bluewave

We would need to see all that IO forcing shift east toward the Maritime Continent in October. The big amped up MJO 5 in October 2017 came before the snowy La Niña 17-18 winter. The strong IO MJO 1 in October 2011 preceded the 11-12 La Niña winter. There is some research that early IO forcing can excite the PV like we saw last winter.

We’ll see if we can get some early hints from the MJO in October. The 18-19 and 19-20 below normal snowfall La Niña background state winters featured the October MJO convection focused in the Indian Ocean. Our snowier 16-17 and 17-18 La Niña winters had the October MJO in the Maritime Continent phases.

Yeah, it does look like that big Western Ridge builds again to close out the month. So a deep trough in the Great Lakes would probably mean a wetter pattern for us. Any remnant tropical moisture from BETA would enhance our rainfall prospects.

The Euro and GFS have us getting back to the 80s by later in the week. But it looks like we will come up short on reaching 90°. So this could be the first fall since 2011 without any 90° degree days at Newark. The last fall at LGA without any 90s was 2012. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Sep through Nov Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2020 0 72 2019 4 0 2018 4 0 2017 3 0 2016 5 0 2015 5 0 2014 3 0 2013 1 0 2012 2 0 2011 0 0 2010 6 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Sep through Nov Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2020 0 72 2019 3 0 2018 4 0 2017 1 0 2016 3 0 2015 3 0 2014 2 0 2013 1 0 2012 0 0 2011 0 0 2010 4 0

Looks like the first 26° September dew point at Newark since the late 90s. Newark/Liberty MOSUNNY 64 26 23 N12 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=159&network=NJ_ASOS&zstation=EWR&var=dwpf&dir=below&thres=27&month=sep&year=2020&dpi=100&_fmt=png

The low of 50° in NYC was the coldest September temperature since 2013. Early Sunday could be a degree or two cooler. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Sep Click column heading to sort ascending, click again to sort descending. Year Lowest Min Temperature Missing Count 2020 50 11 2019 52 0 2018 54 0 2017 54 0 2016 54 0 2015 56 0 2014 52 0 2013 47 0

That was the great episode that the starfish clip posted above was from. https://www.pbs.org/wnet/nature/the-serengeti-rules-41dfru/20105/

Yeah, they believe that it’s related to the record marine heatwave. https://advances.sciencemag.org/content/5/1/

It would be great if they could find a way to install one of these near an open section of Central Park. https://www.newswise.com/articles/nys-mesonet-con-edison-partner-to-launch-nyc-micronet-weather-observation-network Newswise — ALBANY, N.Y. (Sept. 9, 2020) – A new cluster of weather-monitoring stations will offer New York City’s energy provider real-time data to keep service reliable and resilient for its customers. Con Edison, the energy company that serves New York City and Westchester County, is working with the University at Albany’s New York State Mesonet on the “New York City Micronet,” a new network of 17 weather-monitoring stations that will be located at company properties in the City’s five boroughs. The NYC Micronet, also supported by UAlbany’s Center of Excellence in Weather and Climate Analytics, will help Con Edison monitor high-impact weather events and track long-term climatic changes. Con Edison is investing $3 million in the network. That includes a $1.6 million contract with the University. Installation started this month. The network is expected to be completed by the end of October. “This partnership with Con Edison is the latest example of NYS Mesonet providing a service to make our state more resilient to increases in weather extremes and to better inform weather risk-management decisions,” said Chris Thorncroft, director of UAlbany’s Atmospheric Sciences Research Center, the NYS Mesonet and Center of Excellence. “UAlbany has direct access to the largest concentration of atmospheric, climate and environmental researchers in New York. We are continuing to create smart business solutions to empower industry partners statewide.” “Climate change makes smart infrastructure planning and design essential,” said Charles Viemeister, Con Edison’s project manager. “We’ll use data from the Micronet to gain additional insight into the local short-term and longer-term impacts of climate change. We are always looking for technologies that can help us maintain the resilient, reliable service our customers need.” The NYS Mesonet is the most advanced and largest early warning weather detection network in the nation. Its standard 126 weather stations, located across the state and in every county, offer real-time data on a number of weather variables including temperature, humidity, wind speed and direction, pressure, precipitation, snow depth and soil moisture. Each station is also equipped with a camera for real-time photos. UAlbany’s Center of Excellence in Weather & Climate Analytics is New York’s entrepreneurial hub for a network of more than 120 weather and climate faculty, researchers and research staff. Together, these experts are deeply engaged in advancing innovative weather and climate research applications for a variety of industries including utilities, agriculture, renewable energy, emergency management, transportation and Unmanned Aerial Systems. During the COVID-19 crisis, they have supported all New York utilities by providing a sophisticated weather dashboard to enhance situational awareness. The NYC Micronet is a customized version of NYS Mesonet’s standard network and will undergo the same regular maintenance, data quality control, sensor calibrations, and visualization, performed daily at UAlbany’s Mesonet Operations Center and by technicians in the field. This project adds to an already established relationship between UAlbany and Con Edison. In 2019, the two partners, along with MESO, Inc. created the Wind Extremes Forecast System (WEFS). It uses a combination of regional NYS Mesonet data and machine learning techniques to produce forecasts of threshold wind speeds and gusts that could lead to power outages at county and sub-county levels in New York State. “The goal, with both the Micronet and WEFS, is to provide NYC’s primary utility provider with valuable environmental data that can help improve resiliency for its services and mobilize resources more efficiently when severe weather strikes,” said Jerry Brotzge, NYS Mesonet program manager. “Our weather stations are quietly driving decision-making in a variety of sectors.” NYS Mesonet data and visualizations are available for viewing at www.nysmesonet.org https://qns.com/2020/09/con-edison-to-install-eight-weather-stations-in-queens-to-better-track-climate-trends/ In order to better understand climate trends and protect its power systems, Con Edison has partnered with the State University of New York at Albany and invested $3 million to install eight weather stations across Queens and nine more across New York, the power company announced this week. The New York City Micronet project will see weather stations installed in Flushing, Long Island City, Astoria, Howard Beach, South Ozone Park and Maspeth. The data from the stations will help Con Edison guide its investments towards protecting its energy-delivery systems from severe weather events, according to the company. A record number of Con Edison customers in the New York City area lost power during Tropical Storm Isaias in early August, including 73,000 customers in Queens. However, the installation of the weather stations is unrelated to the damage caused by Isaias, according Con Edison. The power stations were in progress prior to Isaias and are instead a response to all of the severe weather New York City has experienced in the past decade, a representative for the company said. “Climate change makes smart infrastructure planning and design essential,” said Charles Viemeister, Con Edison’s project manager. “We’ll use data from the Micronet to gain additional insight into the local short-term and longer-term impacts of climate change. We are always looking for technologies that can help us maintain the resilient, reliable service our customers need.” The weather stations will monitor temperature, air pressure, wind speeds and direction, precipitation and other weather variables. Six of the stations will be installed on the roofs of Con Edison buildings and the other 11 will be installed at ground level on Con Edison property. The data collected by the weather stations will be sent to the university, which will in turn give the data to Con Edison and be made available to the public, the company said. Con Edison expects the weather stations to be installed and fully operational by the end of 2020. In addition to the weather stations, Con Edison has begun to make upgrades to its energy delivering system in Westchester County, which was heavily affected by Tropical Storm Isaias. The power company also recently commissioned a weather study, which suggested the company make an investment between $1.8 billion and $5.2 billion by 2050 on targeted programs to protect its systems against severe weather events.

Saturday could be the earliest 50° of the season in NYC since 2013. New York City... Central Park, NY Mocldy Mocldy Sunny Sunny Sunny Sunny Sunny /78 61/67 50/66 50/66 51/67 52/70 54/76 /10 30/30 10/00 00/00 00/00 00/10 10/10 First/Last Summary for NY CITY CENTRAL PARK, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Difference Minimum 05-14 (2017) 09-17 (2013) 113 Mean 05-20 10-03 135 Maximum 06-02 (2015) 10-13 (2018) 146 2019 05-15 (2019) 44 10-04 (2019) 50 141 2018 05-19 (2018) 49 10-13 (2018) 46 146 2017 05-14 (2017) 46 10-01 (2017) 50 139 2016 05-16 (2016) 43 10-10 (2016) 47 146 2015 06-02 (2015) 50 10-02 (2015) 48 121 2014 05-19 (2014) 49 10-05 (2014) 46 138 2013 05-26 (2013) 48 09-17 (2013) 50 113

Changes to nature that seem small can have very big consequences.

https://wcd.copernicus.org/preprints/wcd-2020-40/ https://wcd.copernicus.org/preprints/wcd-2020-40/wcd-2020-40.pdf Global warming makes weather in boreal summer more persistent Dim Coumou1,2† and Paolo De Luca1† 1Department of Water and Climate Risk, Institute for Environmental Studies (IVM), Vrije Universiteit Amsterdam, Amsterdam, 1081 HV, the Netherlands 5 2Royal Netherlands Meteorological Institute (KNMI), De Bilt, 3730 AE, the Netherlands †These authors contributed equally to the work Correspondence to: Dim Coumou ([email protected]) Abstract. Extreme summer weather often has devastating impacts on society when it lasts for many days. Stalling cyclones can lead to flooding and persistent hot-dry conditions can lead to health impacts and harvest losses. Global warming weakens the hemispheric-wide circulation in boreal summer, which has been shown in both observations and models using multiple circulation metrics. Until now, it is still largely unclear what this weakening implies for regional weather conditions, including their persistence. Using an advanced persistence metric, we show that summer weather has become more-persistent over 1979-2019. State-of-the-art climate models reproduce this upward trend in persistence indicating that it can be attributed to greenhouse gas forcing. Our persistence metric accounts for the full state of the atmosphere at any given moment and is strongly rooted in dynamical systems theory. Thereby it is able to detect dynamical changes previously unseen in more widely used clustering analyses that sharply reduce the amount of information used. We show that under future high-emission scenarios, summer weather will become increasingly more-persistent due to a weakening of the circulation. Most of this increase in persistence, and the associated societal risks, is avoided under an emission scenario compatible with the Paris agreement.

Looks like ISP made it down to 50°. Getting closer to the average first 40s date of the season since 2010. First/Last Summary for ISLIP-LI MACARTHUR AP, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Difference Minimum 05-13 (2011) 09-02 (2017) 85 Mean 05-29 09-20 113 Maximum 06-12 (2018) 10-12 (2018) 131 2019 06-04 (2019) 46 09-19 (2019) 46 106 2018 06-12 (2018) 48 10-12 (2018) 49 121 2017 06-08 (2017) 47 09-02 (2017) 49 85 2016 05-23 (2016) 49 09-25 (2016) 48 124 2015 05-23 (2015) 48 10-02 (2015) 49 131 2014 06-01 (2014) 49 09-23 (2014) 45 113 2013 05-28 (2013) 48 09-09 (2013) 49 103 2012 06-06 (2012) 49 09-17 (2012) 49 102 2011 05-13 (2011) 47 09-19 (2011) 49 128 2010 05-20 (2010) 49 09-16 (2010) 47 118

The NYC 4th longest 70° degree streak finallly ended. Number of Consecutive Days Max Temperature >= 70 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 118 2015-09-30 2 117 1995-09-22 - 117 1994-09-21 3 115 1925-09-21 4 113 2020-09-14 - 113 2008-09-18 5 111 2016-09-27 - 111 1966-09-19

New lowest extent record for the Central Arctic.

Earliest first 40s of the season at HPN since 2014. First/Last Summary for WESTCHESTER CO AP, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Difference Minimum 05-13 (2011) 09-09 (2013) 97 Mean 05-30 09-20 113 Maximum 06-12 (2018) 10-12 (2018) 126 2019 06-04 (2019) 47 09-19 (2019) 43 106 2018 06-12 (2018) 49 10-12 (2018) 47 121 2017 06-09 (2017) 47 09-29 (2017) 47 111 2016 05-21 (2016) 48 09-25 (2016) 44 126 2015 06-02 (2015) 48 09-27 (2015) 47 116 2014 06-01 (2014) 48 09-14 (2014) 48 104 2013 05-28 (2013) 49 09-09 (2013) 49 103 2012 06-05 (2012) 49 09-11 (2012) 46 97 2011 05-13 (2011) 48 09-16 (2011) 48 125 2010 05-20 (2010) 49 09-16 (2010) 47 118

Could be the first September under 70° in NYC since 2014. A +2 in September for NYC is 70°. So anything below that will do it. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Sep Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2020 72.8 16 2019 70.4 0 2018 70.7 0 2017 70.5 0 2016 71.8 0 2015 74.5 0 2014 69.7 0 2013 67.9 0 2012 68.8 0

The smoke shows up really well on the satellite image.

08-09 was our last winter without some type of wild extreme.

It will be interesting to see. 08-09 finished closer to normal in the snowfall department. It was one of the few closer to average snowfall seasons in a sea of below and above normal snowfall extremes. So like you said, many here would be happy with a season like that after the last two.

Still early to guess at any analog types. But winters have been following a 1 or 2 year pattern for a while now. So it will be interesting to see if this winter reverts back to a snowier La Niña or does a rare 3 below normal snowfall seasons. We haven’t gone below normal for snowfall during 3 consecutive seasons since the late 90s. 19-20....18-19....Niña-like above normal temperatures and below normal snowfall 17-18.....16-17...La Niña above normal temperatures and snowfall 15-16..................Super El Niño with above normal temperatures and snowfall 14-15.....13-14....Record + North Pacific Mode with below normal temperatures and above normal snowfall. Also remembered as the record NEPAC warm blob winters. 12-13.....Niño-like above normal temperatures backloaded snowfall 11-12.....La Niña with above normal temperatures and below normal snowfall 10-11....09-10.....record -NAO and -AO with an El Niño then La Niña ....below normal temperatures and above normal snowfall.

With these Niña-like winter patterns, it really comes down to how far north the Pacific ridge extends. When it builds northward into Alaska, we can get -NAO intervals and snowier winters. But when that ridge flattens out north of Hawaii, we often get a strong +EPO/+NAO and well below normal snowfall. Near to above normal snowfall La Niña composite Below normal La Niña snowfall composite

Anything below +2 to +6 is considered cool by recent September standards. We would have to go back to 2013 to 2014 for departures under those levels. A continuation of less warm is the new cool. SEP....EWR...NYC...LGA 2019...+2.6....+2.4....+3.0 2018...+3.2...+2.7....+3.7 2017...+2.7...+2.5....+2.4 2016...+3.6...,+3.8...+4.7 2015...+5.2....+6.5...+5.0 2014..+1.6....+1.7....+1.3 2013...-1.0....-0.1.....-1.0 2012...+1.3...+0.8....+3.4 2011....+3.0..+2.0....+1.6 2010...+3.4....+3.1...+3.4

Big interior radiational cooling event in the forecast for next weekend. Temperatures should be even cooler than on Tuesday morning. So more fall-like temperatures after a warm start to September.

The NPM is remaining strongly positive even with the developing La Niña and -PDO. At least right now, we are getting more ridging out there than we typically see this time of year with a La Niña. But it’s still too early to know if this is a temporary pattern or can hold on into the fall and winter. Last winter the NPM dropped as the +EPO vortex took over.