we're due for a multiyear Nino. I mean it has been 26.5 years since the end of the last one, which is about as long a period as there has been between them since at least the late 1800's, even if 1953-4 isn't counted.
****EDIT: Look at it this way: we've had seven straight single fall/winter Ninos. There hasn't been this long of a streak of single fall/winter Ninos since at least the late 1800's. So, we're due for a multiyear Nino in that regard fwiw (in case are any cyclical forces in play).
****EDIT #2: I guess my take is that they haven't been all that rare in terms of frequency considering that the current streak of seven straight single fall/winter Ninos is the longest since at least the late 1800's. If I count the three that are questionable as multiyear, I count 24 singles vs. 9 multiples. 24:9 ratio is not that high. I mean that would imply more than a 1 in 4 chance that any one Nino will end up as a multiple, which is way too high to discount imo. Even if all three questionable are not counted as multiple, I still count 27 singles and six multiples. So, even with that, the implication would be almost a 1 in 5 chance that any one Nino is going to end up as a multiple. Even that would seem high enough to keep multiple as a realistic possibility.

[Ntxw]

I think sample size is quite small (going by reliable ONI) to predict a multiyear Nino. Those are some interesting numbers Larry, looks like it has a realistic chance. But realistically I wouldn't call for something with as low odds.

Using CPC ERSSTv3b back to 1950, not accounting for anything other than ONI values, here's some statistics I've gone through for the various states of Nino (weak, moderate, strong); the multiyear Nino's for this purpose I am counting as one Nino.

For this purpose since strength of Nino's can sometimes cross gray lines I've decided to set weak being anything up to 0.9C, moderate from 1.0C to 1.6C, and anything greater than 1.6C as a strong

ENSO events/years followed by Weak Nino
Neutral - 60% of the time
Nino - 20% of the time
Nina - 20% of the time

ENSO events/years followed by a Moderate Nino
Neutral - 22%
El Nino - 0%
La Nina - 77%

ENSO events/years followed by a Strong Nino
Neutral - 20%
Nino - 20%
La Nina - 60%

So by this, what happens to this Nino in the next few months will give us a hint as to what next year will bring. Given the sample is quite small. If this Nino is weak I would give the CFSv2 some more credibility, but going from a Nino of any kind to another Nino is not easy. One interesting note that even though when counted as one large Nino the two true extended Nino's 1968-1970 and 1986-1988 were actually moderate when counted single the first year (I discount 1957-1959 because JAS and ASO 1958 went below required threshold).

Side note if we remain at neutral and do not get the Nino the statistical odds of a La Nina are 0% when using the new base period. Never have we seen an official Neutral year progress into La Nina since 1950.

[cycloneye]

Thanks Ntxw as always for your great insights about ENSO that you bring. Also to Larry for his contributions.Let's see what happens with this upcoming El Nino down the road.

[cycloneye]

Here is the Mid -September update of the plume of all the ENSO models where the majority are at Weak El Nino thru the Spring of 2015.



http://iri.columbia.edu/our-expertise/c ... o/current/

[Kingarabian]

How's the PDO?

I read it was down to 0.67. A few on another forum are suspecting the +PDO is not ENSO driven, but rather, it's driven by the extreme amounts of blocking/-NPO we go early this year, which warmed the ocean.

Interesting.

But history has shown that almost all El-Nino's have warm PDO's. I think ENSO plays some kind of role. Who knows?

[gigabite]

The global warming may be having a bias on the way el Nino data is perceived. All the forecast methodologies are based on probabilities derived from recent data (during the warming trend), as the current definition of el Nino was announced Sept. 30, 2003.

If this is the beginning of a trend reversal the current methodologies may be irrelevant for a time.

[cycloneye]

A more west based El Nino coming or eventually that new warm pool at subsurface warms also the eastern equatorial Pacific and make it Traditional?

[xtyphooncyclonex]

^Niño 1+2 is rapidly warming currently.

[Ntxw]

Little change this week from all ENSO regions, 3.4 remains at 0.5C. Will be official at the update here soon.

[cycloneye]

Here is the CPC update of 9/22/14 that has no change to Nino 3.4 as it remains at +0.5C.

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf