bluewave

I am not ignoring anything. But thank you for giving the opportunity to clarify a few points. The -PNA -NAO from January into February 2021 followed the strong +PNA earlier that winter. The south based block in December 2020 was mitigated to an extent by the +PNA. But the height rises east of New England forced the storm formation further west giving BGM the record 40” jackpot instead of closer to the coast. It also resulted in the flood cutter on Christmas. So when the PNA shifted later on, the weak +PNA trough which was over the SE in December moved into the 50/50 slot. So there was definitely a +PNA assist from earlier in the season for that -PNA -AO pattern. Two very strong south based blocks in December 2020 and 2022. Not to mention the other record south based blocks during different months of the year. The PNA trough was weaker in January as a result.

Of course there are going to be variations. But the very nature of the variations can also change as the climate warms. Natural internal variability doesn’t exist in a vacuum.The -PNA -NAO patterns of the old days were colder and snowier in the Northeast than last winter. The -PNA trough last winter was weaker than was typical in the 50s to early 70s. So the issue last winter was the Greenland block building too far south in December. Those height rises east of New England were absent in the older era which I showed earlier in this thread under -PNA -NAO patterns. So expanding the ridges associated with blocks alters the storm track enough to make a big difference in the Northeast. All it takes in our area is a 50 to 200 mile shift in the storm track. That may not be a big deal on a continental to hemispheric teleconnection map .But it’s everything if the storm tracks west of NYC instead of out near the benchmark for people in our area.

Variations whether you call them cyclical, teleconnections, or oscillations all exist in a warmer climate state than they used to. So they aren’t immune from alterations or adjustments to reflect the warmer world. You are the one using terms like infantile and BS so maybe you are emotionally attached to colder winters from the past. That’s OK as long as you don’t let it influence your forecasting. I have offered many ideas about seasonal forecasts in too many threads to count. Just because I don’t offer a formal forecast each year isn’t a big deal. But I have successfully identified winter features in the fall that have worked out.

Off course you call BS since you look for a myriad of excuses to explain your way out of why the seasonal forecasts since 15-16 have all been biased too cold in the Northeast. Not sure why acknowledging that we have shifted into a warmer climate state is so hard for you. Again, this doesn’t mean that we won’t have colder winters at times again in the future. But even the colder run of winters at times from time to time from 02-03 to 14-15 were no match for the winters which were really cold from the late 70s to early 90s. Now if you want to ascribe it to some underlying cycle, the cycle was much colder in the late 70s to early 90s than 02-03 to 14-15. Plus the warming cycle since 15-16 was warmer than any earlier warmer periods by a large degree. So if we eventually swing back to another era like 02-03 to 14-15 in regard to colder winters making a comeback, chances are they won’t be as cold as some of those winters were. Our coldest Northeast winters since 02-03 were no match for the cold experienced from the late 70s to early 90s. 76-77…..18.4….5th coldest average winter temperature 77-78…..19.5 ..10th coldest 93-94….19.7…..11th coldest 78-79….20.7….18th coldest 14-15….20.8….19th coldest 02-03…20.9…20th coldest 13-14….22.1…..29th coldest.

The NE being the warmest part of the country over the last several years has plenty to do with the warming climate. Recent studies found as the WPAC heats up due to continued warming, we get more frequent MJO 4-6 phases which pumps the SE Ridge. Also slowing AMOC linked to warming climate causes warmer waters to pile up in the NW Atlantic. So it shifts the odds to warmer teleconnection patterns for us. Now this doesn’t mean that we won’t see another cold winter in the future. Or that we won’t see a shift to some new MJO state as the planet warms. But there is little doubt that the last 8 record warm seasons has had a robust warming climate signal.

More than some is due to warming. Any cold regressions in the future will be tempered by the warmer background state. But we should eventually see another colder winter again. Absent some massive volcanic eruption, a top 10 coldest winter like 76-77 simply isn’t possible anymore in this climate.

The one common denominator to all the winters since 15-16 has been the warmth in the Northeast. We have never seen an 8 winter stretch this warm before. But at least we have had some really good snowfall outcomes. 17-18 was trying to break the trend before the historic 80° warmth arrived in February around NYC. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/regional/time-series/101/tavg/3/2/1895-2023?base_prd=true&begbaseyear=1901&endbaseyear=2000 Warmest winter Northeast average temperature rankings since 15-16 30.7….2nd warmest temperature…..22-23….15-16 29.5….5th warmest temperature……16-17 28.9….6th warmest temperature…..19-20 27.1…..13th warmest temperature….20-21 26.1…..20th warmest temperature….21-22 25.6….23rd warmest temperature….18-19 25.3….26th warmest temperature…..17-18

Even with the closer to average last week against the warmer climate normals, the first 3 weeks of September have still finished top 5 warmest with widespread +3 to +5 departures. https://www.nrcc.cornell.edu/wxstation/perspectives/perspectives.html

The record breaking Hudson Bay block will really slow this down.

This is only the 6th time during a developing El Niño that the ACE went over a 100. It goes to the point of a weak MEI during those seasons. This summer matched a warmed up version the weak MEI composite. It was the first summer with ACE above 100 and Nino 3.4 going over +1.5. The same goes for the hurricane forecasts which beat model expectations of a quiet season. So another indicator of how valuable using MEI can be for seasonal forecasting. It also highlights the limited role of looking at isolated metrics like Nino 3.4 in evaluating the impact of El Niño.This played out last winter with the much lower MEI than 3.4 indicated. Some people automatically assume that somehow a weak MEI guarantees a cold winter. But we have seen every time since 15-16 how regardless of MEI or ENSO, the winter has been warm. So winter temperatures have mostly been a function of our warmer climate. But we’ll eventually get a colder winter if the area west of the Dateline can go bonkers like we saw in 13-14 and 14-15. It’s just very difficult to forecast with any degree of certainty when this will happen again. Previous El Niño ACE seasons over 100 none were strong 2023…116…weak MEI so far 2018….132…El Nino couldn’t couple so the SE Ridge made an appearance due to too much MJO 4-6 forcing 2004….226…weak MEI throughout the event 1969…165……weak MEI 1963…117…….don’t have MEI value but El Niño was moderate 1951….126…don’t have MEI weak El Niño to neutral winter

The forcing is further west like the weaker or Modoki events for the month of September than the stronger ones. But the lack of VP anomalies extending north of the equator is very unusual along with the -SOI not producing any appreciable WWBs. So not really like strong or Modoki events in that regard. So this is another conformation of how weak the MEI has been. Not sure what impact a continuation of these weaker VP anomalies north of the equator may have beyond mentioning possible weak coupling like the MEI suggests.

This is the 1st time that Nino 4 made it to nearly +30 C during the month of September since 2015. The 1.2, 3, and 3.4 regions have all been higher during this time of year. So as long as Nino 4 remains this warm relative to the other regions, the forcing will continue to lean west. +30C SSTs are essentially a forcing magnet.

The stronger trades not letting 3.4 get much higher than the 1.6 peak around a month ago. I think the weaker EQSOI isn’t letting the SOI couple preventing the stronger WWBs we would usually get.

The cooler mornings over the last week feel pretty good compared to how warm the month started out. Even the UHI areas have had min departures in line with more rural areas. Data for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Date Min Temperature Min Temperature Departure 2023-09-15 58 -6.8 2023-09-16 62 -2.5 2023-09-17 62 -2.1 2023-09-18 64 0.2 2023-09-19 61 -2.4 2023-09-20 61 -2.1 Data for New Brunswick Area, NJ (ThreadEx) Click column heading to sort ascending, click again to sort descending. Date Min Temperature Min Temperature Departure 2023-09-15 55 -2.0 2023-09-16 54 -2.6 2023-09-17 49 -7.2 2023-09-18 56 0.2 2023-09-19 54 -1.4 2023-09-20 51 -4.0 2023-09-21 50 -4.5 Data for POCONO MOUNTAINS MUNICIPAL AIRPORT, PA Click column heading to sort ascending, click again to sort descending. Date Min Temperature Min Temperature Departure 2023-09-15 47 -3.0 2023-09-16 45 -4.7 2023-09-17 45 -4.3 2023-09-18 51 2.0 2023-09-19 43 -5.6 2023-09-20 41 -7.3 Data for DANBURY MUNICIPAL AP, CT Click column heading to sort ascending, click again to sort descending. Date Min Temperature Min Temperature Departure 2023-09-15 51 -1.7 2023-09-16 50 -2.3 2023-09-17 46 -6.0 2023-09-18 60 8.4 2023-09-19 51 -0.2 2023-09-20 46 -4.9

I think I can remember an AFD out of Mount Holly mentioning they had been evaluating which models were scoring best with storm tracks one winter in the last 5 years or so?

The departures and warmth rankings at Newark are identical to the rest of the region so no cherry pick involved. I only do that in deference to the large contingent of our posters that live in NJ. So yes the absolutes are usually higher in NJ. But warmth rankings are the same around the whole region. The first two weeks of September were near the warmest on record around the entire upper MA to NE region. https://www.nrcc.cornell.edu/wxstation/perspectives/perspectives.html

It’s the first time since 1983 with the warmest annual temperature occurring in September without tying with an earlier month. Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season 2023 93 90 91 96 91 97 M 97 2022 88 98 96 102 101 93 76 102 2021 89 96 103 97 99 91 84 103 2020 69 86 93 96 94 89 79 96 2019 80 90 93 99 94 93 96 99 2018 84 94 96 98 96 98 82 98 2017 87 94 99 98 93 92 86 99 2016 83 96 91 99 98 94 87 99 2015 82 91 93 98 97 98 81 98 2014 83 88 92 96 93 95 79 96 2013 85 94 96 101 91 96 89 101 2012 88 92 99 104 95 92 81 104 2011 87 92 102 108 98 88 88 108 2010 92 95 98 103 98 98 79 103 2009 93 87 89 91 95 86 77 95 2008 82 87 99 98 91 92 79 99 2007 86 94 96 97 95 92 89 97 2006 83 94 95 98 101 85 82 101 2005 88 84 97 101 102 94 81 102 2004 88 92 97 91 92 87 76 97 2003 88 81 95 95 93 82 78 95 2002 97 90 96 100 100 91 86 100 2001 87 94 95 97 105 88 83 105 2000 78 94 96 93 92 88 82 96 1999 83 90 99 103 99 88 76 103 1998 74 90 94 98 93 92 79 98 1997 74 86 97 101 97 86 88 101 1996 88 99 92 91 92 92 78 99 1995 82 90 97 104 98 91 85 104 1994 92 95 102 99 95 92 78 102 1993 82 93 102 105 100 100 82 105 1992 79 98 90 97 95 90 83 98 1991 88 93 97 102 96 95 82 102 1990 94 83 92 98 93 91 88 98 1989 79 89 96 99 97 97 80 99 1988 74 94 101 101 99 86 81 101 1987 79 98 96 97 97 87 75 98 1986 80 95 94 100 90 89 85 100 1985 89 92 89 94 97 94 80 97 1984 77 89 97 95 93 88 82 97 1983 85 84 96 98 97 99 84 99

The 2nd week of the month was still pretty warm. But in our new warmer climate wasn’t as extreme as week 1. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Avg Temperature Departure 2023-09-01 79 60 -4.3 2023-09-02 83 59 -2.6 2023-09-03 92 66 5.7 2023-09-04 93 72 9.4 2023-09-05 95 78 13.7 2023-09-06 97 77 14.5 2023-09-07 96 76 13.8 2023-09-08 92 73 10.5 2023-09-09 88 73 8.9 2023-09-10 81 70 4.2 2023-09-11 85 72 7.5 2023-09-12 87 69 7.3 2023-09-13 83 71 6.7 2023-09-14 81 63 2.0 2023-09-15 74 58 -3.6 2023-09-16 79 60 0.2 2023-09-17 79 56 -1.4 2023-09-18 70 62 -2.5 2023-09-19 77 59 -0.1 2023-09-20 78 58 0.3

The first two weeks of the month were endless summer as they they were one of the warmest on record. Since the 15th we have been pretty close to average against the warmer 91-20 climate normals. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Sep 1 to Sep 14 Missing Count 1 1961-09-14 81.4 0 2 2023-09-14 79.0 0 3 1983-09-14 77.2 0 4 2015-09-14 76.9 0 5 1947-09-14 76.4 0 Time Series Summary for WESTCHESTER CO AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Sep 1 to Sep 14 Missing Count 1 1961-09-14 77.8 0 2 1983-09-14 74.6 0 3 2023-09-14 74.5 0 4 2015-09-14 73.7 0 5 2016-09-14 72.9 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Sep 1 to Sep 14 Missing Count 1 2023-09-14 75.9 0 2 1983-09-14 74.1 0 3 2015-09-14 73.9 0 4 1980-09-14 73.1 0 5 2016-09-14 72.7 0

Sure. The PDO is essentially an Aleutian low index. +PDO has a giant cold pool and low pressure north of a Hawaii. Strong ridge and warmer waters underneath in -PDO. Read studies that the PDO and Aleutian low are regulated through SST changes in the WPAC. But sometimes the PDO isn’t very well coupled to the actual pattern like in 20-21 and Jan 22. So sometimes just using a persistence forecast based on the PDO SST signature doesn’t work. Plus now we have these non-canonical expressions with distortions to the original composites.

I also ready a study that the persistent +AO +NAO during those years was related to the IO forcing near India.

I know you have been a supporter of having the CMC on your side when making a forecast. I would have to say the model is the most Improved since recent upgrades. I wish we had a east coast storm statistical storm tracker which would score the models solely on forecasting the most accurate track. These Northern Hemispheric skill scores don’t tell us much about which model get our storm tracks right. But the skill on a hemispheric scale is great for temperature and teleconnection forecasts.

Models starting to converge on the wetter coastal hugger tucked in track. The CMC came east and the Euro west. So a compromise of about 65% of what CMC had and about 35% Euro. So two swings and a miss so far from the Euro with tropical tracks.

While the Euro has been running warm, it has Nino 4 as the warmest region near +30C during the winter. That would tilt the forcing further west and negate 1+2. Remember, we have not seen any 1+2 forcing due to the balance of the warmest waters being near 4. Much different from true based east events which weren’t near +30C in Nino 4 allowing 1+2 and 3 to dominate. I think the Euro is overdone since it’s now warmer in 4 than 09-10 and 15-16.

The super Modoki +PNA -AO was fine in January and February. But we had to reverse the MJO 4-6 super Nina-like Maritime Continent +13 December forcing. This provided probably the most extreme winter month to month variation since December 89 and January 90. But 15-16 was much more satisfying for the historic snowfall fans around NYC.