Stormchaserchuck1

Big -PNA November it looks like.. Not much of a correlation Nov going into December PNA Lite correlation to February

We do have an Aleutian ridge, -PNA, setting up for the next 10 days, Nov 5-15. After that we'll see if models are right about a transition back to +pna.

Yeah, I suspect a warmer March and probably April, just based on the trends of the last few years. I wonder if we'll transition into La Nina going into April..

Going back to the LR model accuracy that I was talking about before, now we have a colder pattern modeled, and a pretty strong +pna too. https://ibb.co/F8zkzqk Since this El Nino began, The LR GFS ensembles has been in flux more than I've ever seen before in the last 5-10 years.

The Pacific for Oct looks like an El Nino. We also have the pattern starting to show itself again on LR models. https://ibb.co/F8zkzqk Remember, we are coming off of some powerful -PNA for the last 6 years so I'll take it. https://ibb.co/FgjXKt4 I think too we've had some higher than average correlations with ENSO in satellite era, as something like 20/22 events had a +pna or -pna associated. In the early 1900s, it was not that strong.

I guess I should have focused on the Indonesia region, this is a pretty strong correlation. My point was near the dateline you had the index happening with both El Nino's and La Nina's.

I'm focused on predictive value with a lead time. Subsurface seems to work best for the PNA.

Something like OLR or 200mb, 850mb Zonal wind are higher correlated.

Measure the thing as a stand alone index. It has little predictive value for sensible weather. I just started going by the thing year-by-year. I found that the first 23 years were all alike. It's a longer term pattern or cycle, but the 1950s and 1960s were very -PNA, and that's 30% of your yearly dataset. Again, be an observer, because something is blue or red during an El Nino year doesn't mean that it isn't random. Seperate the thing out year-by-year and you find La Nina's and El Nino's both associated with similar "forcings".

It happened every year from 1950 to 1972. The average of the 23-consecutive years was greater than this year (Sept-Oct). That was a very -PNA/-PDO time. The VP caught on here as "something to correlate", but it's not by itself very correlated to the pattern.

We're getting a pretty good Kelvin Wave right now.

Looks like they did good last Winter. Even hit the Dec -NAO. I had 0"

+NAO https://ibb.co/9V9VM4h

So what? It correlates with -PNA..

The last 6 Winter's, we have had -PNA's a greater % of the time, in 3 month periods, then the last 7 months, since the El Nino developed. (I'm quantifying that 1/10 chance, and saying if you base on current probability for PNA it's about 1/3 of the 5/7 recently (5/21).

For reference, Stratosphere warmings average "downwell" time to effect Winter -AO: Oct 15-30: +60 days (Dec 15-30 -AO correlation) Oct 30-Nov 15: +45 days (Dec 15-30 -AO correlation) Nov 15-30: +40 days (Dec 25-Jan 10 -AO correlation) Dec 1-15: +35 days (Jan 5-Jan 20 -AO correlation) Dec 15-30: +30 days (Jan 15-30 -AO correlation) Jan 1-15: +25 days (Jan 25- Feb 5 -AO correlation) Jan 15-30: +20 days (Feb 5-20 -AO correlation) Feb 1-15: +15 days (Feb 15-Mar 2 -AO correlation) Feb 15-Mar 2: +15 days (Mar 1-15 -AO correlation) Mar 1-30: +10-15 days (Mar 10-Apr 15 -AO correlation) [CDC daily climate composite maps day-by-day going back to 1948.] Oct 30mb QBO should come in the next few days. Sept was -13, and down 5 from September, so Nov should come in more negative. <-10 30mb QBO and El Nino correlate strongly with Winter Stratosphere warmings (I think there is a >60% +10mb Winter correlation (NDJFM), and >+10 30mb QBO and La Nina has a >60% -10mb Winter correlation (NDJFM)). Strong 10mb vortex (Stratosphere cooling) has a +0-Day correlation to +AO from Oct 30 - Apr 5 (all Winter), no lagtime. The images posted earlier in this thread of a cold 10mb are correlating with MR/LR models showing 500mb +NAO.

We have been in this weird pattern of -EPO's and +PNA's happening with +NAO, and +EPO's and -PNA's happening with -NAO's. It's had a greater than 0.40 correlation since 2013, and 0.50 since 2019. I think our best pattern is the -EPO/+PNA/+NAO like 13-14 and 14-15, so I would watch out for that pattern probably for our snow this year. Stratosphere warmings could throw a wrench in that, I don't know how the Pacific would react or correlate in that state.

I liked the outlook. Easy to read or browse through. One point I would like to make is that things like PNA or NAO impact PDO and AMO in now-time. In other words, a +PNA Winter Dec-Feb is more likely to produce +PDO. Because of this, unless there is some alter pattern happening with the future progression of water currents, the Fall period is these best to roll forward future 500mb patterns. I think I found in the past that Sept-Nov PDO had higher than random correlation to Winter PNA, but I'm not 100% sure. I mostly agree with your temperatures, snowfall, and precip, although snowfall could go higher, given how it's solidly El Nino/max -QBO (together), and our above average precip pattern this year and for the last few years. I average 32" and the El Nino/max -QBO gives me a 40-60" range to start with, using years like 14-15.

Also, 2-3 days of cold then it's gone for 15 days. Nice Aleutian High popping up in a week. The pattern is showing signs of continuum imo. We have seen more +PNA's since the El Nino developed in April, but they are often transitory, and short lived. Will see if that trend continues.

I'm not so sold on a cold February. The last 6 February's have seen an abnormally strong -PNA, greater than you would even expect in La Nina. It's hard to imagine the pattern is suddenly going to reverse this year in El Nino, when there are no strong N Hemisphere pattern drivers right now. https://ibb.co/hysBNQj It might be one of those cases where December and February switch roles in the PNA region.

0.54 SD, at -0.05, so 50% chance of DJFM NAO range of -0.59 to +0.49, as per N. Atl SST theory [CPC].

I found that October is the only month of the year that doesn't have a +correlation to Winter NAO. There was actually a slight opposite correlation from October to DJFM at I think 52% (75 years).

The Strong Nino = warm makes no sense. Everyone is stuck on the 8-10 analog composite showing so. Why don't Strong La Nina's produce cold lol

We actually saw a drastic shift and difference in the Pacific 500mb from when the El Nino developed this year to before. +PNA is the signal going forward.

13-14 and 14-15 are decent analogs, I think (+pna, -epo, +nao). 14-15 was more +pna than 13-14, you can see how the Nino had impact.