ENSO breakdown

[weatherwiz]

I am working on my senior research and I am stuck with something and I was hoping to get some guidance/opinions/suggestions from here...and this will be incorporated within my presentation/paper in terms of sourcing. 

Unless anyone is interested I will refrain from explaining the total jest of my research...1) to spare the boredom and 2) it would make this post longer than needed. 

Anyways, to simply I am doing my research involving tornadoes and I am focusing on the spring. Within my research I will be putting a focus onto ENSO and what I would like to do is breakdown ENSO not only into phase but the strength of the phase as well as where the anomaly was centered (so like west-based, east-based, central, etc). 

What I am struggling with is coming up with a threshold for doing these breakdowns and this is due to the atmospheric-oceanic lag that exists. Let's look at 1972-1973, for example. That winter was a strong EL Nino (well super-strong) but by definition, it officially ended in the FMA trimonthly period and by that point it was weak. So keeping in mind my my focus is spring (MAM). So, what would be the best way to classify that spring into? 

Maybe there is just no way to directly quantify an event just b/c of the variability in strength and the unknown with regards to the atmospheric-oceanic lag. 

If needed, I can explain what my vision is further and any input/suggestions will be sourced within my presentation. 

[raindancewx]

I generally classify ENSO events by DJF anomalies for the entire July-Jun period, so long as the classification lasts for more than six months between July-June since the leading indicators of a winter La Nina or El Nino (SOI, subsurface, pattern changes) will start to show up before the classification begins. In Spring, like Fall, you have less variation in ONI magnitude, there is no -2 or +2 three-month period like you can have in winter. So it becomes less of a big deal that a lot of the weak La Nina or El Nino events in MAM are only +0.2 or -0.3, etc in Spring.

[weatherwiz]

4 minutes ago, raindancewx said:

I generally classify ENSO events by DJF anomalies for the entire July-Jun period, so long as the classification lasts for more than six months between July-June since the leading indicators of a winter La Nina or El Nino (SOI, subsurface, pattern changes) will start to show up before the classification begins. In Spring, like Fall, you have less variation in ONI magnitude, there is no -2 or +2 three-month period like you can have in winter. So it becomes less of a big deal that a lot of the weak La Nina or El Nino events in MAM are only +0.2 or -0.3, etc in Spring.

Thanks for the input! This makes a tremendous amount of sense especially considering the ENSO seems to be strongest during the northern hemisphere cool season. So maybe for my purpose I should just focus on like the DJF and JFM periods? 

I think my issue here is I just want to be too perfect and sort of "over-analyze". FWIW, in my conclusion I also plan on explaining the limitations within my research and explaining how these limitations can be explored further 

[40/70 Benchmark]

I encountered the same issue earlier this saeason. I decided to consider the modoki value during the tri monthly peak...aka, if we had a NDJ peak, then I use the modoki value for that particular period.

[weatherwiz]

On 10/30/2018 at 9:47 AM, 40/70 Benchmark said:

I encountered the same issue earlier this saeason. I decided to consider the modoki value during the tri monthly peak...aka, if we had a NDJ peak, then I use the modoki value for that particular period.

From what I've gathered through various papers this seems to be a popular method.