bluewave

It would have been a much better pattern back in the 50s to early 70s when the blocks weren’t as south based on average as recent years have been. The height rises to the east of New England don’t mix well with -PNA patterns like we saw in December. Even with the +PNA in December 2020, the track was just a little too tucked in near SNJ for Long Island to get into the best Jackpot zone near BGM. Plus just enough ridging to allow the record Christmas cutter a week later.

These are the days that surfers wish for all year.

On the whole, modeling has taken a big leap forward from the 60s and 70s. Now we can use a super ensemble to get a good track on a hurricane at even 5 days out. Plus ensembles can now identify general day 6-10 day patterns fairly well. But we have still been pushing up against the 15 day limit.

Nothing unusual about Newark this summer as some other stations had more 90° days. This was probably the result of the ASOS being so close to the bay and getting cooling breezes. Newark hasn’t had the 90° day lead NJ so far in the 2020s. Data for January 1, 2023 through September 15, 2023 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 ESTELL MANOR COOP 34 HARRISON COOP 33 HIGHTSTOWN 2 W COOP 31 NEWARK LIBERTY INTL AP WBAN 29 Newark Area ThreadEx 29 Data for January 1, 2022 through September 15, 2022 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 SOUTH JERSEY REGIONAL AIRPORT WBAN 52 HIGHTSTOWN 2 W COOP 49 NEWARK LIBERTY INTL AP WBAN 49 Data for January 1, 2021 through September 15, 2021 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 FREEHOLD-MARLBORO COOP 42 NEWARK LIBERTY INTL AP WBAN 41 Newark Area ThreadEx 41 HIGHTSTOWN 2 W COOP 40 Data for January 1, 2020 through September 15, 2020 Click column heading to sort ascending, click again to sort descending. Name Station Type Number of Days Max Temperature >= 90 HIGHTSTOWN 2 W COOP 42 FREEHOLD-MARLBORO COOP 40 HARRISON COOP 39 CANOE BROOK COOP 37 CALDWELL ESSEX COUNTY AP WBAN 37 ESTELL MANOR COOP 36 HAMMONTON 1 NE COOP 32 ATLANTIC CITY INTL AP WBAN 31 NEWARK LIBERTY INTL AP WBAN 31 Atlantic City Area ThreadEx 31 Newark Area ThreadEx 31

It’s funny how the OP Euro and machine learning models were both showing landfalls in SE New England in earlier runs before correcting further east toward the consensus. As to why this was the case, we can leave to the modelers writing the code. It may come down to the OP Euro being over amped at times for some reason. But this bias at times can work like in Sandy when the pattern was super amped up. So I guess some storms play to certain model biases depending on the situation. If they could train the AI to learn how and which biases to correct on a situational basis, then they will really have something. https://www.ecmwf.int/en/about/media-centre/news/2023/how-ai-models-are-transforming-weather-forecasting-showcase-data In a recent ECMWF blog and a Newsletter article, we’ve been highlighting the rapid rise of data-driven forecasts. These are produced by machine-learning-based forecasting models, created by innovators such as NVIDIA, Huawei and Google DeepMind. The ERA5 reanalysis, produced by the EU-funded Copernicus Climate Change Service (C3S) implemented by ECMWF, is the dataset used to train these models. They can make accurate 10-day forecasts when provided with good initial conditions. This summer, we focused on analysing Huawei’s Pangu-Weather to understand its strengths and weaknesses, with results collated in a submitted manuscript. At this early stage in the technology, some results are already displaying comparable skill to ECMWF’s Integrated Forecasting System (IFS), which is an exciting achievement.

That’s correct since the forcing took on more of a westerly lean this August than in 2009.

That 2nd lowest on record -2.1 last summer told us everything we needed to know about last winter well ahead of time. https://psl.noaa.gov/enso/mei/

The much warmer WPAC is holding the MEI back.

Yeah, looks like 80s will return on the warmer days but the higher minimums may drive the departures with high pressure shifting east of New England and onshore flow.

The WPAC was much cooler in 1997 so the forcing stayed further west this year.

The GFS did the best with the track of Lee. Maybe this was just the GFS right of track bias at work. Like the old broken clock is right twice a day metaphor.

Getting closer to our first +1.5 year.

The model looks like it’s going to be relatively close again based on the May melt pond data. The current daily extent is 4.31 million sq km. So another normal September by post 2012 warmer and thinner sea ice standards. Which means that when September gets averaged out, it should fall somewhere in the 4s. Tough to get below 4 or above 5 these days for a September average extent.

Seasonal snowfall forecasting for a place like Islip in Suffolk County NY used to be much easier before the 93-94 winter. It has been truly feast or famine since then. Guessing the seasonal snowfall totals before then was much easier with so many mid range winters. Way too much volatility these days to guess whether it will be well above or below before the season starts. Record highs and lows in terms of storms and seasons have become the new norm. 93-94 to 22-23 29….seasons with over 33” or under 15” 1…….season with between 15” to 33” 63-64 to 92-93 12….seasons over 33” or under 15” 18…..seasons between 15” to 33”

I am trying not to envision anything like last winter. My point is that every winter since the 15-16 super El Niño reset has had some element of the WPAC warm pool La Niña flavor. So no mater what the ENSO does, we have had a record breaking 8 warmer than normal winters in a row. While I have gotten used to that, it isn’t easy going nearly snowless like last winter. So we need just enough -AO -NAO blocking on the Atlantic side and enough +PNA or -EPO blocking on the Pacific side to have one or a few KU events. Just way too many elements in the mix these days to say with confidence what version of winter is going to show up ahead of time. There have been no winters with a moderate amount of snow at ISP on Long Island since the late 90s. Every winter since then has been all or nothing with the snowfall. Either at least one record breaking KU event and above normal snowfall or next to nothing and well below normal snowfall. The median snowfall winter which was the mainstay from the 60s to 90s has been nowhere to be found. So how you issue a snowfall forecast in the fall and know with confidence which type of season is going to show has been very tough to do. In the old days, you could go with a median snowfall forecast winter and have a reasonable chance of being correct.

We just don’t know what to expect for the winter yet so it’s all guesswork. If we can get enough dominant WPAC forcing just west of the Dateline, then that would lead to +PNA intervals. If the summer Aleutian Low position is informative, then the vortex could hang back near the Bering Sea. My guess is that we get more +PNA than last winter. But the degree of El Niño coupling will be important as to how much MJO 4-6 forcing we get. We got a full month of super La Niña-like conditions during the 15 -16 super El Niño in 14-15. Then a great January and February Nino pattern with blocking. So that coupled event gave us two favorable months and one unfavorable. Not sure what that ratio would look like during the winter since we currently have weaker coupling. Some decent blocking analogs looking at past Julys with such a low -NAO. But we would more +PNA to make any blocking intervals more productive.

The is more of a split flow pattern with the northern PAC Jet remaining more active which will carve out the big -PNA +EPO trough next few weeks. If this was winter, we would be asking when the raging Pacific Jet will relax and let the STJ dominate. Still early but we can already see the potential bag of competing influences we may have to deal with. Very extensive block of forcing from the Indian Ocean into the WPAC. Unfortunately, just enough MJO 4-6 forcing action to really pump the SE Ridge.

This is something new. I left off 2023 since we are only halfway through the month. But we are on track for another top 5 or 10 warmest September. The average temperature will easily remain above 70°. Notice the big 2° jump in average temperature since 2010. Prior to that, the decadal averages were fairly steady from 1980 to 2009. Slower but steady temperature increase from 1950 to 1980. I am guessing this is a function of the rapidly warming SSTs to our east possibly in conjunction with the lower Arctic sea ice and warmer summers. So not much cold available to get fall going in September anymore. We tend to have later fall foliage peaks and leaf drops. Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Sep Season Mean 70.7 70.7 2022 69.7 69.7 2021 72.5 72.5 2020 69.1 69.1 2019 70.8 70.8 2018 71.4 71.4 2017 70.9 70.9 2016 71.8 71.8 2015 73.4 73.4 2014 69.8 69.8 2013 67.2 67.2 2012 69.5 69.5 2011 71.2 71.2 2010 71.6 71.6 Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Sep Season Mean 68.9 68.9 2009 66.9 66.9 2008 69.5 69.5 2007 70.1 70.1 2006 66.6 66.6 2005 73.5 73.5 2004 69.6 69.6 2003 68.6 68.6 2002 70.5 70.5 2001 67.4 67.4 2000 66.4 66.4 Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Sep Season Mean 68.8 68.8 1999 69.3 69.3 1998 70.3 70.3 1997 66.9 66.9 1996 68.0 68.0 1995 68.6 68.6 1994 69.7 69.7 1993 69.1 69.1 1992 69.6 69.6 1991 67.9 67.9 1990 68.6 68.6 Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Sep Season Mean 68.6 68.6 1989 69.9 69.9 1988 68.0 68.0 1987 68.7 68.7 1986 68.5 68.5 1985 70.2 70.2 1984 65.4 65.4 1983 70.6 70.6 1982 66.7 66.7 1981 67.1 67.1 1980 70.8 70.8

Septembers have been getting steadily warmer since the 80s and 90s. Most of the Septembers in recent years have averaged over 70° around NYC. So plenty of top 10 warmest Septembers.

Right back to the endless summer pattern after several days closer to average. Big -PNA trough will pump the SE Ridge later in the month. September since 2010 has been more a more like a summer month rather than a fall month.

I think we will be OK on the forcing provided the main VP anomalies don’t stray too far from Nino 4 like we have been seeing. Nino 4 finished August 2nd warmest to 2015 with SSTs just under +30C.

https://repository.library.noaa.gov/view/noaa/32935 Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle https://iopscience.iop.org/article/10.1088/1748-9326/ac5edf/meta Abstract The Indo-Pacific warm pool (IPWP) has warmed and expanded substantially over the past decades, which has significantly affected the hydrological cycle and global climate system. It is unclear how the IPWP will change in the future under anthropogenic (ANT) forcing. Here, we quantify the human contribution to the observed IPWP warming/expansion and adjust the projected IPWP changes using an optimal fingerprinting method based on Coupled Model Intercomparison Project phase 6 (CMIP6) simulations. We find that more than 95% rapid warming and 85% expansion of the observed IPWP are detected and attributable to human influence. Furthermore, human activities affect IPWP warming through both greenhouse gases and ANT aerosols. The multiple model ensemble mean can capture the ANT warming trend and tends to underestimate the ANT warming trend. After using the observation constraint, the IPWP warming is projected to increase faster than that of the ensemble mean in the 21st Century, and the Indian Ocean warm pool is projected to expand more than previously expected. The rapid warming and expansion of IPWP over the rest of the 21st century will impact the climate system and the life of human beings.

New England has been getting some of the most extreme rainfall recently.

Hopefully, the more Niña-like -PNA +EPO -PDO pattern in late September turns out to be transitory. At the very least, that will put the brakes on any major Nino warming like we had in August for the time being. The unusually strong trades for an El Niño have picked up again in September after they tried to behave more Nino-like back in August. https://coralreefwatch.noaa.gov/product/5km/index_5km_ssta.php