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Pattern ENSO Updates

I dont know if we are headed to la Nina or not, but i do believe we are headed towards Neutral which ill be happy with. I was reminded earlier that 92/93 blizt/snows were in neutral year with a warm biased ENSO neutral. So thats why either weak nino or neutral would fit better for this year.
 
accu35 said:
I dont know if we are headed to la Nina or not, but i do believe we are headed towards Neutral which ill be happy with. I was reminded earlier that 92/93 blizt/snows were in neutral year with a warm biased ENSO neutral. So thats why either weak nino or neutral would fit better for this year.
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Considering how warm current Niño 3.4 SST anomalies are (still up near +0.5 as of the last weekly), it is highly unlikely it cools enough to get to La Niña territory by this winter. I'm currently thinking either warm neutral or weak El Niño is most likely. I had earlier thought weak to low end moderate El Niño was the most likely but July's SOI in combination with the recent 0.2 SST drop has lowered that chance in my mind. I still see no return on the models to sustained -SOIs like we had in June.
 
GaWx said:
With TAO and the weeklies having recently cooled 0.2+ and the July SOI headed for a sold +, I have no choice but to reduce the odds in my mind for an oncoming El Nino this year. Previously, I had said the chances were "very good".

If one wants El Nino, one cannot like how high Tahiti's SLP is going to end up this month. For 7/1-20. it is averaging 1015. I'm projecting it will approach or even reach 1019 tomorrow and still be near 1018 the day after. Here are my educated guesses for the rest of the month based on the 12Z models:

7/21: 1019
7/22: 1018
7/23: 1016.5
7/24: 1015
7/25: 1014.5
7/26: 1014
7/27: 1014.5
7/28: 1015
7/29: 1015
7/30: 1015

If the above projections were to come close to verifying, the full July 2017 Tahiti averaged SLP would come out to ~1015.2, which is a full mb above the longterm average for all years since 1950. That 1015.2 may even be a little conservatively low as the EPS would imply that it get up to ~1015.35. Here are some Tahiti averages for various oncoming ENSO:

Strong Nino: 1013.4
Weak to Mod Nino: 1013.9
Weak to mod Nina: 1014.3
Strong Nina: 1015.2

So, Tahiti's 2017 SLP is now projected to come in near the average for an oncoming strong La Nina. As a matter of fact, every single instance of Tahiti being 1015.0+ in July since 1950 (8 of them) was an oncoming La Nina year. OTOH, every single one of those 8 cases had an AMJ trimonthly Nino 3.4 that was negative vs 2017's +0.5. So, I'm not at all saying it means we're likely headed for La Nina. But I am saying that the chances for El Nino have dropped quite a bit in my mind over the last month. Consider this: for every El Nino since 1950 that was oncoming (24 of them), Tahiti's SLP was never higher than 1014.7!
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For the 1st 3 days, my educated guesses for the Tahiti SLP based on the 12Z models of 7/20 are averaging 0.9 too high. If I were to assume that the remaining days of July were to also come in 0.9 lower than those projections, the full July SLP would be near the 1014.9 to 1015.0 range rather than my projected 1015.2. That would still be relatively high for July (still not at all suggestive of an upcoming El Niño), but not as extreme as 1015.2. For comparison purposes, the highest July Tahiti SLP for the 24 oncoming El Niño's since 1950 was only 1014.7.
 
GaWx said:
For the 1st 3 days, my educated guesses for the Tahiti SLP based on the 12Z models of 7/20 are averaging 0.9 too high. If I were to assume that the remaining days of July were to also come in 0.9 lower than those projections, the full July SLP would be near the 1014.9 to 1015.0 range rather than my projected 1015.2. That would still be relatively high for July (still not at all suggestive of an upcoming El Niño), but not as extreme as 1015.2. For comparison purposes, the highest July Tahiti SLP for the 24 oncoming El Niño's since 1950 was only 1014.7.
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Wow, thanks Larry
 
GaWx said:
For the 1st 3 days, my educated guesses for the Tahiti SLP based on the 12Z models of 7/20 are averaging 0.9 too high. If I were to assume that the remaining days of July were to also come in 0.9 lower than those projections, the full July SLP would be near the 1014.9 to 1015.0 range rather than my projected 1015.2. That would still be relatively high for July (still not at all suggestive of an upcoming El Niño), but not as extreme as 1015.2. For comparison purposes, the highest July Tahiti SLP for the 24 oncoming El Niño's since 1950 was only 1014.7.
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Using CRU BOM Tahiti MSLP, I actually found 6 Julys with as high or higher MSLP at Tahiti preceding El Ninos (1880-81, 1887-88, 1902-03, 1929-30, 1939-40, & 1968-69) that are defined using NOAA's new ERSSTv5 dataset that will very soon replace ERSSTv4 which the CPC currently uses to denote ENSO events after 1950.

ftp://ftp.bom.gov.au/anon/home/ncc/www/sco/soi/tahitimslp.html

1880 1015.3
1887 1015.2
1902 1015.1
1929 1015.1
1939 1015.1
1968 1014.8
 
Webberweather53 said:
Using CRU BOM Tahiti MSLP, I actually found 6 Julys with as high or higher MSLP at Tahiti preceding El Ninos (1880-81, 1887-88, 1902-03, 1929-30, 1939-40, & 1968-69) that are defined using NOAA's new ERSSTv5 dataset that will very soon replace ERSSTv4 which the CPC currently uses to denote ENSO events after 1950.

ftp://ftp.bom.gov.au/anon/home/ncc/www/sco/soi/tahitimslp.html

1880 1015.3
1887 1015.2
1902 1015.1
1929 1015.1
1939 1015.1
1968 1014.8
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Interesting. I've been using this table, which only goes back to 1950: http://www.cpc.ncep.noaa.gov/data/indices/tahiti

So, the first five you listed were from years not covered by this table. The only one that is after 1950, 1968-9, was at 1014.7 in the table I used vs 1014.8 in your link's table. So, just about a match there.

I find it interesting that there were zero Julys at Tahiti at 1015+ for the 26 El Ninos during the 77 years since 1940, but five during the prior 60 years!
 
GaWx said:
Interesting. I've been using this table, which only goes back to 1950: http://www.cpc.ncep.noaa.gov/data/indices/tahiti

So, the first five you listed were from years not covered by this table. The only one that is after 1950, 1968-9, was at 1014.7 in the table I used vs 1014.8 in your link's table. So, just about a match there.

I find it interesting that there were zero Julys at Tahiti at 1015+ for the 26 El Ninos during the 77 years since 1940, but five during the prior 60 years!
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Yeah, some of that is probably due to observational errors, limited coverage and/or biases in the dataset used, another portion can potentially be attributed to the warming background climate, wherein there may be some non negligible alterations in the zonal SLP gradient across the equatorial Pacific that are somewhat coupled to changes in the underlying ocean surface, which has featured a disproportinate amount of warming in the west-central Pacific as compared with the cold tongue further east & heightened frequency of central Pacific El Nino events esp after 1976. Definitely an interesting question to resolve and provide relative ascription to the various phenomena affecting it!
 
Idk, usually weak nino/neutral winter tend to be cold and snowy for the southeast. Sometimes
 
accu35 said:
Idk, usually weak nino/neutral winter tend to be cold and snowy for the southeast. Sometimes
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Weak Ninos have been on average colder than warm neutral. One major exception was the very cold, wet, icy, and snowy 1935-6 that Eric mentioned.

By the way, Nino 3.4 cooled from +0.5 to +0.4 in today's weekly release.
 
GaWx said:
Weak Ninos have been on average colder than warm neutral. One major exception was the very cold, wet, icy, and snowy 1935-6 that Eric mentioned.

By the way, Nino 3.4 cooled from +0.5 to +0.4 in today's weekly release.
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If we are talking about winter, it is important to understand the phase of the PDO as well. Moderate Ninos coupled with a warm PDO phase favor cooler conditions, especially for those in the mountains. While not as common, a cool PDO phase and moderate Nino are noticeably warmer.
 
Looking at the 12Z model consensus, I still do not yet see a clear indication of anything resembling the sustained solid -SOI streak of June returning. This takes us well into the first week of August. That's even after taking into account that my model consensus based Tahiti SLP estimates have been coming in about 1 mb too high at Tahiti.
 
GaWx said:
Weak Ninos have been on average colder than warm neutral. One major exception was the very cold, wet, icy, and snowy 1935-6 that Eric mentioned.

By the way, Nino 3.4 cooled from +0.5 to +0.4 in today's weekly release.
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I would also throw 1979-80, & 2003-04 into the mix for cool & snowy winters, at least in the Carolinas, although nothing, regardless of ENSO, compares to the consistency and intensity of cold & snow/ice in the winter 1935-36 which of course was amazing every month of the winter...

Just a couple big dogs from those winters in 1979-80 & 2003-04

February 26-27 2004 NC Snowmap.gif


March 1-2 1980 NC Snowmap.gif

February 6-7 1980 NC Snowmap.png
 
The ECMWF ENS shows no let up in the easterly trade winds in the central Pacific as we begin to near the 2nd week of August... Whatever chance we had of seeing an El Nino this winter is starting to go down the toilet.
Screen Shot 2017-07-24 at 6.19.18 PM.png
 
I much rather take my chances at weak nino/neutral than a strong nino.
 
Webberweather53 said:
I would also throw 1979-80, & 2003-04 into the mix for cool & snowy winters, at least in the Carolinas, although nothing, regardless of ENSO, compares to the consistency and intensity of cold & snow/ice in the winter 1935-36 which of course was amazing every month of the winter...

Just a couple big dogs from those winters in 1979-80 & 2003-04

View attachment 732


View attachment 733

View attachment 734
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Ahhh March 1-2, 1980 my all time favorite winter storm, not sure I'll ever see anything like that in my lifetime again. Wish my kids could see something like that just once.... that was freaking awesome!
 
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