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Weak-Moderate El Nino 2018-2019


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5 hours ago, griteater said:

Updated with Oct data now in

wLxD99M.png

#hybrid

The Sept/Oct MEI value actually took a dip from Aug/Sept.

2018	-.623	-.731	-.502	-.432	.465	.469	.076	.132	.509	.468

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

That is my main issue with 1957 (1.068), 1986 (.96), 2002 (.979) and 2009 (.883) as viable analogs for 2018 (.468).

Its going to be more N stream than those seasons.

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18 minutes ago, 40/70 Benchmark said:

I'm not advocating for that particular analog's utility....but I see you speak in absolutes like this quite often....."if A means anything, then B will happen"....meteorology does not work like that. Not only are there a plethora of other factors that modulate weather on a seasonal basis, but there are anomalies, as well. Sometimes you have A+B...but the atmosphere just refuses to $hit out C but atmospheric responses can simply be stochastic in nature, as well. It does not mean that a correlation/relationship doesn't exist, and you shouldn't expect C the next time.

Solar implications are very worthy of consideration, regardless of whether or not winter 1957-1958 proves a viable analog for winter 2018-2019-

His use of "A leads to B" kind of rubs me wrong for the reasons you mention here. We have to be careful in atmospheric science to not over explain things that happen to be correlated based on small sample sizes.

 

Don't get me wrong raindancewx, I like your posts! Just be more careful with your word choice.  

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3 hours ago, raindancewx said:

My main issue with 1957 as an analog is you had near record solar activity that year, near 300 on an annualized basis from July 1957 to June 1958. So if solar means anything, some kind of different outcome would be expected. Obviously it is running much warmer than the blend in the NE as of right now too.

I've looked at solar effects by elevation and ENSO in the West, and it seems like the primary effect is on temperature in winter/summer, and on precipitation in fall/spring. March in the SW is kind of flaky for snow, but high solar does seem to be almost a pre-requisite for Albuquerque to get heavy snow in March.

I just looked at Philadelphia snow in El Nino by solar conditions - no correlation. So maybe watch early December? I have a hunch that a blend of 1986/1994/2006 will show up as the Dec pattern though.

So those 3 years 86 94  2006 are those your analog years for the winter 2018/19

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4 minutes ago, BlizzardWx said:

Years like 2014 and 1968 were pretty much exact opposites for my area. ECMWF seasonal forecast is looking much more 2014 like for my part of the country. 

Probably more PNA and less NAO than 1968....and more NAO and maybe a bit less PNA than 2014. I don't mean either analog is perfect, but I think the predominate form of cyclogensis maybe similar to those years.

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8 minutes ago, BlizzardWx said:

His use of "A leads to B" kind of rubs me wrong for the reasons you mention here. We have to be careful in atmospheric science to not over explain things that happen to be correlated based on small sample sizes.

 

Don't get me wrong raindancewx, I like your posts! Just be more careful with your word choice.  

Yea, I don't agree with a lot of his assertions regarding this season, but he is an asset to the forum and possess a wealth of knowledge.

Very good poster.

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My ideas with analogs are pretty complicated, but basically I see every year like the prime number theorem.

Say 1957 is 10. You can make 10, with 5 x 2 most simply.

Say 2004 is 25. You can make 25 with 5 x 5 mostly simply. 

So if the 5 is what drove the snow storm he was talking about in 1957, then you'd look for it in other analogs with the same components, i.e. the same ocean temps, ENSO order, weather patterns, etc, but low solar, and then see if it snowed. I have a system that allows me to do that. So when I say X caused Y, I'm saying that because I tried to isolate all the other things that have high correlations to what I'm trying to predict. 

My system looks at Nino 3.4 SSTs, Nino 3.4 in the prior year, the AMO, the PDO, the monsoon in the SW, Modoki structure, and the sun. That's it. Then I match a blend to my weather conditions, and whatever blend the computer makes that works over the longest time frame, that is the one I roll forward. So basically, when I put in all the 1957 conditions, but lower sunspots, and score the most similar years, these are the Ninos that pop out -

2009, 1953, 2006, in that order. Here are figures for 2009 and 1957, ONI is constant against a long term base.

Years ONI DJF AMO N-A SUN Jul-J ONI DJF(p) Modoki PDO N-A Monsoon
2009 1.5 0.200 13.2 -0.9 0.77 0.43 3.96
1957 1.4 0.193 281.6 -0.5 0.68 0.22

3.80

So for Philly in Decembers like 1957, but with low sunspots....you get 24" in 2009, which is obviously a lot for December, and then 0 in the other two years, 2009 is the closest though if the pattern were to go to 1957 but with low solar. So maybe you look for a big snow event in early Dec? That's kind of the way I use analogs.

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The other aspect of forecasting that I love is that not only is the atmosphere filled with chaos and often unpredictable, but each individual forecaster's style and methodology is unique and eclectic.....which given the inherent stochastic nature of the atmosphere, is splendidly app pro po.

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10 hours ago, BlizzardWx said:

Years like 2014 and 1968 were pretty much exact opposites for my area. ECMWF seasonal forecast is looking much more 2014 like for my part of the country. 

It's because 1968-1969 basically acted like a La Niña in many respects. It had a deeply negative PNA. 

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Here is an update on the subsurface. Still migrating east and "up" to the surface. Those +5 to +6C waters look like they'll come in Nino 3 or 1.2 within a month or two.

Equatorial Pacific Temperature Depth Anomalies Animation

SOI has been falling off again too. 1957/1986 both were similar for the SOI in July, Aug, Sept, Oct, but each dropped to around -12 in November, and that doesn't seem to be coming for November with the SOI at -1.3 for 1/4 of November.

Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI
8 Nov 2018 1010.65 1007.95 -1.15 4.28 -2.98
7 Nov 2018 1010.91 1008.15 -0.77 4.17 -3.31
6 Nov 2018 1011.79 1008.90 0.06 3.93 -3.48
5 Nov 2018 1011.99 1009.50 -2.48 3.72 -3.49
4 Nov 2018 1012.21 1010.15 -5.22 3.72 -3.58
3 Nov 2018 1012.54 1011.10 -9.17 3.97 -3.80
2 Nov 2018 1013.42 1010.50 0.25 4.50 -3.84
1 Nov 2018 1014.56 1010.35 8.46 4.27 -3.91
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2 hours ago, griteater said:

Nino 3.4 / Modoki Index over the last 5 days (Daily AVHRR Data)

11/8: 0.69 / 0.61

11/7: 0.85 / 0.73

11/6: 0.84 / 0.65

11/5: 0.94 / 0.55

11/4: 1.13 / 0.86

Nor do I foresee any imminent ascension to moderate status...the classic STJ dominant seasons like 1986, 2002 and 2009 were significantly stronger by this point. Even if this event were to mutate, and intensifies until next fall, we are running out of time to maintain relevance for this particular cold season.

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1 hour ago, 40/70 Benchmark said:

Nor do I foresee any imminent ascension to moderate status...the classic STJ dominant seasons like 1986, 2002 and 2009 were significantly stronger by this point. Even if this event were to mutate, and intensifies until next fall, we are running out of time to maintain relevance for this particular cold season.

Would you then say weaker Nino = colder winter overall ? versus 02-03 and 09-10 possibly ?  

And maybe certain areas will simply have more snow ( above climo )  due to more frequent events,  ( even with less -NAO ) versus years like 02-03 and 09-10 that had HECS / MECS and contributed so much to the overall snowfall totals.  

I still like the overall manner in which the SSTs seem to favor keeping the MJO out of the super warm phases. That could change though at some point.   

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35 minutes ago, frd said:

Would you then say weaker Nino = colder winter overall ? versus 02-03 and 09-10 possibly ?  

And maybe certain areas will simply have more snow ( above climo )  due to more frequent events,  ( even with less -NAO ) versus years like 02-03 and 09-10 that had HECS / MECS and contributed so much to the overall snowfall totals.  

I still like the overall manner in which the SSTs seem to favor keeping the MJO out of the super warm phases. That could change though at some point.   

I think this winter will be colder than the average moderate el nino, but not necessarily colder this season due to el nino being weak, as opposed to moderate, if that makes sense?

Without having run statistical regression, I am fairly certain that DM temp is modulated more by modoki value, than strength...caveat being that stronger events rate lower on the modoki value. So while it appears strong events are all warm...its because they are usually east based. However the stronger events that were modoki events are still cold (57-58, 65-66, 2009-10). The aforementioned strong modoki events also usually have weaker MEI values, which is probably not a coincidence. Additionally, we have weak events that are more east based that were warm, like 2006-07.

As far as precip, weak events are more n stream dominant...Miller B, which can still be very good in the mid atl, but 2010 is not walking through that door.

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One of my beefs with NOAA is they use such different "base periods" for ONI, without easily acknowledging how volatile those 30 year means are. So for October 2018, the Nino 3.4 reading against a constant average (1951-2010) is a lot like some of the stronger (not Super) El Ninos.

1986, 1991 - both pretty healthy El Ninos - are very similar to October 2018. My research also implies the peak was not likely in October, so Nov-Jan, one of those months, maybe Feb, is likely to be a higher anomaly v. 1951-2010.

y0g7Laj.png

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5 hours ago, raindancewx said:

Simple thing...but given the subsurface waters are still very warm and migrating East...the very first observation from the Peruvian fishermen of yore about El Nino may hold true this year - the waters off Peru may peak in anomalous warmth around Christmas.

They can do whatever they want at Christmas. Doesn't matter to me

 

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Looks to me like ~80% of the Euro guesses on Nino 3.4 have this event peaking at +1.0 to 1.5C for DJF. Very few show a weak event now, very few show a strong event. Worth noting the event may still be around +1C in May, which is quite rare - only 1982, 1986, 1991, 1997, 2014 were like that in recent years. Most of those years were two year or Super El Ninos. In the extended data 1940 would be another example since of a Nino that was still very strong the following May.

EW3g6Rq.png

The 11/1/17 run did well last year, but the La Nina was forecast to be dead by May (which happened) unlike this year.

imRgkyM.png

Most of the guesses have Nino 1.2 reaching similar strength as Nino 3.4, which would make this a basin wide El Nino. My definition for that is all anomalies (1.2, 3, 3.4, 4) are with 0.2 of Nino 3.4. 

ulkyyOw.png

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2 hours ago, raindancewx said:

Looks to me like ~80% of the Euro guesses on Nino 3.4 have this event peaking at +1.0 to 1.5C for DJF. Very few show a weak event now, very few show a strong event. Worth noting the event may still be around +1C in May, which is quite rare - only 1982, 1986, 1991, 1997, 2014 were like that in recent years. Most of those years were two year or Super El Ninos. In the extended data 1940 would be another example since of a Nino that was still very strong the following May.

EW3g6Rq.png

The 11/1/17 run did well last year, but the La Nina was forecast to be dead by May (which happened) unlike this year.

imRgkyM.png

Most of the guesses have Nino 1.2 reaching similar strength as Nino 3.4, which would make this a basin wide El Nino. My definition for that is all anomalies (1.2, 3, 3.4, 4) are with 0.2 of Nino 3.4. 

ulkyyOw.png

These are monthly anomalies, not ONI.....secondly, it really doesn't matter by January.

I'm sure at some point, modoki and its attendant forcing will relinquish influence in the atmosphere, but the key is that it should be prevalent for the vast majority of boreal winter 2018-2019.

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Isn't the working theory that Modoki forcing is supposed to make the East Coast cold? Shouldn't the East Coast...be cold? 

Albuquerque running 5F colder than Boston in November isn't exactly consistent with Modoki forcing to me. We should have lows around 20F this week with highs in the upper 30s on Monday which is 15-20F below average out here for November. The cold this week will come close to locking us in for another cold month. 

At a very simple level, the pattern is opposite last year right? Last year was an East-based La Nina. This year is an El Nino, and not East-based, whether that's a hybrid, basin-wide, or Modoki, it isn't East-based. The NE was cold in Dec 2017. So I have warm. The NE was volatile in Jan, it looks fairly quiet on the models. Feb was warm, so it will be cold. March was crazy cold and stormy...well you get the idea. Opposite.

The stuff I see for March is about the strongest signal from independent things I've ever seen for cold in the SW, the super +NAO in Oct favors cold in the SW in March, the huge remnant E Pacific hurricane rains in October and August favor cold in the SW, the major hurricanes hitting the Gulf Coast in an El Nino favor cold/wet March, the cold highs in BOTH Oct and Nov favor cold March too. 

My coldest winter highs here are El Ninos after a La Nina with low solar. This is based on a regression of all El Nino events from 1931-2017, and then I tested it on 1892-1930 El Ninos and it still worked about as well as in the more recent period. The reason I single out 1963 and 1994 is those are the only years in the 1931-2017 period when the regression is out over 2F, and they had volcanic effects. 1991 is third worst, and the volcanic years in 1892-1930 are similarly bad hindcasts.

The history here says when an El Nino develops after a La Nina, the cold develops almost immediately and persists, often for 3/5 months, 6 out of 7, 9 out of 11, that kind of thing. The El Nino developed in Sept/Oct...and highs have been cold since October. The closest blend on Nino 3.4 DJF (+1.2), Nino 3.4 the prior winter (-0.9), and annualized low solar (6 sunspots) is something like 1963, 1965, 1976, 1986, 1994, 2006, 2009. I suspect that blend will be quite close for the SW, even though it won't work nationally since so many of those years are different in the AMO (NE)/PDO (SE/NW) zones, which impact temperatures elsewhere, but not here. They are both precipitation signals here.

Year    ONI    Sun   ONIp
1963    1.1    29.1    -0.4
1965    1.4    37.1    -0.6
1976    0.7    23.2    -1.6
1986    1.2    19.1    -0.5
1994    1.0    36.9    0.1
2006    0.7    20.1    -0.8
2009    1.5    13.2    -0.8
Mean    1.1    25.5    -0.7

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