It's Always Sunny

Ah ok that makes more sense. I saw the link you posted and it appeared to be Ray's original post I was confused. I'll check this out later. Thanks for the share!

Am I missing something?

Well for KBOS, El Nino edges out La Nina by a seasonal average (Nov-Mar) of only 0.3". WP El Nino (weak Ninos) correlate the best with productive winters for KBOS as said above. For La Nina, the data I compiled has Basin Wide and EP Nina's correlating the best. If we're talking strength, moderate Nina correlates the best by a large margin. Now as we know KBOS gets f*cked by the CF a lot so numbers probably aren't as reliable as say somewhere west of 95 where that isn't as much of a concern. Time allowing I may sample KOWD, KBED or KLWM and see what I get.

I have now included Nov-Mar average snowfall for KBOS for every composite. What was quite surprising while compiling this is that when comparing El Nino vs. La Nina as standalone, KBOS finishes with nearly the same amount of snowfall on average. I know this is only one site but wasn't expecting that. Just further proves that ENSO is one piece to the puzzle.

Yeah I'm seeing MASSIVE differences using what I'm just going to call the ONI Method. The plots correlate much better with the 500 gph plots I have. I'm using the site you are using (thanks for that, btw!). Unfortunately I don't think JRA-55 or CERA-20 gives me a precipitation option so I may just have to use NCEP for those; just about to dig into that. All in all for my new composites I've used a combo of JRA-55, CERA-20 & NCEP R1.

Going to begin re-doing my temp/precip composites for each ENSO type (EP, CP, Basinwide, etc.) using the centered 30-year base periods. I'm trying to decide if JRA-55 or ERA-5 is best but leaning towards JRA-55 since it goes back further. The dataset for ERA-5 is only from 1979-2018 so it limits me considerably. Based on what I've read so far, NCEP is not as good as these two.

I ended up caving and used 1951-2010 for the general ENSO composites and without a fixed scale due to the wide variability. As for the individual years I want to mull it over some more and decide how I want to approach that.

It's a mental hang-up for me to commit to 1951-2010 because temps are increasing so I almost feel more obligated to speak to the "new normal" if that makes sense. I love the 1951-2010 look because that's what I "know", however I continually remind myself that it likely isn't the case anymore, and according to new climo that's what shows b/c the atmos is warming and those departures that we're used to seeing aren't likely what they used to be back in the 50s-70s b/c we aren't living in that era anymore. That's why I like the approach I sent in that link last week where climo is essentially centered around the years of interest so you get a sample of both however the NOAA/NCEI site doesn't give you that flexibility. I mean honest question though would you feel inclined to say that during La Nina events the southern US should expect around average wintertime temps given what we're "used to" now? Curious to hear your input.

Added ENSO composites to my site based upon strength. 1991-2020 climo really does a number on them, especially washing out what you'd expect to be warm anomalies if you check them out. As an example using my ENSO composite for All La Nina, I'd be inclined to say during La Nina, southern/eastern CONUS is generally average temperature wise.

18Z GFS doing 18Z GFS things...

Nice posts. I've run into this observation as well while compositing everything by ENSO type, strength aside. I think(?) we can all agree that ENSO is obviously just one piece to the puzzle, and while it can hold considerable weight in "setting the baseline", that may not always be the case with other external factors in play. I do think that some ENSO phases are more reliable than others, so what I mean by that is I would put more weight in an EP La Nina playing out a certain way than say a CP La Nina as an example. Same would apply to strength.

Agreed, the daily average gives the dataset a larger sample size to work with.

RIP 2022 Hurricane Season. On to winter...wait, I forgot this sub-forum is always about winter

Past 20 years we've had some pretty high ACE seasons though but I agree about the potholes TC activity has encountered this year.

I'm taking it you're not on the Hunga Tonga train (I'm still skeptical myself)? I can't say I agree or disagree with your theory, but I'd be more inclined to think TC activity would wane over a much longer period than a one year turnaround.

Kind of going along with the topic here but being a degreed met, one thing I can't stand is when other degreed mets hold math above other people's heads in a demeaning way. Like a "I'm better than you". It's obnoxious. I've seen it on Twitter a lot and it may scare some enthusiasts away from even pursuing a degree which is unfortunate. It's essentially a subtle form of cyber bullying imo.

Well that explains why I'm such a terrible forecaster

If there's a will there's a way, especially if you have a passion for something. It's unfortunate that the intensity of college math/physics deters some people with a true passion from getting the actual degree. My program started with like 30-40 people and there were 15-20 of us who actually ended up graduating; it's a common theme everywhere. There are several people on this board that know more than some degreed mets that I know, with the only difference being they're skilled in math, when in reality most of us professional mets seldom use math in our day to day flow.

Could be a momentum budget correlation where cooler SH strato = warmer NH strato to achieve equilibrium as you said. It's a good article that definitely gets you thinking.

I finished classifying my ENSO phases as Weak, Strong or Very Strong by taking the average ONI over the NDJ, DJF, JFM periods rather than the peak. I also included trends (Strengthening, Steady or Weakening) during those three overlapping seasons since I think this is an unexplored area of study. Nothing came to light as I was doing it but I also haven't cross-analyzed them yet either. FWIW I didn't have any Strengthening episodes which I was actually a bit surprised by, especially during La Nina episodes. My composites do not line up perfectly with the listed ENSO phase due to the climo period I used, however I stumbled across this link that explains CPC's strategy of using a continually updated 30-year base period for ONI every 5 years to prevent the warming trend which has great logic. The ONI I used already has this new 30-year base period methodology applied. I may revisit my composites and experiment applying the method the CPC used but it's going to take a while so I'm in no rush to do it atm. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_change.shtml

I went through everything again and added a few more years to my dataset however I elected to keep the temp anomaly maps the same because I wasn't seeing much of a difference using 0.5 intervals vs. 1.0. Next step is to sort through weak vs strong events and see what I can pull from that.

Yeah hopefully today I am going to redo my temp anomaly maps and refine those a bit more to make some anomalies "pop". I think your approach regarding your selection of climo method is the best but I'm going to keep the 1991-2020 for mine just b/c everything else on my site has that at the moment. I'd also like to add more years to my dataset as well just to have a larger sample size of things. Good thread Paul thanks for starting this up.

I have that down as a weak La Nina as well.

That's how I approached my composites regarding SSTa, 500 gph anoms & surface temp anoms. Only exception was precip anomalies because it was far too variable so I allowed that to be a sliding interval. Using a consistent interval allows not only easier cross-analysis but also helps determine stronger vs weaker events/anomalies because everything has an equal baseline. I have Nov-Mar 2010-2011 under basin wide but regardless, I understand what you're saying; since I'm having a hard time calling something "west based", a good approach could be to call them "east leaning" or "west leaning". I like it. Once I sort through more composites again I'll probably start binning them that way as my sample size grows. Regarding the disco of using tropical forcing as a proxy for ENSO: While I think that's possible and a really good idea (and could be better than SSTa imo), I just feel like there are too many external variables that can impact velocity potential (or even OLR) anomalies beyond what is occurring in the Pacific Ocean. Also what anomaly period do you use for that which is another question. What about mean 500mb gph because then that way you don't need to use a climo period and not have to worry about SST changing. I think upper air patterns could be easily correlated with ENSO episodes but to discern what may be strong, weak or neutral could be tricky. Haven't tried it so idk but that's where my mind is heading. I've spent the past few days thinking about what climo period to use for my composites and the more I thought about it I think Paul's method makes the most sense because it classifies something "for that period in history" because it's not scientifically sound to use a current day baseline for an event that happened 60 years ago. Food for thought but maybe it's not scientifically sound to compare an ENSO event in the 1960s to one within the last decade due to the warming atmosphere (water and land temps). Not saying I agree or disagree with that but something I thought of. I like the idea of using 1950-2010 b/c it encompasses everything but 1950 vs. 2010 are also two very different time periods. Again I don't think there is a right or wrong but many subjective ways of doing it.

Yeah I don't think there is a right or wrong in something like we said is pretty subjective and we are all for the most part in the same line of thought. Anyways, I updated the La Nina composites that I already had and comparing what I had for CP La Nina versus what you had for WP La Nina they're actually pretty similar despite the years not being identical, with warmer than average temps mainly across central-eastern US, which makes sense. If you jump onto my website though you won't see that close of a correlation because I used the 1991-2020 climo which now has me contemplating changing it to maybe 1981-2010 and just keep it a sliding interval because my temp/precip anomalies are washed out because 1) I am using a -10-->10 contour interval w/ increments of 1 and 2) New climo raises ground zero so much that it's hard to discern anything unless it is "super anomalous" imo. Below are different samples of the same years, with my website image on the left, then the following two with different climos and intervals. Ahhh.