Terpeast Posted October 17, 2023 Share Posted October 17, 2023 22 minutes ago, bluewave said: These PDO fluctuations between -0.5 and -2.5 have been the norm this year. Notice the big up and down pattern since January. So we want to see some actual positives sustain to get a sense that the PDO is shifting. A cold pool would need to develop north and northwest of Hawaii for a true +PDO. This would be indicative of a more Nino-like Aleutian Low. But continued ridging near the Aleutians even if the PDO becomes more neutral is still problematic since it promotes a Western Trough and SE Ridge. I think that’s where you and I differ a bit. I don’t think the PDO has to flip positive for the MA/SNE to get a decently productive winter. A +PDO, especially if strong, also brings its own set of challenges, like a too-strong aleutian low flooding the CONUS with mild air a la 97-98. It’s a double edged sword, and as the 1960s and 09-10 has proved, we don’t need the PDO to flip in a dramatic manner, just move towards the neutral range. 1 1 Link to comment Share on other sites More sharing options...
qg_omega Posted October 17, 2023 Share Posted October 17, 2023 9 hours ago, so_whats_happening said: This should help with getting a more consistent look of an Aleutian low while waters off Japan are still cooling they are cooling much less than it has been, long ways to go it seems for destroying the -PDO but we should see a nice tick down for the monthly number. Classic east based Nino 4 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 30 minutes ago, Terpeast said: I think that’s where you and I differ a bit. I don’t think the PDO has to flip positive for the MA/SNE to get a decently productive winter. A +PDO also brings its own set of challenges, like a too-strong aleutian low flooding the CONUS with mild air. It’s a double edged sword, and as the 1960s and 09-10 has proved, we don’t need the PDO to flip, just move towards neutral. I only use the PDO in reference to what is happening north and northwest of Hawaii. The absolute PDO values are only relevant when it’s well coupled with the 500 mb pattern. I like Simon Lee’s 500 mb classification pattern since it emphasizes the more important 500 mb patterns. The Pacific ridge pattern is classic -PDO. And the Alaskan Ridge is closer to +PDO. It really simplifies things. The Alaskan ridge pattern drove the record +PDO in 14-15. But most winters since then have been the Pacific ridge. My guess is that the PDO is being driven more by what is happening in the WPAC tropics and subtropics. So the actual SSTs may only be secondary to the 500 mb patterns. But extended coupled phases probably reinforce each other. 3 Link to comment Share on other sites More sharing options...
Terpeast Posted October 17, 2023 Share Posted October 17, 2023 10 minutes ago, bluewave said: I only use the PDO in reference to what is happening north and northwest of Hawaii. The absolute PDO values are only relevant when it’s well coupled with the 500 mb pattern. I like Simon Lee’s 500 mb classification pattern since it emphasizes the more important 500 mb patterns. The Pacific ridge pattern is classic -PDO. And the Alaskan Ridge is closer to +PDO. It really simplifies things. The Alaskan ridge pattern drove the record +PDO in 14-15. But most winters since then have been the Pacific ridge. My guess is that the PDO is being driven more by what is happening in the WPAC tropics and subtropics. So the actual SSTs may only be secondary to the 500 mb patterns. But extended coupled phases probably reinforce each other. Yeah I’ve seen this before, and it’s a great reference to simplify things. But I’m taking a broader Pacific-wide view of the PDO, not only the basin north/NW of Hawaii. I also look at the pdo cycle 1-3 years before each preceding winter analog season to get an idea of how conditions evolved up to each winter. The part you and I agree on is that there will be competing factors this winter, with the -pdo working against us. But I believe the “negativity” of the pdo will weaken, and the basin-wide (or west-leaning) enso will eventually win out. meanwhile, of course we are going to see -pna episodes that’s going to get people here concerned (while its of no surprise to me). 2 Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted October 17, 2023 Share Posted October 17, 2023 7 minutes ago, Terpeast said: Yeah I’ve seen this before, and it’s a great reference to simplify things. But I’m taking a broader Pacific-wide view of the PDO, not only the basin north/NW of Hawaii. I also look at the pdo cycle 1-3 years before each preceding winter analog season to get an idea of how conditions evolved up to each winter. The part you and I agree on is that there will be competing factors this winter, with the -pdo working against us. But I believe the “negativity” of the pdo will weaken, and the basin-wide (or west-leaning) enso will eventually win out. meanwhile, of course we are going to see -pna episodes that’s going to get people here concerned (while its of no surprise to me). I think the main limitation of that is reducing the likelihood of an extremely cold winter. 1 Link to comment Share on other sites More sharing options...
Terpeast Posted October 17, 2023 Share Posted October 17, 2023 9 minutes ago, 40/70 Benchmark said: I think the main limitation of that is reducing the likelihood of an extremely cold winter. Yeah, agreed. That’s the direction I’m leaning towards atm 2 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 48 minutes ago, 40/70 Benchmark said: I think the main limitation of that is reducing the likelihood of an extremely cold winter. It goes beyond the ENSO to the multi-winter warm pattern since 15-16. We will eventually see another cold winter in the Northeast. But I am not even sure what type of indication we would get before the season to make that call in October or November. The warmth has become so persistent that it’s uncertain what would be required to shift that pattern colder. 3 Link to comment Share on other sites More sharing options...
40/70 Benchmark Posted October 17, 2023 Share Posted October 17, 2023 Just now, bluewave said: It goes beyond the ENSO to the multi-winter warm pattern since 15-16. While we will eventually see another cold winter in the Northeast, I am not even sure what type of indication we would get before the season to make that call in October or even November. Yea, multidecadal PAC cold phase signal...no doubt. Any speculation beyond that is for the CC forum. 2 Link to comment Share on other sites More sharing options...
jm1220 Posted October 17, 2023 Share Posted October 17, 2023 13 minutes ago, bluewave said: It goes beyond the ENSO to the multi-winter warm pattern since 15-16. We will eventually see another cold winter in the Northeast. But I am not even sure what type of indication we would get before the season to make that call in October or November. The warmth has become so persistent that it’s uncertain what would be required to shift that pattern colder. I guess one positive is that the W PAC isn’t boiling hot anymore so the MJO should be more favorable, but the warm water NW of Hawaii of course is another turd in the punch bowl. The waters off the SE US aren’t too warm so we shouldn’t see a raging SE ridge again, which is also a Nina not Nino trait, but like others said it’s hard to determine if the pattern drives the SSTA’s or the other way around. 1 Link to comment Share on other sites More sharing options...
GaWx Posted October 17, 2023 Share Posted October 17, 2023 1 hour ago, Terpeast said: meanwhile, of course we are going to see -pna episodes that’s going to get people here concerned (while its of no surprise to me). Whether we’d get it or not, we’d be overdue for a -PNA or at least neutral PNA month in Nov. June-Sep were all +PNA months. Also, there’s a near certainty for Oct to do the same. There have been only 3 other years since 1950 with all of June-Oct having a +PNA (all +0.45+ in the current case). I don’t count 1960 and 1964 because they had lowest PNA months of +0.04/+0.15 within June-Oct, which I consider neutral. 1 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 35 minutes ago, jm1220 said: I guess one positive is that the W PAC isn’t boiling hot anymore so the MJO should be more favorable, but the warm water NW of Hawaii of course is another turd in the punch bowl. The waters off the SE US aren’t too warm so we shouldn’t see a raging SE ridge again, which is also a Nina not Nino trait, but like others said it’s hard to determine if the pattern drives the SSTA’s or the other way around. One of these winters we may just have to rely on the new warmer 91-20 climate normals. The warmer winter averages could help with a winter that gets close but would have been warm under 81-10 normals. This is how we got a cooler summer in the Northeast this year. The new warmer 91-20 climate normals allowed the Northeast to finish the summer at -0.2. But under the cooler 81-10 climate normals it would have been +0.4. 1 Link to comment Share on other sites More sharing options...
griteater Posted October 17, 2023 Share Posted October 17, 2023 From NOAA CPC Weekly MJO Update: 1 2 Link to comment Share on other sites More sharing options...
griteater Posted October 17, 2023 Share Posted October 17, 2023 Here is the Oct JMA VP forecast for Dec-Feb. Max uplift along and just west of the Dateline (West El Nino forcing) and in E Africa (+IOD). Solid subsidence in E Indian Ocean and Indonesia. Maybe we finally get the MJO to be quiet in phases 3/4/5 this winter. JMA 500mb forecast for Dec-Feb: JMA 500mb forecast last October for Dec-Feb 2022-2023. It's pretty much the exact opposite of this year's forecast... JMA forecast from Oct last year did quite well, though not perfect. Has the general ridge / trough pattern correct from E Asia thru N America, also with above normal heights in the N Atl. It was off with the severity / location of the below normal heights in E Asia & W North America Finally, here is the JMA forecast for Dec-Feb SSTs. Basin Wide El Nino (SSTs) with solid cool zone in E Indian Ocean thru the Maritime Continent 6 2 Link to comment Share on other sites More sharing options...
brooklynwx99 Posted October 17, 2023 Share Posted October 17, 2023 4 minutes ago, griteater said: Here is the Oct JMA VP forecast for Dec-Feb. Max uplift along and just west of the Dateline (West El Nino forcing) and in E Africa (+IOD). Solid subsidence in E Indian Ocean and Indonesia. Maybe we finally get the MJO to be quiet in phases 3/4/5 this winter. JMA 500mb forecast for Dec-Feb: JMA 500mb forecast last October for Dec-Feb 2022-2023. It's pretty much the exact opposite of this year's forecast... JMA forecast from Oct last year did quite well, though not perfect. Has the general ridge/trough pattern correct from E Asia to N America, also with above normal heights in the N Atl. It was off with the severity / location of the below normal heights in E Asia & W North America Finally, here is the JMA forecast for Dec-Feb SSTs. Basin Wide El Nino (SSTs) with solid cool zone in E Indian Ocean thru the Maritime Continent it's interesting that even though this is a pretty typical EP Nino in terms of SSTs from like 120W eastward, it seems like the forcing the models are spitting out still resembles those of Modoki winters. it seems like the farther west forcing has some credence, as it's hung back farther west thus far this month it also seems like there is a good bit of misunderstanding that I've seen both here and on Twitter... this is a typical EP Nino in terms of SSTs. however, given how warm the WPAC is, it seems like this event is less coupled with the forcing ending up farther west, leading to bouts of Modoki forcing at times even with a basin-wide SST signature. not sure why it has to be all-or-nothing. nuance exists, and it seems like modeling is picking up on something that says that this won't act like a typical high-end EP event 7 Link to comment Share on other sites More sharing options...
griteater Posted October 17, 2023 Share Posted October 17, 2023 Sep-Oct VP for all years with El Nino and noteworthy +IOD since 1980: Same, but removing the Super El Nino years - same placement, but with less intensity: Here is this year for the 2-month period of Aug 15 to Oct 15. It's different from the above composites so far (bumped west)... 1 2 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 1 hour ago, griteater said: Here is the Oct JMA VP forecast for Dec-Feb. Max uplift along and just west of the Dateline (West El Nino forcing) and in E Africa (+IOD). Solid subsidence in E Indian Ocean and Indonesia. Maybe we finally get the MJO to be quiet in phases 3/4/5 this winter. It’s a significantly warmer winter temperature version of the 02-03, 09-10, and 14-15, Modoki El Niño forcing west of the Dateline. Even though the PDO is neutral to negative with warmth north of Hawaii, it doesn’t look like the PDO is coupled enough to drive the bus. That strong -EPO +PNA is more +PDO-like. It’s also giving a solid -AO signature. The winter temperatures aren’t nearly as cold as the composite but I am sure that 500 mb look would be better than the last few winters for snowfall. The only colder areas are south of 40N along the East Coast. 1 2 Link to comment Share on other sites More sharing options...
GaWx Posted October 17, 2023 Share Posted October 17, 2023 1 hour ago, griteater said: Here is the Oct JMA VP forecast for Dec-Feb. Max uplift along and just west of the Dateline (West El Nino forcing) and in E Africa (+IOD). Solid subsidence in E Indian Ocean and Indonesia. Maybe we finally get the MJO to be quiet in phases 3/4/5 this winter. Not only that, but I think we have a good shot at 1-2 months of DJF with an overall weak MJO (including many days inside the COD) hopefully with a lean toward the left side for the upcoming DJF. I say that because of the weak MJO so far this month (see below) along with the expectation based on model consensus that Oct 2023 as a whole will come in weak. Looking back at the 16 prior El Niños back to 1976-7, I found these 6 (38% of them) with weak MJO Octobers: 1977, 1982, 1987, 1997, 2002, and 2014. Here’s the subsequent MJO amp for DJF for these 6 weak Oct MJO cases: -D was weak 3 times, moderate twice, and strong once. -J was also weak 3 times, moderate twice, and strong once. -F was weak 3 times, moderate once, and strong twice. Now I’ll look at moderate Oct MJOs during El Niño: 1976, 1986, 1991, 1994, 2004, 2009, 2015, 2018. -D weak once (2004), moderate 5 times, strong twice -J also weak once (1977), moderate 5 times, strong twice -F also weak once (1977), moderate 5 times, strong twice So when comparing weak Oct MJO to moderate Oct MJO during El Nino, the moderate Oct tend to keep it mainly moderate in winter vs being weak more often than moderate during winter following a weak Oct MJO. So, it appears that during El Niño there’s some correlation of Oct MJO amplitude and the subsequent winter MJO amplitude based on weak vs moderate Oct stats. This image shows how weak the MJO has been this month so far: 1 2 Link to comment Share on other sites More sharing options...
Daniel Boone Posted October 17, 2023 Share Posted October 17, 2023 26 minutes ago, bluewave said: It’s a significantly warmer winter temperature version of the 02-03, 09-10, and 14-15, Modoki El Niño’s. Notice the forcing west of the Dateline. Even though the PDO is neutral to negative with warmth north of Hawaii, it doesn’t look like the PDO is coupled enough to drive the bus. That strong -EPO is more +PDO-like. It’s also giving a solid -AO signature. The winter temperatures aren’t nearly as cold as the composite but I am sure that 500 mb look would be better than the last few winters for snowfall. The only colder areas are south of 40N along the East Coast. If that is indeed the Case for this Winter, you've hit on the probable Reason.. at least from what we can logically see. Formidable upstream blocking will still mitigate the -PDO effects if it does rear up, providing HLB is present. Link to comment Share on other sites More sharing options...
snowman19 Posted October 17, 2023 Share Posted October 17, 2023 There is no Nino coupling. That is a full fledged Nina look on the ensembles for late October with big -PNA Please stop. Absolutely horrible analysis and bad, bad info. If you are going to post nonsense like this just don’t post. This Nino is in fact very well coupled, SOI, STJ response, SSTs, WWB, Nino standing wave/convection, etc. This is a typical MJO phase 8 response for this time of the year with +ENSO, +GLAAM. Phase 8 isn’t cold this time of the year with a Nino in place. Look at the MJO composite! 2 Link to comment Share on other sites More sharing options...
GaWx Posted October 17, 2023 Share Posted October 17, 2023 1. As mentioned before, there’s little correlation of both summer and Oct NAO to winter NAO. So, this means that having a strong -NAO this past summer and having one this month don’t, when looked at alone, increase the chance for a -NAO this winter. Based on progs, the Oct NAO has a very good shot to be within -1.6 to -2.1 (top 10 -NAO Oct since 1950) and may end up as the 5th lowest Oct NAO since 1950 (93 percentile). 1960, 1968, 1980, 1992, 1997, 2002, 2006, 2012, and 2021 had the 9 lowest Oct NAOs. How was the subsequent DJF NAO for these 9? 1960: +0.31 1968: -1.26 1980: +0.69 1992: +0.86 1997: -0.23 2002: -0.05 2006: +0.36 2012: +0.02 2021: +1.02 So, of these 9, only one (1968) had a -NAO winter to follow though it was strong. Three were neutral and five had a +NAO. 2. Whereas I found no correlation of Oct -NAO to winter -NAO, I do see what appears to be a pretty good correlation of a sub -0.75 Nov NAO to Dec -NAO. For the sub -0.75 Novembers, here were the Dec NAOs: 1950 -1.02 1952 -0.43 1955 +0.17 1963 -1.92 1965 +1.37 1968 -1.40 1969 -0.28 1973 +0.32 1983 +0.29 1995 -1.67 1997 -0.96 2000 -0.58 2010 -1.85 So, following a sub -0.75 Nov NAO, the following Decembers 9 of the 13 times had a -NAO, once had neutral, and three times had a +NAO. Out of the 13, five had a strong -NAO vs only one with a strong +NAO. Four out of the 5 El Niño cases had a -NAO Dec. So, what this is telling me is that if we can get a sub -0.75 next month, I’d actually feel good about the chance for a -NAO in Dec. So, I’ll soon start following the models for Nov NAO hints. Keep in mind though that only two of the nine lowest Oct NAOs were followed by a sub -0.75 Nov. due to no more than a small correlation. 2 Link to comment Share on other sites More sharing options...
Typhoon Tip Posted October 17, 2023 Share Posted October 17, 2023 6 hours ago, 40/70 Benchmark said: I think the main limitation of that is reducing the likelihood of an extremely cold winter. Lol... add that to the list, huh - Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 3 hours ago, Daniel Boone said: If that is indeed the Case for this Winter, you've hit on the probable Reason.. at least from what we can logically see. Formidable upstream blocking will still mitigate the -PDO effects if it does rear up, providing HLB is present. Yeah, we would want to see the PDO remain uncoupled if it does stay negative. While the JMA has done OK with recent La Niña winters, it didn’t do very well with the El Niño in 18-19 that couldn’t couple. So it put all its eggs in the Modoki basket which didn’t verify. The well coupled -PDO wound up running the table instead. 1 1 Link to comment Share on other sites More sharing options...
brooklynwx99 Posted October 17, 2023 Share Posted October 17, 2023 1 minute ago, bluewave said: Yeah, we would want to see the PDO remain uncoupled if it does stay negative. While the JMA has done OK with recent La Niña winters, it didn’t do very well with the El Niño in 18-19 that couldn’t couple. So it put all its eggs in the Modoki basket which didn’t verify. The well coupled -PDO wound up running the table instead. I don't think we're going to deal with a lack of coupling here... the forcing is already much stronger than it was in 2018. 2018 isn't like this year whatsoever in terms of tropical forcing. this year is more like 2002 and 2009 so far 1 Link to comment Share on other sites More sharing options...
Terpeast Posted October 17, 2023 Share Posted October 17, 2023 7 minutes ago, brooklynwx99 said: I don't think we're going to deal with a lack of coupling here... the forcing is already much stronger than it was in 2018. 2018 isn't like this year whatsoever in terms of tropical forcing. this year is more like 2002 and 2009 so far Regarding comparison to 18-19, @brooklynwx99 just presented an open-and-shut case here. Previously, I had 18-19 as one potential analog, but not anymore. 1 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 10 minutes ago, brooklynwx99 said: I don't think we're going to deal with a lack of coupling here... the forcing is already much stronger than it was in 2018. 2018 isn't like this year whatsoever in terms of tropical forcing. this year is more like 2002 and 2009 so far Better El Niño forcing yes, but we need to lose the coupled -PDO so we don’t end up with a trough near the West caped by a +PNA ridge in Canada. That would drive the downstream ridge over the Northeast which we don’t want. It was what the Euro seasonal was showing. Plus my comment was more to how well the model did with the last non-La Niña winter. Not that this was a copy so far of that year. Outside the Pacific, we have had very impressive blocking on the Atlantic side since June. 1 Link to comment Share on other sites More sharing options...
brooklynwx99 Posted October 17, 2023 Share Posted October 17, 2023 Just now, bluewave said: Better El Niño forcing yes, but we need to lose the coupled -PDO so we don’t end up with a trough near the West caped by a +PNA ridge in Canada. That would drive the downstream ridge over the Northeast which we don’t want. Plus my comment was more to how well the model did with the last non-La Niña winter. Outside the Pacific, we have had very impressive blocking on the Atlantic side since June. I would imagine that since this year will have much more impressive tropical forcing, it should be able to pick up on the pattern better. but yes, seasonal models aren't the best. the November runs really should be quite good, though. tough to get a seasonal to totally flop that close in when the coupling is really beginning to kick in most of the time 1 Link to comment Share on other sites More sharing options...
Terpeast Posted October 17, 2023 Share Posted October 17, 2023 When do the November runs come out? Thinking of holding off on my winter outlook till then. Too many moving variables atm 1 Link to comment Share on other sites More sharing options...
bluewave Posted October 17, 2023 Share Posted October 17, 2023 5 minutes ago, brooklynwx99 said: I would imagine that since this year will have much more impressive tropical forcing, it should be able to pick up on the pattern better. but yes, seasonal models aren't the best. the November runs really should be quite good, though. tough to get a seasonal to totally flop that close in when the coupling is really beginning to kick in most of the time We have seen very low skill forecasts issued in late November for December. The EPS weeklies completely missed how warm things got in December 2015 from the November 22nd forecast. So these weekly to monthly and seasonal outlooks can have significant errors. 2 Link to comment Share on other sites More sharing options...
GaWx Posted October 17, 2023 Share Posted October 17, 2023 3 hours ago, bluewave said: We have seen very low skill forecasts issued in late November for December. The EPS weeklies completely missed how warm things got in December 2015 from the November 22nd forecast. So these weekly to monthly and seasonal outlooks can have significant errors. Keeping in mind the high level of inaccuracy of the EPS weeklies, today’s version does have slightly higher H5 ht anomalies (slightly above normal) over Greenland and Iceland than to the south (near normal). Whereas the actual calculation of the NAO is based on SLP anomalies in Iceland and the Azores, H5 ht anomaly differences are often used to give a general idea due to a significant correlation. So, weeks 2-4 of Nov are leaning -NAO on this run after a neutralish week 1. 1 Link to comment Share on other sites More sharing options...
griteater Posted October 17, 2023 Share Posted October 17, 2023 49 minutes ago, Terpeast said: When do the November runs come out? Thinking of holding off on my winter outlook till then. Too many moving variables atm Here is your November Itinerary 10/31 (Aftn): CANSIPS Update on Twitter 10/31 (Evening): CANSIPS Update on Tropical Tidbits 11/3: Aug-Oct ENSO ONI & ENSO RONI Updates from NOAA 11/5: Update of Euro Seasonal Forecast 11/5: ENSO MEIv2 Update from NOAA 11/10: Update of Copernicus C3S Ensemble Seasonal (with this, can also view JMA / Meteo France / UKMet Office updates) 11/10 to 11/20: Update of JAMSTEC Seasonal 4 3 Link to comment Share on other sites More sharing options...
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