July 2025 Discussion-OBS - seasonable summer variability

[Santa Claus]

fire towards watchung

[SACRUS]

Highs:

EWR: 87
JFK: 87
ACY: 86
TEB: 85
PHL: 85
New Brnswck: 84
LGA: 84
BLM: 83
ISP: 83
NYC: 83
TTN: 82

[SACRUS]

[steve392]

WOW, what an incredible morning coming to work.  60 degree's in Mahwah currently.

[ForestHillWx]

Back to back morning lows of 57/58; very refreshing from the humidity of late. 

[donsutherland1]

Another look at Central Park's summer temperature issue:

During 1970-1995, there were 5.4 days per summer when Central Park's high temperature was 1° or more cooler than the cooler high at JFK Airport and LaGuardia Airport.

During 1996-2024, that figure was 22.8 days.

Since 2000, that figure has averaged 24.0 days.

The change in those averages are even more dramatic for days when Central Park had a high temperature that was at least 2° cooler than the cooler high at JFK Airport or LaGuardia Airport:

1970-1995: 1.3 days per summer

1996-2024: 11.1 days per summer

2000-2024: 12.2 days per summer

Not all of this change has to do with the trees, but most of it does. One has seen smaller changes in the same direction for January 1-March 31 (no foliage) and October 1-December 31 (low foliage). However, the summer (full foliage) change is biggest.

Change in Days with Highs 1° or More Cooler than the Cooler High at JFK Airport and LaGuardia Airport:

1996-2024 vs. 1970-1995: January-March: +93%; June-August: +322%; October-December: +122%

Change in Days with Highs 2° or More Cooler than the Cooler High at JFK Airport and LaGuardia Airport:

1996-2024 vs. 1970-1995: January-March: +59%; June-August: +754%; October-December: +135%

[SACRUS]

66 /64 off a low of 59.  Another amazing beach day mid 80s to low 90s in the hot spots.  Hotter tomorrow and monday with upper 80s low to mid 90s in the hot spots., although clouds from the tropical storm Chantal along the southeast  could get in the way on monday.    Watch any tropical impacts monday evening - tuesday otherwise Warm - hot / humid overall as the area is caught under the ridge with somewhat extra variable forecast pattern through mid month which should yield wetter - frequent storms and persistent onshore component.   Hotter in the long range as ridge pushes heights and stronger heat expands north and east.

[SACRUS]

 

Records:

Highs:

EWR: 103 (1999)
NYC: 101 (1999)
LGA: 100 (1999)
JFK: 102 (1999)
New Brnswck: 100 (1999)


Lows:

EWR: 54 (1979)
NYC: 53 (1979)
LGA: 56 (1979)
JFK: 56 (1979)
New Brnswck: 47 (1909)


Historical:

1643: A violent windstorm hit the Plymouth Colony. The "sudden gust" downed trees and killed one Native American. This may have been the first documented American tornado or microburst. (Ref. Wilson Wx. History)

1816: In parts of New England and the Middle Atlantic, crop damage was severe and fruit trees were killed. In PA ice was found the thickness of window glass.  In Savannah, Georgia the temperature dropped into the 40's on July 4th.  (p. 33 Washington Weather Book 2002 by Ambrose, Henry, Weiss)

1882: A trace of snow was observed at Newton, NJ and other locations in the northeast. (Ref. Wilson Wx. History)

1891 - Sixteen horses were killed by hail, and many more have to be put to death due to injuries from a hailstorm at Rapid City, SD. (The Weather Channel)

1900 - A spectacular three day fire began when a bolt of lightning struck a refinery in Bayonne NJ. (David Ludlum)

 

1905: Washington Weather Bureau Office had 2.77 inches rain in one hour, 3.33 inches in two hours and 4.01 inches in 12 hours. The storm total was 4.64 inches in Baltimore, MD  (Ref. Washington Weather Records - KDCA)

1916 - A hurricane produced 82 mph winds, an 11.6 foot tide, and a barometric pressure of 28.92 inches at Mobile, AL. (David Ludlum)

1936: South Dakota recorded its hottest temperature ever with a reading of 120° at Gannvalley. This same day Sioux Falls reached 109°, their second hottest temperature on record. Three of the 4 hottest days on record in Sioux Falls occurred during the Dust Bowl summer of 1936. (Ref. Lowest and Highest Temperatures for the 50 States)
 

1937 - The temperature at Medicine Lake, MT, soared to 117 degrees to establish a state record. (Sandra and TI Richard Sanders - 1987)

1937 - Midale and Yellow Grass in Saskatchewan hit 113 degrees to establish an all-time record high for Canada that same day. (The Weather Channel)


1967: Canadian high pressure continued to bring record lows to parts of the upper Midwest. Daily record lows included: Duluth, MN: 36°, Rochester, MN: 42°, Rockford, IL: 43°, Asheville, NC: 46°, Bristol, TN: 48°, Richmond, VA: 52°, Knoxville, TN: 54°, Wallops Island, VA: 56°, Charlotte, NC: 57 °F.  (Ref. Wilson Wx. History)

1970: The morning low at Death Valley, CA was 103 degrees and the high that afternoon was 120 degrees. (The Weather Channel)

1972: Temperatures fell to record lows in the upper 30s and lower 40s across the Great Lakes region. The 37° at Lansing, MI was their coldest July reading of the 20th century. Other daily records included: Alpena, MI: 37°, Casper, WY: 38°, Sioux Falls, SD: 39°, Ste. St. Marie, MI: 39°, Huron, SD: 40°, Madison, WI: 40°, North Platte, NE: 42°, Topeka, KS: 43 °F.(Ref. Additional Temperatures Listed On This Link)
 

1970 - The morning low at Death Valley CA was 103 degrees, and the high that afternoon was 120 degrees. (The Weather Channel)

1974: Connecticut--A line of thunderstorms moved southeastward across the state. Lightning caused two deaths, one at Brookfield in Fairfield County and one at Bloomfield in Harford County.  New Jersey--A line of thunderstorms moved eastward across the state in the afternoon. One man in Trenton was killed by lightning. New York City--A thunderstorm passed northeastward across the south and central sections of the city. Lightning struck three girls in Central Park, killing one and injuring two. Wilmington, Del.--A mother was killed by lightning while standing on her porch. (Ref. Lightning-The Underrated Killer.pdf)

1980: The “More Trees Down” started in western Iowa and tracked eastward affecting several states along its past before dissipating in eastern Virginia.

1987 - Severe thunderstorms raked south central Kansas for the second morning in a row. Thunderstorm winds again gusted to 80 mph at Clearwater, and in the Wichita area reached 100 mph. Twenty-five persons were injured at a trailer park at El Dorado Lake. (The National Weather Summary) (Storm Data)

1988 - Afternoon and evening thunderstorms spawned eleven tornadoes in Montana and three in North Dakota. Baseball size hail was reported at Shonkin, MT, and wind gusts to 85 mph were reported south of Fordville, ND. Twenty cities in the north central U.S. reported record high temperatures for the date, including Fargo ND with a reading of 106 degrees. Muskegon, MI, equalled their July record with a high of 95 degrees. (The National Weather Summary) (Storm Data)

1989 - Moisture from what once was Tropical Storm Allison triggered thunderstorms over the Middle Atlantic Coast Region, which deluged Wilmington, DE, with a record 6.83 inches of rain in 24 hours, including 6.37 inches in just six hours. Up to ten inches of rain was reported at Claymont, northeast of Wilmington. July 1989 was thus the wettest month in seventy years for Wilmington, with a total of 12.63 inches of rain. Alamosa CO reported an all-time record high of 94 degrees, and Pierre, SD, hit 113 degrees. (The National Weather Summary) (Storm Data)


1994: Thunderstorms, mainly packing high winds, erupted over north central Nebraska into south central South Dakota. As the storms moved east, 60 to 70 mph winds were common across the tri-state area. In Iowa, 65 mph winds were clocked in Monona County wrecking havoc with power lines. In Crawford County, 80 mph winds broke windows out of houses and caused some barn damage southwest of Charter Oak. Winds of 75 mph also swept into Sioux County causing significant damage to buildings on a farmstead near Hawarden. (Ref. Wilson Wx. History)

1999: July 4th and 5th ........"The Boundary Waters-Canadian Derecho" States that were affected --- ....ND, MN, ON, QB, NH, VT, ME
(Ref. For More Information)

2001: International Falls, MN set a record low with 34°.  2.20 inches of rain fell in just 15 minutes at Pine Mountain, CA in Kern County.
(Ref. Wilson Wx. History)

2003: Rockford, Illinois: An early morning band of severe thunderstorms blows across Northern Illinois with peak winds reported at 104 mph. Over 80,000 people are without power for various durations after the storm. (Ref. WxDoctor)

2004: For the second day in a row a derecho, a line of thunderstorms that produces widespread damaging winds, tracked from southeast Kansas into central Missouri across the Lake of the Ozarks region. (Ref. Wilson Wx. History)

2008: A streak of 26 consecutive days of 90°+ heat beginning on June 13th ended on this date at Denver, CO, shattering the previous record of 18 consecutive days established in 1874 & 1901. (Ref. Wilson Wx. History)

[bluewave]

1 hour ago, donsutherland1 said:

During 1970-1995, there were 5.4 days per summer when Central Park's high temperature was 1° or more cooler than the cooler high at JFK Airport and LaGuardia Airport.

During 1996-2024, that figure was 22.8 days.

Since 2000, that figure has averaged 24.0 days.

This was the reason that the NWS didn’t like to substitute readings at LGA back in the 1970s when the NWS equipment was out of service. Before the tree growth issue in the 1970s, LGA ran cooler than NYC did. So the NWS recognized that an open area of Central Park in the middle of Manhattan was a warmer part of NYC for summer high temperatures than right on the bay in Northern Queens. Central Park is our one ASOS in or around NYC which is the furthest distance from the water and local cooling breezes. So my estimate is that the placement of the ASOS under the trees has resulted in nearly 10 fewer 90° days reaching annually then they would be getting if the equipment was sited the same way prior to the 1990s. 

Annual 90° day counts for EWR, NYC and LGA during the 1961-1990 era prior to the ASOS being placed under the trees in the deep shade.

EWR…..23 days

NYC…..18 days

LGA…..14 days

Annual 90° day counts for EWR, NYC, and LGA during the most recent 15 year period of maximum tree growth and summer warming from 2010 to 2024.  12 out of the last 15 summers warmer to record warm across the region. 
 

EWR…..33 days for a 43% increase over 1961-1990 averages 

NYC…..19 days for only a 5% increase over 1961-1990 averages

LGA…..25 days for a 78% increase over 1961-1990 averages 

The actual number of 90° days Central Park would be getting if the ASOS wasn’t under the trees would be around 28 a year. I arrived at this number by averaging the 43% increase at LGA and 78% at LGA. The average number was a 60% increase or 10 days more up to 28 days from 18 days. So the 5% increase from 1961-1990 should actually be 60%. So an annual undercount of 55% for 90° days if the ASOS was in a grassy clearing like the Great Lawn rather than beneath a densely wooded area of Central Park next to the castle.

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

 

[donsutherland1]

2 minutes ago, bluewave said:

This was the reason that the NWS didn’t like to substitute readings at LGA back in the 1970s when the NWS equipment was out of service. Before the tree growth issue in the 1970s, LGA ran cooler than NYC did. So the NWS recognized that an open area of Central Park in the middle of Manhattan was a warmer part of NYC for summer high temperatures than right on the bay in Northern Queens. Central Park is our one ASOS in or around NYC which is the furthest distance from the water and local cooling breezes. So my estimate is that the placement of the ASOS under the trees has resulted in nearly 10 fewer 90° days reaching annually then they would be getting if the equipment was sited the same way prior to the 1990s. 

Annual 90° day counts for EWR, NYC and LGA during the 1961-1990 era prior to the ASOS being placed under the trees in the deep shade.

EWR…..23 days

NYC…..18 days

LGA…..14 days

Annual 90° day counts for EWR, NYC, and LGA during the most recent 15 year period of maximum tree growth and summer warming from 2010 to 2024.  12 out of the last 15 summers warmer to record warm across the region. 
 

EWR…..33 days for a 43% increase over 1961-1990 averages 

NYC…..19 days for only a 5% increase over 1961-1990 averages

LGA…..25 days for a 78% increase over 1961-1990 averages 

The actual number of 90° days Central Park would be getting if the ASOS wasn’t under the trees would be around 28 a year. I arrived at this number by averaging the 43% increase at LGA and 78% at LGA. The average number was a 60% increase or 10 days more up to 28 days from 18 days. So the 5% increase from 1961-1990 should actually be 60%. So an annual undercount of 55% for 90° days if the ASOS wasn’t under in a grassy clearing like the Great Lawn rather than beneath a densely wooded area of Central Park.

 

 

 

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

 

I agree. It is disappointing that the situation at Central Park has been neglected. The data no longer reliably reflects summer conditions in Manhattan. No matter how the data is examined, one sees an unmistakable impact during the summer or full foliage months.

[TriPol]

Chantal is looking interesting for Monday/Tuesday. Very interesting.

[Sundog]

46 minutes ago, donsutherland1 said:

I agree. It is disappointing that the situation at Central Park has been neglected. The data no longer reliably reflects summer conditions in Manhattan. No matter how the data is examined, one sees an unmistakable impact during the summer or full foliage months.

All they have to do is chop back enough to where the shadows don't fall on the station post leaf out. 

The station right now has basically no clearance around it:

I have no hope that it will ever have 100 feet of clear land around it, but at least cut back enough to where the shadows aren't all over the station. 

[bluewave]

The Euro brings in Chantal’s remnants Monday into Tuesday. 2.00-2.50 PWATS and mid 70s dewpoints for heavy rain potential. Will probably have to within the SPC HREF range to guess the peak amounts. 

 

[FPizz]

56 this morning 

[psv88]

61. Beautiful morning 

[LibertyBell]

16 hours ago, Roger Smith said:

If there was no calendar and every 31-day interval was equally valid, these would be the top 50 warmest "months" for NYC ... just counting the warmest instance in any given year unless in theory two non-overlapping 31 day intervals qualified, 1988 and 2002 were the only examples (otherwise, they do not quite make list, the second instance in 1931 ranks 51st) ... a number of secondary peaks more than halfway through these qualifying spells do not count for ranking separately, there needs to be total separation of the intervals for ranking ... you could rank more if you accepted two sets that don't include the actual peak ... it's pretty similar to the list of warmest calendar months but the averages are generally higher and it's interesting that no annual peak happens to coincide with a calendar month.

I list them by mean maximum to reduce the interference of the growing heat island, mean daily would be skewed more to recent examples. 

 

Rank Year __ Interval (31d) _________ Mean max (F)

 1. 1966 June 20 to July 20 ___________91.97

 2. 1993 July 5 to Aug 4 ______________91.61

 3. 1999 July 3 or 4 to Aug 2 or 3 ____ 90.94

 4. 1955 July 8 to Aug 7 ______________ 90.90

 5. 1944 July 22 to Aug 21 ___________ 90.84

 6. 1980 July 14 to Aug 13 ____________ 90.71

t7. 1988A July 16 to Aug 15 ___________ 90.29

t7. 2010 June 27 to July 27 __________ 90.29 (or July 3 to Aug 2 was also 90.29)

 9. 2005 July 15 to Aug 14 ___________ 89.87

10. 2011 July 4 to Aug 3 _____________ 89.84

11. 1983 July 11 to Aug 10 ____________ 89.71

12. 1952 June 24 to July 24 _________ 89.35

t13. 1977 July 13 to Aug 12 ___________ 89.29

t13. 1995 July 13 to Aug 12 ___________ 89.29

t15. 1876 June 23 to July 23 __________ 89.26

t15. 1991 June 24 to July 24 __________ 89.26

t15. 2006 July 11 to Aug 10 ____________89.26

18. 1949 July 13 to Aug 12 ____________ 89.13 __ a non-overlapping 31d interval June 11 to July 11 was 86.74

19. 1953 June 20 to July 20 __________ 88.90 __ non-overlapping 31d intervals Aug 8 (or 10) to Sep 7 (or 9) 87.00

20. 2002 Jul 20 or 22 to Aug 19 or 21_ 88.87 __ non-overlapping 31d interval June 20 or 21 to July 20 or 21 was 87.10

21. 2022 July 12 to Aug 11 ____________ 88.77  (also 87.19 Aug 2 to Sep 1, partial overlap, secondary peak)

22. 1943 July 11 to Aug 10 ____________ 88.42

23. 2012 Jun 27 or 28 to Jul 27 or 28_ 88.32

24. 2024 June 18 to July 18 __________ 88.23  (also 88.19 July 4 to Aug 3, partial overlap, secondary peak)

t25. 1979 July 11 to Aug 10_____________88.19

t25. 2015 July 19 to Aug 18____________88.19  (also 87.87 Aug 10 to Sep 9, partial overlap, secondary peak)

27. 1994 June 14 to July 14 ___________ 88.16 (also 87.94 July 5 to Aug 4, partial overlap, secondary peak)

28. 1957 July 4 to Aug 3 ______________ 88.10

29. 2016 July 16 to Aug 15 ____________ 88.06

30. 2013 June 23 to July 23 __________ 87.97

31. 1959 Aug 10 to Sep 9 _____________ 87.87

t32. 1938 July 25 to Aug 24 ___________87.74

t32. 1939 July 24 to Aug 23 __________ 87.74

34. 2020 July 2 to Aug 1 _____________ 87.68

t35. 1901 June 24 to July 24 __________ 87.61

t35. 1981 July 7 to Aug 6 ______________ 87.61

t35. 1987 July 9 to Aug 8 _____________ 87.61

38. 1872 June 18 to July 18 ___________ 87.55

t39. 1936 July 5 to Aug 4 ______________87.52

t39. 1988 B June 12 to July 12 _________87.52

t41. 1954 July 9 to Aug 8 _____________ 87.29

t41. 1970 July 23 to Aug 22 __________ 87.29

t41. 1982 July 6 to Aug 5 _____________ 87.29

44. 1968 July 12 to Aug 11 ___________ 87.23

45. 1930 July 11 to Aug 10 ____________ 87.19

t46. 1931 July 11 to Aug 10 _____________87.16

t46. 2019 July 2 to Aug 1 ______________ 87.16

t48. 2002 B Jun 20or21 to Jul 20or21 __87.10

t48. 2008 July 8 to Aug 7 _____________ 87.10

50. 1940 July 15 to Aug 14 ____________ 87.06

51. 1931 B Aug 8 to Sep 7 _____________ 87.00

52. 1937 July 10 to Aug 9 _____________ 86.97

t53. 1870. July 11 to Aug 10 ____________86.90

t53. 1934. June 21, 22 to July 21, 22___86.90

t55. 1900 June 25 to July 25 ___________86.84

t55. 1961 Aug 7 to Sep 6 _______________86.84

t55. 1973 Aug 5 to Sep 4 ______________ 86.84

58. (1949) June 11 to July 11 ___________ 86.74

59. 1918 July 15 to Aug 14 _____________ 86.71

t60. 1885 July 6 to Aug 5 ______________ 86.68

t60. 1971 June 16 to July 15 ____________ 86.68

(62. 1887 June 30 to July 30 _________ 86.65)

(63. 1997 June 19 to July 19 ___________ 86.61)

(64. 2001 July 31 to Aug 30 ___________ 86.58)

(65. 1974 July 2 to Aug 1 ______________ 86.55)

(66. 1896 July 15 to Aug 14 ___________ 86.48)

(67. 1932 July 10 to Aug 9 ____________ 86.48)

(68. 1990 July 18 to Aug 17 ___________ 86.42)

(t69. 1911 July 2 to Aug 1 _______________86.39)

(t69. 1917 July 13 or 16 to Aug 12, 15) __ 86.39)

(t69. 1969 Aug 3 to Sep 2 _____________ 86.39)

(t69. 2023 June 29 to July 29 ________ 86.39)

(73. 1963 July 13 to Aug 12 ___________ 86.35)

(t74. 1878 June 26 to July 26 __________86.32)

(t74. 1908 June 20 to July 20 _________ 86.32)

(76. 1941 July 10 to Aug 9 _____________86.29)

(77. 1972 July 10 to Aug 9 ____________ 86.23)

(78. 1935 July 5 to Aug 4 _____________ 86.19)

(79. 1933 July 6 to Aug 5 _____________ 86.10)

(80. 1921 July 2 to Aug 1 ______________ 86.03)

_________________________

As 1953, 1988, 2002 have two qualifying separate intervals, 63 are ranked for 60 leading years. 

All near misses, some that had well known heat waves, are added in the 86-87 range.

This is basically the top half of the years, the worst three for lack of heat are 1869 (peak 79.29), 1889 (81.61) and 2000 (81.71), 4th was 1871 (81.81).  

The usual suspects are in the top 20, the summers I always talk about lol. Question though, why are we using 31 not 30? A month is scientifically speaking, the amount of time it takes for the moon to revolve around the earth and that averages out to 30 days (it's really 29.53 but we can round that to 30.)  

 

1. 1966 June 20 to July 20 ___________91.97

 2. 1993 July 5 to Aug 4 ______________91.61

 3. 1999 July 3 or 4 to Aug 2 or 3 ____ 90.94

 4. 1955 July 8 to Aug 7 ______________ 90.90

 5. 1944 July 22 to Aug 21 ___________ 90.84

 6. 1980 July 14 to Aug 13 ____________ 90.71

t7. 1988A July 16 to Aug 15 ___________ 90.29

t7. 2010 June 27 to July 27 __________ 90.29 (or July 3 to Aug 2 was also 90.29)

 9. 2005 July 15 to Aug 14 ___________ 89.87

10. 2011 July 4 to Aug 3 _____________ 89.84

11. 1983 July 11 to Aug 10 ____________ 89.71

12. 1952 June 24 to July 24 _________ 89.35

t13. 1977 July 13 to Aug 12 ___________ 89.29

t13. 1995 July 13 to Aug 12 ___________ 89.29

t15. 1876 June 23 to July 23 __________ 89.26

t15. 1991 June 24 to July 24 __________ 89.26

t15. 2006 July 11 to Aug 10 ____________89.26

18. 1949 July 13 to Aug 12 ____________ 89.13 __ a non-overlapping 31d interval June 11 to July 11 was 86.74

19. 1953 June 20 to July 20 __________ 88.90 __ non-overlapping 31d intervals Aug 8 (or 10) to Sep 7 (or 9) 87.00

20. 2002 Jul 20 or 22 to Aug 19 or 21_ 88.87 __ non-overlapping 31d interval June 20 or 21 to July 20 or 21 was 87.10

[LibertyBell]

28 minutes ago, bluewave said:

The Euro brings in Chantal’s remnants Monday into Tuesday. 2.00-2.50 PWATS and mid 70s dewpoints for heavy rain potential. Will probably have to within the SPC HREF range to guess the peak amounts. 

 

This might be the days of rain I saw on the forecast yesterday.  Sunday might be our last good day for awhile.

[LibertyBell]

47 minutes ago, Sundog said:

All they have to do is chop back enough to where the shadows don't fall on the station post leaf out. 

The station right now has basically no clearance around it:

I have no hope that it will ever have 100 feet of clear land around it, but at least cut back enough to where the shadows aren't all over the station. 

Just get the equipment out of Central Park and the problem is solved.  Government needs to step in since NWS won't do a thing.

 

[LibertyBell]

1 hour ago, bluewave said:

This was the reason that the NWS didn’t like to substitute readings at LGA back in the 1970s when the NWS equipment was out of service. Before the tree growth issue in the 1970s, LGA ran cooler than NYC did. So the NWS recognized that an open area of Central Park in the middle of Manhattan was a warmer part of NYC for summer high temperatures than right on the bay in Northern Queens. Central Park is our one ASOS in or around NYC which is the furthest distance from the water and local cooling breezes. So my estimate is that the placement of the ASOS under the trees has resulted in nearly 10 fewer 90° days reaching annually then they would be getting if the equipment was sited the same way prior to the 1990s. 

Annual 90° day counts for EWR, NYC and LGA during the 1961-1990 era prior to the ASOS being placed under the trees in the deep shade.

EWR…..23 days

NYC…..18 days

LGA…..14 days

Annual 90° day counts for EWR, NYC, and LGA during the most recent 15 year period of maximum tree growth and summer warming from 2010 to 2024.  12 out of the last 15 summers warmer to record warm across the region. 
 

EWR…..33 days for a 43% increase over 1961-1990 averages 

NYC…..19 days for only a 5% increase over 1961-1990 averages

LGA…..25 days for a 78% increase over 1961-1990 averages 

The actual number of 90° days Central Park would be getting if the ASOS wasn’t under the trees would be around 28 a year. I arrived at this number by averaging the 43% increase at LGA and 78% at LGA. The average number was a 60% increase or 10 days more up to 28 days from 18 days. So the 5% increase from 1961-1990 should actually be 60%. So an annual undercount of 55% for 90° days if the ASOS was in a grassy clearing like the Great Lawn rather than beneath a densely wooded area of Central Park next to the castle.

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

 

But we should have local cooling breezes because New York City exists on islands (besides The Bronx of course.)  I just don't believe that a park could ever be representative of urban conditions and the equipment should NEVER have been in a park to begin with.  We have a heliport in lower Manhattan, that's where it should be.  LGA is also hotter than most of the area because of how densely packed that region is and its overnight lows are always elevated compared to both JFK and Central Park.  For Manhattan urban area purposes the equipment in Central Park needs to be taken out of the park and relocated to the heliport.

 

[LibertyBell]

1 hour ago, bluewave said:

This was the reason that the NWS didn’t like to substitute readings at LGA back in the 1970s when the NWS equipment was out of service. Before the tree growth issue in the 1970s, LGA ran cooler than NYC did. So the NWS recognized that an open area of Central Park in the middle of Manhattan was a warmer part of NYC for summer high temperatures than right on the bay in Northern Queens. Central Park is our one ASOS in or around NYC which is the furthest distance from the water and local cooling breezes. So my estimate is that the placement of the ASOS under the trees has resulted in nearly 10 fewer 90° days reaching annually then they would be getting if the equipment was sited the same way prior to the 1990s. 

Annual 90° day counts for EWR, NYC and LGA during the 1961-1990 era prior to the ASOS being placed under the trees in the deep shade.

EWR…..23 days

NYC…..18 days

LGA…..14 days

Annual 90° day counts for EWR, NYC, and LGA during the most recent 15 year period of maximum tree growth and summer warming from 2010 to 2024.  12 out of the last 15 summers warmer to record warm across the region. 
 

EWR…..33 days for a 43% increase over 1961-1990 averages 

NYC…..19 days for only a 5% increase over 1961-1990 averages

LGA…..25 days for a 78% increase over 1961-1990 averages 

The actual number of 90° days Central Park would be getting if the ASOS wasn’t under the trees would be around 28 a year. I arrived at this number by averaging the 43% increase at LGA and 78% at LGA. The average number was a 60% increase or 10 days more up to 28 days from 18 days. So the 5% increase from 1961-1990 should actually be 60%. So an annual undercount of 55% for 90° days if the ASOS was in a grassy clearing like the Great Lawn rather than beneath a densely wooded area of Central Park next to the castle.

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

 

If you go by decades rather than 30 year periods, our number of 90 degree days peaked during the 90s.  You can run the numbers for all the locations you mentioned and also JFK.  We had multiple historically hot summers during the 90s (91,93,95,99) and we have not had that kind of sustained heat since then (with the exception of 2010.)

 

[LibertyBell]

2 hours ago, SACRUS said:

 

Records:

Highs:

EWR: 103 (1999)
NYC: 101 (1999)
LGA: 100 (1999)
JFK: 102 (1999)
New Brnswck: 100 (1999)


Lows:

EWR: 54 (1979)
NYC: 53 (1979)
LGA: 56 (1979)
JFK: 56 (1979)
New Brnswck: 47 (1909)


Historical:

1643: A violent windstorm hit the Plymouth Colony. The "sudden gust" downed trees and killed one Native American. This may have been the first documented American tornado or microburst. (Ref. Wilson Wx. History)

1816: In parts of New England and the Middle Atlantic, crop damage was severe and fruit trees were killed. In PA ice was found the thickness of window glass.  In Savannah, Georgia the temperature dropped into the 40's on July 4th.  (p. 33 Washington Weather Book 2002 by Ambrose, Henry, Weiss)

1882: A trace of snow was observed at Newton, NJ and other locations in the northeast. (Ref. Wilson Wx. History)

1891 - Sixteen horses were killed by hail, and many more have to be put to death due to injuries from a hailstorm at Rapid City, SD. (The Weather Channel)

1900 - A spectacular three day fire began when a bolt of lightning struck a refinery in Bayonne NJ. (David Ludlum)

 

1905: Washington Weather Bureau Office had 2.77 inches rain in one hour, 3.33 inches in two hours and 4.01 inches in 12 hours. The storm total was 4.64 inches in Baltimore, MD  (Ref. Washington Weather Records - KDCA)

1916 - A hurricane produced 82 mph winds, an 11.6 foot tide, and a barometric pressure of 28.92 inches at Mobile, AL. (David Ludlum)

1936: South Dakota recorded its hottest temperature ever with a reading of 120° at Gannvalley. This same day Sioux Falls reached 109°, their second hottest temperature on record. Three of the 4 hottest days on record in Sioux Falls occurred during the Dust Bowl summer of 1936. (Ref. Lowest and Highest Temperatures for the 50 States)
 

1937 - The temperature at Medicine Lake, MT, soared to 117 degrees to establish a state record. (Sandra and TI Richard Sanders - 1987)

1937 - Midale and Yellow Grass in Saskatchewan hit 113 degrees to establish an all-time record high for Canada that same day. (The Weather Channel)


1967: Canadian high pressure continued to bring record lows to parts of the upper Midwest. Daily record lows included: Duluth, MN: 36°, Rochester, MN: 42°, Rockford, IL: 43°, Asheville, NC: 46°, Bristol, TN: 48°, Richmond, VA: 52°, Knoxville, TN: 54°, Wallops Island, VA: 56°, Charlotte, NC: 57 °F.  (Ref. Wilson Wx. History)

1970: The morning low at Death Valley, CA was 103 degrees and the high that afternoon was 120 degrees. (The Weather Channel)

1972: Temperatures fell to record lows in the upper 30s and lower 40s across the Great Lakes region. The 37° at Lansing, MI was their coldest July reading of the 20th century. Other daily records included: Alpena, MI: 37°, Casper, WY: 38°, Sioux Falls, SD: 39°, Ste. St. Marie, MI: 39°, Huron, SD: 40°, Madison, WI: 40°, North Platte, NE: 42°, Topeka, KS: 43 °F.(Ref. Additional Temperatures Listed On This Link)
 

1970 - The morning low at Death Valley CA was 103 degrees, and the high that afternoon was 120 degrees. (The Weather Channel)

1974: Connecticut--A line of thunderstorms moved southeastward across the state. Lightning caused two deaths, one at Brookfield in Fairfield County and one at Bloomfield in Harford County.  New Jersey--A line of thunderstorms moved eastward across the state in the afternoon. One man in Trenton was killed by lightning. New York City--A thunderstorm passed northeastward across the south and central sections of the city. Lightning struck three girls in Central Park, killing one and injuring two. Wilmington, Del.--A mother was killed by lightning while standing on her porch. (Ref. Lightning-The Underrated Killer.pdf)

1980: The “More Trees Down” started in western Iowa and tracked eastward affecting several states along its past before dissipating in eastern Virginia.

1987 - Severe thunderstorms raked south central Kansas for the second morning in a row. Thunderstorm winds again gusted to 80 mph at Clearwater, and in the Wichita area reached 100 mph. Twenty-five persons were injured at a trailer park at El Dorado Lake. (The National Weather Summary) (Storm Data)

1988 - Afternoon and evening thunderstorms spawned eleven tornadoes in Montana and three in North Dakota. Baseball size hail was reported at Shonkin, MT, and wind gusts to 85 mph were reported south of Fordville, ND. Twenty cities in the north central U.S. reported record high temperatures for the date, including Fargo ND with a reading of 106 degrees. Muskegon, MI, equalled their July record with a high of 95 degrees. (The National Weather Summary) (Storm Data)

1989 - Moisture from what once was Tropical Storm Allison triggered thunderstorms over the Middle Atlantic Coast Region, which deluged Wilmington, DE, with a record 6.83 inches of rain in 24 hours, including 6.37 inches in just six hours. Up to ten inches of rain was reported at Claymont, northeast of Wilmington. July 1989 was thus the wettest month in seventy years for Wilmington, with a total of 12.63 inches of rain. Alamosa CO reported an all-time record high of 94 degrees, and Pierre, SD, hit 113 degrees. (The National Weather Summary) (Storm Data)


1994: Thunderstorms, mainly packing high winds, erupted over north central Nebraska into south central South Dakota. As the storms moved east, 60 to 70 mph winds were common across the tri-state area. In Iowa, 65 mph winds were clocked in Monona County wrecking havoc with power lines. In Crawford County, 80 mph winds broke windows out of houses and caused some barn damage southwest of Charter Oak. Winds of 75 mph also swept into Sioux County causing significant damage to buildings on a farmstead near Hawarden. (Ref. Wilson Wx. History)

1999: July 4th and 5th ........"The Boundary Waters-Canadian Derecho" States that were affected --- ....ND, MN, ON, QB, NH, VT, ME
(Ref. For More Information)

2001: International Falls, MN set a record low with 34°.  2.20 inches of rain fell in just 15 minutes at Pine Mountain, CA in Kern County.
(Ref. Wilson Wx. History)

2003: Rockford, Illinois: An early morning band of severe thunderstorms blows across Northern Illinois with peak winds reported at 104 mph. Over 80,000 people are without power for various durations after the storm. (Ref. WxDoctor)

2004: For the second day in a row a derecho, a line of thunderstorms that produces widespread damaging winds, tracked from southeast Kansas into central Missouri across the Lake of the Ozarks region. (Ref. Wilson Wx. History)

2008: A streak of 26 consecutive days of 90°+ heat beginning on June 13th ended on this date at Denver, CO, shattering the previous record of 18 consecutive days established in 1874 & 1901. (Ref. Wilson Wx. History)

Mighty hot July 1999 just getting started on this date....

 

Records:

Highs:

EWR: 103 (1999)
NYC: 101 (1999)
LGA: 100 (1999)
JFK: 102 (1999)
New Brnswck: 100 (1999)

 

This day ranks with the hottest days ever in our area, when all official reporting stations recorded record highs in the triple digits on the same date!

[LibertyBell]

10 hours ago, SACRUS said:

Highs:

EWR: 87
JFK: 87
ACY: 86
TEB: 85
PHL: 85
New Brnswck: 84
LGA: 84
BLM: 83
ISP: 83
NYC: 83
TTN: 82

nice, EWR and JFK hotter than everyone else and also low humidity and deep blue skies....

 

[bluewave]

9 minutes ago, LibertyBell said:

But we should have local cooling breezes because New York City exists on islands (besides The Bronx of course.)  I just don't believe that a park could ever be representative of urban conditions and the equipment should NEVER have been in a park to begin with.  We have a heliport in lower Manhattan, that's where it should be.  LGA is also hotter than most of the area because of how densely packed that region is and its overnight lows are always elevated compared to both JFK and Central Park.  For Manhattan urban area purposes the equipment in Central Park needs to be taken out of the park and relocated to the heliport.

 

A grassy clearing in Central Park like the Great Lawn is among of the warmest parts of Manhattan Island and NYC.  It’s one of the few spots that gets full sun during the summer. As the midtown streets are often in the shade with the increase in the ultra tall skyscrapers. Plus Central Park has an unusual amount of exposed bedrock which really heats up. This is why Central Park would often have similar temperatures as Newark and sometimes warmer during the summer from the 1930s to around 1980. 

[LibertyBell]

22 hours ago, bluewave said:

Looks like the next warm up in mid-July will be another over the top one leaving room for moisture undercutting the ridge before then.

With the exception of June, this is why our heatwaves are weaker and do not last as long as they did in the 90s and the decades before then.

 

[LibertyBell]

Just now, bluewave said:

A grassy clearing in Central Park like the Great Lawn is among of the warmest parts of Manhattan Island and NYC.  It’s one of the few spots that gets full sun during the summer. As the midtown streets are often in the shade with the increase in the ultra tall skyscrapers. Plus Central Park has an unusual amount of exposed bedrock which really heats up. This is why Central Park would often have similar temperatures as Newark and sometimes warmer during the summer from the 1930s to around 1980. 

This is why I advocate for the heliport (KJRB peaked at 105 in June).  Besides the heliport, we can use rooftop stations.  They would definitely be hotter than the shaded areas you speak of.

 

[LibertyBell]

23 hours ago, bluewave said:

Yeah, unusually cool and wet July 4th following the snowiest winter of the 1970s.

 

Climatological Data for ISLIP-LI MACARTHUR AP, NY - July 1978
Click column heading to sort ascending, click again to sort descending.

1978-07-01	78	58	68.0	-5.5	0	3	0.00	0.0	0
1978-07-02	73	55	64.0	-9.7	1	0	0.00	0.0	0
1978-07-03	70	60	65.0	-8.9	0	0	0.99	0.0	0
1978-07-04	61	56	58.5	-15.6	6	0	1.56	0.0	0

 

Climatological Data for JFK INTERNATIONAL AIRPORT, NY - July 1978
Click column heading to sort ascending, click again to sort descending.

1978-07-01	84	66	75.0	0.3	0	10	0.00	0.0	0
1978-07-02	78	57	67.5	-7.4	0	3	0.00	0.0	0
1978-07-03	71	60	65.5	-9.6	0	1	1.73	0.0	0
1978-07-04	65	60	62.5	-12.7	2	0	0.50	0.0	0

 

Snowfall Data for October 1, 1977 through April 30, 1978
Click column heading to sort ascending, click again to sort descending.

NY	PORT JERVIS	COOP	70.5
NY	PATCHOGUE 2 N	COOP	68.7
NY	ISLIP-LI MACARTHUR AP	WBAN	68.0
CT	DANBURY	COOP	67.0
NY	NY WESTERLEIGH STAT IS	COOP	66.7
NJ	PLAINFIELD	COOP	65.2
NJ	NEWARK LIBERTY INTL AP	WBAN	64.9
NY	MIDDLETOWN 2	COOP	64.7
CT	MOUNT CARMEL	COOP	64.1
NJ	CHARLOTTEBURG RESERVOIR	COOP	62.3
NY	DOBBS FERRY-ARDSLEY	COOP	61.6
NJ	CRANFORD	COOP	60.7
CT	MIDDLETOWN 4 W	COOP	60.2
NY	WESTCHESTER CO AP	WBAN	59.7
NY	SCARSDALE	COOP	59.6
NY	BRIDGEHAMPTON	COOP	59.1
NJ	GREENWOOD LAKE	COOP	59.0
NY	NEW YORK AVE V BROOKLYN	COOP	58.0
NY	RIVERHEAD RESEARCH FARM	COOP	57.5
NY	YORKTOWN HEIGHTS 1W	COOP	57.1
CT	STAMFORD 5 N	COOP	56.0
NY	MINEOLA	COOP	55.8
NJ	WANAQUE RAYMOND DAM	COOP	55.6
NY	WALDEN 1 ESE	COOP	54.2
CT	IGOR I SIKORSKY MEMORIAL AIRPORT	WBAN	52.7
NY	NEW YORK LAUREL HILL	COOP	51.6
NJ	CANOE BROOK	COOP	51.4
NY	NY CITY CENTRAL PARK	WBAN	50.7
NJ	MIDLAND PARK	COOP	49.1
CT	GROTON	COOP	48.9
NY	JFK INTERNATIONAL AIRPORT	WBAN	48.5
NJ	TETERBORO AIRPORT	WBAN	48.3
NY	SETAUKET STRONG	COOP	46.5
NJ	LITTLE FALLS	COOP	45.6
NY	LAGUARDIA AIRPORT	WBAN	43.5

 

absolutely wild Chris.... and after the historic heatwave we had in July 1977.

[LibertyBell]

19 hours ago, Wannabehippie said:

Different types of root systems on sycamores than oaks would be my guess on why the sycamores survived. Oaks I know have a lateral root system that are not deep. You cut one of those main lateral roots, and you have weakened that entire side. Add in soaking rains, softening the soil, the winds, and you get trees falling like they did in the picture.

 

 

Thats how the roof at my other property was destroyed by falling oak trees, they don't have a deep root system and are vulnerable to microbursts and other strong wind events.

 

[bluewave]

18 minutes ago, LibertyBell said:

This is why I advocate for the heliport (KJRB peaked at 105 in June).  Besides the heliport, we can use rooftop stations.  They would definitely be hotter than the shaded areas you speak of.

 

The heliport gets sea breezes off the NY Harbor. So it’s not really representative of the areas of NYC away from the shore. I would have them decommission the site by the castle since the park conservancy would never allow any of those trees to be cut down.

The one thing I learned over the years is that people love their trees. Back on the South Shore were I used to live there were big disputes which emerged when some trees were going to be removed from my community. Several trees were damaged and were at a risk of falling on some of the houses. I was glad to have them removed. But some residents tried to block the tree removal guys from doing their job. As several fallen weak trees caused property damage prior to the crews arrival.

So if NYC every tried to remove those trees around the ASOS, their would be a big protest. I would give the NYC mesonet the opportunity to pick  a spot Central Park in a clearing to install a new site like below. So no trees would have to be disturbed.

 

 

[LibertyBell]

52 minutes ago, bluewave said:

The heliport gets sea breezes off the NY Harbor. So it’s not really representative of the areas of NYC away from the shore. I would have them decommission the site by the castle since the park conservancy would never allow any of those trees to be cut down.

The one thing I learned over the years is that people love their trees. Back on the South Shore were I used to live there were big disputes which emerged when some trees were going to be removed from my community. Several trees were damaged and were at a risk of falling on some of the houses. I was glad to have them removed. But some residents tried to block the tree removal guys from doing their job. As several fallen weak trees caused property damage prior to the crews arrival.

So if NYC every tried to remove those trees around the ASOS, their would be a big protest. I would give the NYC mesonet the opportunity to pick  a spot Central Park in a clearing to install a new site like below. So no trees would have to be disturbed.

 

 

Did we have less trees in the 40s, 50s and 60s when all those 100+ readings and 7+ day heatwaves were happening (as well as years like 1993 and 1999) or was there overgrowth because of the higher rainfall totals we have now? Maybe it's a combination of both? And more rainfall also means more water retention by the foliage which also makes for a slower temperature rise.

I agree we need to get the equipment out of that area.

We also need to remove some of these trees, I notice we have a lot of parasitic trees that really do not belong here. Tree of *Heaven* being a case in point.

 

 

[LibertyBell]

56 minutes ago, bluewave said:

The heliport gets sea breezes off the NY Harbor. So it’s not really representative of the areas of NYC away from the shore. I would have them decommission the site by the castle since the park conservancy would never allow any of those trees to be cut down.

The one thing I learned over the years is that people love their trees. Back on the South Shore were I used to live there were big disputes which emerged when some trees were going to be removed from my community. Several trees were damaged and were at a risk of falling on some of the houses. I was glad to have them removed. But some residents tried to block the tree removal guys from doing their job. As several fallen weak trees caused property damage prior to the crews arrival.

So if NYC every tried to remove those trees around the ASOS, their would be a big protest. I would give the NYC mesonet the opportunity to pick  a spot Central Park in a clearing to install a new site like below. So no trees would have to be disturbed.

 

 

That's a great idea, if we have a mesonet location in the Park we can actually compare it to the *official* NWS ASOS.....and maybe some corrective factor can be applied to the ASOS (both for temperatures and wind speeds)?