bluewave

The 15-16 super El Nino was the only warm ENSO event in the last decade that the models didn’t have a warm bias for. So that’s why I like to take a wait and see approach as to how strong this event gets. Looks like after the current WWB coming through we go back to some weaker trades again. This current WWB was also displaced closer to 1+2 and 3 and less impressive near the Dateline like we have been seeing.

My main concern with the model forecasts from July was the only models showing a super El Niño had August above +1.5. August is set to come in under +1.5 on OISST which I believe has been running a little warmer than the official ERSST. I know other models have warmed in August. But we don’t have the September verification yet to judge them by. July models showing super El Niño and their August forecast AUS…………..1.93 ECMWF……..1.67 Metfrance….1.95

We have been past the spring forecast barrier several times over the last decade and the actual pattern has gone against what the ENSO models were showing as late as August or the early fall. The ENSO models haven’t been doing too well this summer with 3.4. The SSTs have come in much cooler than the forecasts from June and July were indicating. But Nino 1+2 has stayed warmer longer than the model forecasts. Plus the forcing forecasts verified further west than most of the guidance. So it’s not unreasonable to think that there will be more errors of some type with model forecasts going forward. I am not doubting the super El Niño forecasts because of any attachment to a cold winter. We haven’t had a cold winter since 14-15 in the Northeast. So I have gotten used to milder winters over the years. But we have seen many incorrect model ENSO forecasts since 2012-2013 which needs to be taken into account when viewing these model outputs.

My only hesitancy in buying the models showing a super El Niño is how much cooler the subsurface is than at this point than in August 2015 and 1997. So not sure if several of the ENSO SST forecasts are still showing excessive momentum. The present heat values are less than half what they were in 1997 and 2015. I know we have a small sample size of super El Niño so there could be more variation in subsurface patterns than we have seen in the past.

Yeah, we can see how serious the flash flooding was in Death Valley last summer when they had their historic rainfall which was lower than is being projected with Hillary.

Several locations in the Northeast have had their wettest summer so far from June into Mid-August.

It will be their version of a Harvey or Florence with a year of rainfall for those areas in just a few days.

Yeah, I am hoping we get some piece of the summer to winter blocking carryover even if we have warmed quite a bit from several of the past years. A warmer version could still produce better snowfall than last winter. Just cold enough has worked for us with a raging STJ and even a small amount of blocking. Many would accept another mild winter if we can get a decent snowstorm or two.

February 2015 was probably the biggest fluke since 2000. Some of the papers I read pinned the 13-14 and 14-15 mega NE PAC Ridge on the warmer waters near 15N in the WPAC. It’s interesting that the forcing emanating from just 15 degrees further south along the equator in the WPAC creates such a warmer response for us with the frequent MJO 4-6 transits over the last 8 winters.

Close to normal for the much warmer 1991-2020 climate normals. But warmer than average for the previous 30 year normals. So NOAA and the NCDC are inadvertently doing their part to normalize the warmer climate like the public does. Very difficult to use 30 year normals in such a rapidly warming climate. They worked better when the climate was more stable.

Its possible that there could be a period of Nina-like forcing like we saw during the super El Niño back in December 2015. The WPAC has been doing its own thing in recent years. It was the first strong MJO 4-6 in a super El Niño.

It’s better to dense rank weather statistics since the actual ranking is based on temperature and not the year. This is how the NWS NY out in Upton ranks their top temperature and precipitation records. https://www.sqlservertutorial.net/sql-server-window-functions/sql-server-dense_rank-function/

This is a great place for weather stats. But much of the world doesn’t pay attention to the details like we do here. So people rapidly normalize a changing climate and miss the perspective and context of the changes. Plus the migration patterns in the US are toward warmer climates. So many are fine with mild and snowless winters and would be happier if they lived year round in places like Florida.

The subsurface is a bit perplexing compared to years that went super. While the OISST Nino 3 is near +2 and 3.4 is getting closer to +1.5, the subsurface is much less impressive than super El Niño summers at this point. So I think it’s going to be more difficult to predict the specifics this year compared to other strong to super years. While we have the +IOD developing, it’s only showing a relatively small region of cooling SW of Indonesia. The WPAC in general is much warmer than most very strong El Niño years. So the low skill seasonal models may even be if less use this year than other years.

We normalize the record warmth fairly quickly. So when we have temperatures cooler than those years, it feels cooler relative to the warmer years. It’s one of the reasons that climate change doesn’t interest as many people compared to other issues. https://www.sciencedaily.com/releases/2019/02/190225170252.htm Tweets tell scientists how quickly we normalize unusual weather Study: 'Remarkable' weather becomes normal within a few years Date: February 25, 2019 Source: University of California - Davis

The planet has warmed so much since those top 10 coolest El Niño onset summers of days past. 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 Jun 1 to Aug 17 Missing Count 1 1964-08-17 68.6 0 2 1965-08-17 68.8 0 3 1992-08-17 69.0 0 4 1979-08-17 69.3 0 - 1972-08-17 69.3 0 5 2009-08-17 69.5 0 6 1982-08-17 69.6 0 - 1968-08-17 69.6 0 7 1978-08-17 69.8 0 8 1996-08-17 69.9 0 9 2004-08-17 70.0 0 10 1985-08-17 70.2 0

Einstein was right. It’s all relative. . A 14th warmest summer average temperature at Islip so far feels much cooler than all the top 5 warm recent years. 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 Jun 1 to Aug 17 Missing Count 1 2010-08-17 75.1 0 - 1999-08-17 75.1 0 3 2020-08-17 74.7 0 4 2011-08-17 74.3 0 5 2022-08-17 74.1 0 - 2019-08-17 74.1 0 - 2016-08-17 74.1 0 6 1994-08-17 73.6 0 7 2013-08-17 73.5 0 - 2012-08-17 73.5 0 - 2008-08-17 73.5 0 8 2018-08-17 73.4 0 9 2005-08-17 73.3 0 - 1988-08-17 73.3 0 10 2006-08-17 73.2 0 - 1991-08-17 73.2 0 - 1966-08-17 73.2 0 11 2021-08-17 73.1 0 12 2002-08-17 73.0 0 - 1995-08-17 73.0 0 13 2015-08-17 72.8 0 - 2014-08-17 72.8 0 - 1980-08-17 72.8 0 14 2023-08-17 72.7 0

Much warmer west and cooler east than at this point in 1997. That’s why the forcing has been much further west this summer. The present Nino 4 is near record levels of warmth for this time of year. So while the highest departures are in 1+2 and 3, Nino 4 is warmer for actual SSTs. The much cooler subsurface than in 1997 suggests that 1+2 and 3 will peak earlier this year than 97-98 did. The main question is whether we can get a fall (SON) peak instead of winter for 1+2 and 3 which would influence the all important winter forcing location. 97-98 featured a 1+2 peak in NDJ.

On par with 2017 and 2014 for Long Island but well above a really cool summer like 2009. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Mean Avg Temperature Jun 1 to Aug 17 Missing Count 2023-08-17 72.7 0 2022-08-17 74.1 0 2021-08-17 73.1 0 2020-08-17 74.7 0 2019-08-17 74.1 0 2018-08-17 73.4 0 2017-08-17 72.3 0 2016-08-17 74.1 0 2015-08-17 72.8 0 2014-08-17 72.8 0 2013-08-17 73.5 0 2012-08-17 73.5 0 2011-08-17 74.3 0 2010-08-17 75.1 0 2009-08-17 69.5 0

Yeah, how posters evaluate what constitutes a hot summer or good winter is very subjective. Some people only consider a high number of 90s or several 100° days hot like we had last summer. Even though the record dewpoints made it feel like we had a higher number of 90° days. Plus June and August didn’t have much in the way of heat compared to some recent years. Winter ratings can be even more tricky. I actually enjoyed the 15-16 winter more than the 14-15. Even though we averaged over 40° with a +13 December, the January record snowstorm jackpot near 30” in NYC Metro was more impressive to me. It made up for the model error with the January 2015 event going further east. Plus that big event was more memorable than several smaller to moderate events the previous winter. The NYC below 0° fans finally got their due on Valentine’s Day. Even with the 2nd coldest February the year before, the NYC temperature couldn’t fall below 0° like it did during the much warmer 15-16 winter.

The record 600 dm ridge stays to our west.

The 5 year reduction in snowfall on Long Island was more pronounced. The record 5 year period from 13-14 to 17-18 averaged 54.8” at Islip. Big reduction down to only 19.0” since 18-19. The 5 year average snowfall in NYC dropped from 42.3” down to 16.8”. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season Mean 0.9 2.5 7.3 6.9 1.5 T 19.0 2022-2023 0.0 0.4 T 3.0 1.6 0.0 5.0 2021-2022 T 0.3 31.8 3.3 1.6 0.0 37.0 2020-2021 0.0 7.5 1.1 24.9 T T 33.5 2019-2020 0.1 4.2 2.5 0.0 T T 6.8 2018-2019 4.3 T 0.9 3.5 4.1 T 12.8 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season Mean 0.1 3.5 23.2 13.4 13.5 1.0 54.8 2017-2018 T 6.0 22.0 1.4 31.9 4.6 65.9 2016-2017 T 3.2 14.0 14.7 7.4 T 39.3 2015-2016 0.0 T 24.8 13.2 3.2 0.2 41.4 2014-2015 T 0.4 30.2 13.4 19.7 0.0 63.7 2013-2014 0.3 8.1 25.2 24.5 5.4 0.2 63.7 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season Mean 1.3 2.6 4.2 6.6 2.2 T 16.8 2022-2023 0.0 T T 2.2 0.1 0.0 2.3 2021-2022 T 0.2 15.3 2.0 0.4 0.0 17.9 2020-2021 0.0 10.5 2.1 26.0 T 0.0 38.6 2019-2020 0.0 2.5 2.3 T T T 4.8 2018-2019 6.4 T 1.1 2.6 10.4 0.0 20.5 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season Mean 0.0 4.1 16.7 12.2 8.2 1.1 42.3 2013-2014 T 8.6 19.7 29.0 0.1 T 57.4 2014-2015 0.2 1.0 16.9 13.6 18.6 0.0 50.3 2015-2016 0.0 T 27.9 4.0 0.9 T 32.8 2016-2017 T 3.2 7.9 9.4 9.7 0.0 30.2 2017-2018 T 7.7 11.2 4.9 11.6 5.5 40.9

Regardless of the ENSO state, the Northeast has had 8 warmer than normal winters in a row. We have had various flavors of La Niña with a super El Niño and uncoupled El Niño states. Snowfall was outstanding through 17-18. Then we entered a less snowy period since 18-19. What would work for us with and El Niño would be a raging STJ carving out a SE Trough with blocking. That would mute the influence of the SE Ridge. But we saw in December 2015 how we got the unfavorable MJO 4-6 which pumped the SE Ridge to record levels. We got a great pattern during that January and February when the SE Ridge was muted and we had a strong block across the pole.

The forcing is still a little further west than we typically see with an El Niño in August. This is closer to the actual warmest SSTs. Still to early to tell exactly where the forcing will line up for the winter.