bluewave

https://www.njherald.com/news/20200909/summer-2020-was-second-hottest-on-record-in-new-jersey New Jersey experienced its second-hottest summer on record, continuing a long-term warming trend in the Garden State and across the planet that has seen sea levels rise and extreme weather become more common. The average temperature statewide soared to 75.3 degrees from June through August, ranking only behind 2010′s record-setting heat, according to a report released Tuesday by Rutgers University. Climate change is being felt increasingly in New Jersey, with the 10 hottest summers having all occurred since 1999, including seven since 2010, said David Robinson, the state climatologist and author of the report. A full list is below. “It’s indicative of what we’re seeing in other seasons in New Jersey, what we’re seeing nationally and what we’re seeing globally,” Robinson said. “It’s just another sign that climate change is here.” This summer’s milestone was not much of a surprise considering that July was the hottest month ever recorded in New Jersey. August 2020 was tied for the sixth-warmest August on record, and June was the 10th-warmest it’s been since record-keeping began in 1895.

50 years is not cherry picking. It represents the time of most rapid global warming as emissions have increased. The actual charts with trend lines are available at the NCDC site. New Jersey is one of the sates that you posted and summers have been warming at 0.3° F decade since 1895. This year was the 2nd warmest summer on record in NJ. Notice how many of the top 10 warmest summers have occurred in recent years. https://www.ncdc.noaa.gov/cag/statewide/time-series/28/tavg/3/8/1895-2020?trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2020 201006 - 201008 75.7°F 126 202006 - 202008 75.3°F 125 201606 - 201608 74.9°F 124 200506 - 200508 74.8°F 123 201106 - 201108 74.6°F 122 201806 - 201808 74.4°F 121 201906 - 201908 74.4°F 121 199906 - 199908 74.3°F 119 201206 - 201208 74.2°F 118 200206 - 200208 74.0°F 117

It will be interesting to see how much longer this continues before it gets overpowered by warming. But how does agriculture cause increased rainfall and decreased temperatures? The team suspects it has to do with photosynthesis, which leads to more water vapor in the air. When a plant’s pores, called stomata, open to allow carbon dioxide to enter, they simultaneously allow water to escape. This increases the amount of water going into the atmosphere and returning as rainfall. The cycle may continue as that rainwater eventually moves back into the atmosphere and causes more rainfall downwind from the original agricultural area. Rong Fu, a climate scientist at UC Los Angeles, agrees with the team’s assessment. She also thinks that though human influence might be “greater than we realize,” this regional climate change is probably caused by many factors, including increased irrigation in the region. “This squares with a lot of other evidence,” says Peter Huybers, a climate scientist at Harvard University, who calls the new study convincing. But he warns that such benefits may not last if greenhouse gas emissions eventually overpower the mitigating effect of agriculture. Alter agrees, and says it’s unlikely that the large increases in U.S. crop production during the 20th century will continue. Other scientists have voiced concern that agricultural production could soon be reaching its limit in many parts of the world. “Food production is arguably what we’re more concerned about with climate change,” Mueller says. And understanding how agriculture and climate will continue to affect one another is crucial for developing projections for both climate and agricultural yields. “It’s not just greenhouse gasses that we need to be thinking about. While the cooling effect of irrigation mitigates global climate change on the regional scale, climate models suggest that regional warming attributed to the global trend will eventually overcome the magnitude of mitigation offered by irrigated agriculture. Farmers, who are partially buffered for now from more extreme heat, would quickly face increasing stress in that scenario. “Farmers in irrigated regions may experience more abrupt temperature increases that will cause them to have to adapt more quickly than other groups who are already coping with a warming climate,” says Kucharik. “It’s that timeframe in which people have time to adapt that concerns me.” The current study is the first to definitively link irrigation in the Midwest U.S. to an altered regional climate. These results could improve weather and climate forecasts, help farmers plan better, and, the researchers hope, better prepare agricultural areas to deal with a warming climate when the irrigation effect is washed out. “Irrigation is a land use with effects on climate in the Midwest, and we need to account for this in our climate models,” says Nocco.

The record breaking ridge centered near the Pacific Northwest Is a big change from the recent September decadal pattern. That area has usually experienced a trough during September. So it will be interesting to see if this temporary or has lasting potential through the fall and winter. This pattern keeps generating very strong highs that roll across the Northern US.

This is one of those times that a firehose Pacific Jet can help bring a series of cold fronts across the country.

The Euro has Canadian high pressure dominating into late September. So it’s possible that we had an early last 90° of the season back in late August. It would be the earliest last 90° at Newark since 2011. First/Last Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value Last Value Difference Minimum 04-07 (2010) 08-08 (2011) 69 Mean 05-21 09-12 113 Maximum 06-17 (2014) 10-02 (2019) 170 2019 05-26 (2019) 90 10-02 (2019) 96 128 2018 05-02 (2018) 90 09-06 (2018) 98 126 2017 05-17 (2017) 92 09-25 (2017) 90 130 2016 05-25 (2016) 91 09-23 (2016) 90 120 2015 05-25 (2015) 90 09-09 (2015) 91 106 2014 06-17 (2014) 91 09-06 (2014) 95 80 2013 05-30 (2013) 93 09-11 (2013) 96 103 2012 05-28 (2012) 91 09-07 (2012) 90 101 2011 05-30 (2011) 92 08-08 (2011) 93 69 2010 04-07 (2010) 92 09-25 (2010) 90 170

Updated for 9-10. 9-10....Pt Lookout....6.47.....Massapequa....5.41...Wantagh Mesonet...4.64....Amityville....4.04....Copaigue....4.05

Record moisture instead of heat to go with the near record WAR for September.

With the exception of the super El Niño in 15-16 and March 18, the anomalous NEPAC Ridge has told the story of the winter. 13-14 and 14-15 were cold and snowy as the ridge set up over NW Canada. 16-17 and 17-18 were warm and snowy as the ridge location pulled back to the Aleutians. The last 2 winters were warm and nearly snowless as the ridge locked in just north of Hawaii. It’s no coincidence that my favorite snowstorms since 12-13 were in January 16 and March 18 as we finally got a -NAO/-AO pattern.

South Shore coastal sections missed out on the heaviest of the March snows in 2019. So they had two consecutive well below normal snowfall seasons. But they also did much better than the NYC area from 2013 to 2018. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 2020-04-30 6.8 1 2019-04-30 12.8 0 2018-04-30 65.9 0 2017-04-30 39.3 0 2016-04-30 41.4 0 2015-04-30 63.7 0 2014-04-30 63.7 0 2013-04-30 46.9 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 2020-04-30 4.8 1 2019-04-30 20.5 0 2018-04-30 40.9 0 2017-04-30 30.2 0 2016-04-30 32.8 0 2015-04-30 50.3 0 2014-04-30 57.4 0 2013-04-30 26.1 0

The bar is set pretty low. This was the first time that NYC had two consecutive met winters (DJF) under 5”. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 1997-1998 0.5 0 2 1918-1919 1.1 0 3 1972-1973 2.6 0 4 1931-1932 2.7 0 5 1991-1992 3.2 0 6 2001-2002 3.5 0 7 2018-2019 3.7 0 8 2011-2012 4.5 0 9 2019-2020 4.8 0 10 1989-1990 5.0 0

The dust bowl was a localized rather than global event. The heat and drought were amplified by the poor land use practices which lead to the extreme soil erosion. The modern localized summer cooler high temperatures in the corn belt are also a result of farming practices. https://www.journals.uchicago.edu/doi/10.1086/383102 Abstract We provide a new and more complete analysis of the origins of the Dust Bowl of the 1930s, one of the most severe environmental crises in North America in the twentieth century. Severe drought and wind erosion hit the Great Plains in 1930 and lasted through 1940. There were similar droughts in the 1950s and 1970s, but no comparable level of wind erosion. We explain why. The prevalence of small farms in the 1930s limited private solutions for controlling the downwind externalities associated with wind erosion. Drifting sand from unprotected fields damaged neighboring farms. Small farmers cultivated more of their land and were less likely to invest in erosion control than larger farmers. Soil conservation districts, established by the government after 1937, helped coordinate erosion control. This “unitized” solution for collective action is similar to that used in other natural resource/environmental settings. https://www.sciencemag.org/news/2018/02/america-s-corn-belt-making-its-own-weather The Great Plains of the central United States—the Corn Belt—is one of the most fertile regions on Earth, producing more than 10 billion bushels of corn each year. It’s also home to some mysterious weather: Whereas the rest of the world has warmed, the region’s summer temperatures have dropped as much as a full degree Celsius, and rainfall has increased up to 35%, the largest spike anywhere in the world. The culprit, according to a new study, isn’t greenhouse gas emissions or sea surface temperature—it’s the corn itself. https://news.wisc.edu/irrigated-farming-in-wisconsins-central-sands-cools-the-regions-climate/ New research finds that irrigated farms within Wisconsin’s vegetable-growing Central Sands region significantly cool the local climate compared to nearby rain-fed farms or forests. Irrigation dropped maximum temperatures by one to three degrees Fahrenheit on average while increasing minimum temperatures up to four degrees compared to unirrigated farms or forests. In all, irrigated farms experienced a three- to seven-degree smaller range in daily temperatures compared to other land uses. These effects persisted throughout the year.

This is a great example of what high enough snowfall rates can do.

It’s easy to lose track of all the new extremes in recent years.

Another warmer than average start to September across the area. The first week came in at +2.3 to +4.1. EWR...+2.7 NYC...+2.3 LGA....+4.1 JFK....+2.5 ISP.....+3.8 BDR...+4.1

More record breaking 500 mb heights.

We had several more 70° minimums since the start of September. So our local sites are still moving up on the list. We could add a few more this week as the higher dew points return. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Min Temperature >= 70 Missing Count 1 1973 62 0 2 2011 59 0 3 2005 58 0 4 2010 57 0 5 2020 55 116 - 1993 55 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Min Temperature >= 70 Missing Count 1 1906 61 0 2 2005 60 0 3 2020 57 116 4 2015 56 0 5 2018 55 0 - 2010 55 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Min Temperature >= 70 Missing Count 1 2018 78 0 2 2005 77 0 3 2016 73 0 4 2020 71 116 - 2012 71 0 5 2015 69 0 - 2010 69 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Min Temperature >= 70 Missing Count 1 2016 55 0 2 2015 53 0 3 2010 51 0 4 2018 49 0 5 2020 48 116 - 2012 48 0 - 1983 48 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Min Temperature >= 70 Missing Count 1 2018 41 0 2 2010 36 0 - 1980 36 0 3 2020 35 116 - 2016 35 0 4 2013 34 0 - 1999 34 0

First time since 2012 that the 5 day NSIDC extent dropped below 4 million sq km. Also the first 5 year period with 3 years below 4.2 million sq km. 9-6-20.......3.928 September 5-day date 3.387 2012-09-17 4.155 2007-09-18 4.165 2016-09-10 4.192 2019-09-18

Plenty of onshore flow coming up with high pressure to our north and east. So no 90° potential for the foreseeable future. The last time Newark didn’t reach 90° in September was 2011 and 2012 for LGA.

A recent study was able to determine just how extreme the Bering wintertime sea ice low in 2018 was.

It would be really odd if LGA didn’t have another 90° day this year. LGA never reached 30 days before without any 90° days in the spring or fall. LGA is currently in 4th place with 34 days reaching 90°. LGA finished JJA with the 2nd highest number of 90° days behind 2010. Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Aug Sep Oct Season 2010 1 2 12 18 11 4 0 48 2018 0 4 4 10 16 4 0 38 2002 2 0 5 14 13 1 0 35 2020 0 0 5 19 10 0 M 34 1991 0 4 9 10 9 2 0 34 2016 0 3 1 15 10 3 0 32 1983 0 0 5 11 8 7 0 31 2005 0 0 7 10 10 3 0 30 1953 0 1 7 10 9 3 0 30 Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season 2010 12 18 11 41 2020 5 19 10 34

According to Brian B, the US record for earliest measurable snowfall after a 100° was 5 days at Rapid City, SD in September 2000. So Denver could potentially see their latest 100° and then one of their earliest measurable snowfalls. 2000-09-17 101 53 77.0 16.8 0 12 T 0.0 0 2000-09-18 93 64 78.5 18.8 0 14 T 0.0 0 2000-09-19 65 48 56.5 -2.7 8 0 0.04 0.0 0 2000-09-20 61 43 52.0 -6.7 13 0 0.00 0.0 0 2000-09-21 66 41 53.5 -4.8 11 0 0.00 0.0 0 2000-09-22 46 34 40.0 -17.8 25 0 0.27 0.5 0 First/Last Summary for Denver Area, CO (ThreadEx) Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value Last Value Difference 2019 07-19 (2019) 101 09-02 (2019) 100 44 2002 08-16 (2002) 100 08-16 (2002) 100 0 1962 08-10 (1962) 100 08-14 (1962) 100 3 1876 07-06 (1876) 101 08-12 (1876) 100 36 1969 08-08 (1969) 100 08-08 (1969) 100 0 First/Last Summary for Denver Area, CO (ThreadEx) 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 1961 05-13 (1961) 6.4 09-03 (1961) 4.2 112 1962 04-30 (1962) 0.1 09-08 (1962) 0.7 130 1974 04-29 (1974) 0.2 09-12 (1974) 1.8 135 1989 04-30 (1989) 3.7 09-12 (1989) 2.3 134 1993 04-24 (1993) 1.0 09-13 (1993) 5.4 141 1971 04-22 (1971) 4.5 09-16 (1971) 2.7 146

Looks like we will experience near record 500 mb heights for September. But the high will be to our NE with onshore flow.

Yeah, the number of new weather extremes since around 2010 has almost become too numerous to keep track of. Don, thanks for those stats. I guess our version of that near sea level would be February 8th- 9th, 2017. ISP 2017-02-08 62 39 50.5 18.8 14 0 T 0.0 0 2017-02-09 42 18 30.0 -1.8 35 0 1.30 14.3 1