bluewave

Only to the extent that you can remain in the air conditioning and spend less time outside. Extreme heatwaves in the summer can be dangerous especially to the elderly.

The upper ocean heat content pattern along with the weaker WWBs never matched previous super El Niño years. So the more aggressive models were just showing excessive momentum.

The Euro October monthly forecast error continues to grow with the daily Nino 3.4 back down below +1.6.

I guess we are fortunate that the summer temperatures aren’t warming as quickly as the fall and winter. It’s easier to adapt to a warmer fall and winter than summer. So I think the average person likes the milder falls and winters. It’s part of the reason that most of the migration in this country is away from colder climates to warmer ones. Northeast temperature increases since 1981 per decade SEP…+1.0° per Decade OCT…+0.9 NOV…+0.2 DEC…+1.0 JAN…+1.2 FEB….+0.3 MAR…+0.4 APR….+0.3 MAY….+0.4 JUN….+0.3 JUL….+0.6 AUG….+0.6

Out of phase PDO since the spring with some of the weakest developing El Niño WWBs on record. To understand the diversity of the El Niño-Southern Oscillation (ENSO) under the background of Pacific decadal oscillation (PDO) during recent decades, characteristics of westerly wind bursts (WWBs) during positive and negative phases of the PDO were analyzed. It is shown that, during the ENSO developing period, the El Niño evolution may be affected by stronger or more frequent WWBs in the positive PDO phase than in the negative PDO phase. The sustained effects of atmospheric dynamics on the equatorial ocean can be indicated by the accumulated WWB strength, which contains most WWB characteristics, including the accumulated days, occurrence frequency, strength, and spatial range of WWBs. The synoptic/climate systems that are directly related to WWBs show a wider spatial distribution in the positive PDO phase than in the negative PDO phase. … … … …

Because the more extreme ones usually had a stronger 500 mb vortex near the Northeast than in recent years.

This far south blocking hasn’t happened before with the -AO magnitudes that I mentioned. But we did have much weaker -AOs in the past that did build this far south. While the blocking has been the strongest on record in Canada from May to October, it hasn’t allowed for much cooler air in North America. Like the 500mb heights expanding so much that there was no cool air available for the troughs. I am hoping that we can get some of these decent -AO +PNA intervals during the winter to give us a better snowfall outcome than last winter even if there isn’t much cold air available for the troughs to work with.

We were talking specifically about the Northeast so that’s why I zoomed in. Most people don’t realize how unusual last winter was. NYC had the lowest snowfall ever for any single winter month with an -AO reading lower than -2.5 by a wide margin. Plus it was the warmest winter out of the bunch by and equally wide margin. 1983 and 1996 were nowhere near as far south with the blocking as recent years. Sure we are dealing with small sample sizes since we are only several years into a new decade. But what we have been seeing with heights building into the Northeast is something new with -AO s of these magnitudes so far. Plus you agreed with me with your AMO composite so not sure what our differences are. NYC snowfall with monthly DJF -AO reading dipping below -2.5 and average temperature 22-23…2.3”….41.0° 10-11…61.9….32.8° 09-10…51.4….33.8° 84-85…24.1….36.4° 77-78….50.7….30.3° 76-77….24.5….28.4° 68-69…30.2….32.9° 65-66…21.4…..35.9° 62-63….16.3….29.9°

You said that not me. All I stated was that several models have high temperatures around 80° on the warmest days this week. Plus you have to remember long range official forecasts are more conservative since they don’t like to make big jumps from run to run. They like to be more gradual in increasing their high temperatures the closer we get. If there were any record lows in the 20s this week for around NYC I would be posting that also. So the echo chamber you mention is the actual pattern not that people are pointing it out.

I shifted the map closer to the Northeast so we could see the finer details. While the 2020s are still young, our strong -AO blocking Decembers of 2022 and 2020 were much further south than their counterparts from previous decades. December 2022 was the furthest south block on record with a monthly -AO value lower than-1.5 and -PNA for the month. Same goes for December 2020 which was furthest south based for a +PNA. We could expand to compare January 2021 which had an -AO block lower than -1.5 which was further south based than previous decades. We could also include other months of the year but not enough space in this post to compare. 2020s December -AO -PNA Earlier -AO -PNA December 2020 -AO +PNA Earlier -AO +PNA

I think part of the issue we see on wx twitter is the tendency for people to give long range ENSO models the same weight as a short term model forecast. I have been pointing out since last spring the warm bias these ENSO forecasts have been exhibiting for years. It’s OK to question a models output which makes for a much better forecast. Plus this warm bias has become more evident in the recent era of the seemingly perma-Niña background state.

The bottom line is that 70° Septembers and 60° Octobers have become more common. Same goes for 50° Novembers and 40° Decembers. In the old days we had the coldest Septembers which were closer to 60° and Octobers which were near 50°. The most extreme version of this was the 50° December 2015 which would still rank near the warmest on record for November. So our monthly temperatures continue to shift closer to places like Norfolk and DC. The good news for us is that we can adapt to a climate closer to Virginia.

So why are you ignoring the posts from the CPC stating that there is only a 30% chance of a super El Niño due to the much lower upper ocean heat anomalies?

It’s all about proportionality. Sure it feels chilly out there this morning. But the cold is nowhere near a record. Highs in the low 80s later this week is near the record. We would need lows in the 20s to set a record. That’s what people are saying. Several of our recent winters since 15-16 were near the warmest on record. But even a winter averaging around or over 40° or warmer feels chilly outside and you will still need a jacket on most days. Newark Area, NJVersion: 18.2 (created 2023-09-05)Period of record: 1893 through 2022DateLowest minimum temperatures (degrees F) 10/25 31 in 1907 31 in 1903 33 in 1939+ 10/26 31 in 1952 31 in 1936 31 in 1933+ 10/27 27 in 1936 29 in 1976 29 in 1907 10/28 25 in 1936 27 in 1904 29 in 1976 10/29 29 in 1904 30 in 1965 30 in 1940 10/30 31 in 1952 31 in 1910 31 in 1902 10/31 27 in 1904 29 in 1975 30 in 1910+ Newark Area, NJPeriod of record: 1893-01-01 through 2023-10-22DateHighest maximum temperatures (degrees F) 10/25 79 in 2001 79 in 1963 78 in 2021 10/26 79 in 1964 79 in 1963 78 in 1989+ 10/27 81 in 1963 80 in 1947 78 in 1989 10/28 82 in 1984 81 in 1919 78 in 1989+ 10/29 78 in 1971 78 in 1946 76 in 1989 10/30 82 in 1946 80 in 1961 80 in 1950 10/31 82 in 1946 79 in 1950 77 in 1945

Nino 3.4 is struggling to get much past the 1.6 to 1.7 range on the dailies with the upper ocean heat so much lower than other strong El Niños. So the October daily peak was similar to September. Most El Niños show a decent jump from September to October. So the Euro seasonal is going to have one of its biggest misses on record for an October average forecast of 2.03. The CFS is actually going to be closer to the mark for its October forecast of 1.60. The current monthly average from OISST is 1.53. ECMWF 2.03 NCEP CFSv2 1.60 Current October OISST average 1.53.

Yeah, I had several posts showing the more south based based blocks with the warmer Atlantic SSTs in recent years. Also the tendency to get near record -AO months like last December with the NAO hardly going negative. The SW lean to the blocking is causing very large spreads between the AO and NAO. Some implicated the -PNA last December. But there were months in the older era with even deeper -PNAs that coincided with -AOs and colder NATL SSTs with blocks that didn’t build so close to New England. December 2022 2nd lowest December -AO on record behind 2009 and more south based block with the NAO hardly responding. AO -2.719 NAO..-0.15

Yes. The record NATL SSTs are probably the reason for the more south based blocking down to New England in recent years.

El Niños are usually cooler in the Southeast than the CPC and Euro seasonal. The colder departures further SW are more related the expectation on the Aleutian ridge north of Hawaii. This tends to promote downstream troughing near the SW instead of SE. Need a stronger Aleutian low north of Hawaii to keep the ridging near the East Coast in check.

That’s why I am not a big fan of the Aleutian ridge north or northwest of Hawaii. This persistent pattern for much of the last 8 winters tends to lower heights over the Western US and pumps the ridge in the Northeast. While the Euro seasonal raises the PNA in Canada, it still has the trough axis tucked underneath in the SW. The one hope is that we can cash in during any +PNA -AO intervals for a better snowfall outcome than last winter around NYC. But it would still be a record 9th warmer than average winter in the the Northeast if the trough axis remains near 115 west.

Yeah, the magnitude of the warmth increases the further north you get.

The warm departures on the warmer days will be more impressive than the cold departures on the colder days. That’s how the Northeast is on track for several stations having a top 10 warmest October. While the colder days have felt more fall-like, there has been no top 10 or record cold for this time of year.

We get the highs approaching 80° while Montana goes below 0°. Same old pattern of recent years with the cold dumping into the West. Plenty of time for the cold to moderate coming east. But we’ll still probably get 30s around NYC which will feel much colder following 80°.

I like the ensemble means better since those tercile maps lack the better definition.

The main challenge with the Euro seasonal is that it still has a trough near the SW in February. So storms ejecting from the SW could come out too far north without solid blocking on the Atlantic side. But I would still take my chances with that look compared to last winter. While it would be a record 9 warmer winters in a row for the Northeast, the snowfall would probably be better than last winter.