bluewave

Temperatures finally getting back closer to normal this week into next weekend. Looks like a mix of 60s some days and 70s on the warmer days around NYC . The cutoff low stalling to our south will maintain the onshore flow.

I haven’t found any instances of JFK having more 90° days than LGA or EWR. JFK and several Long Island stations beat Central Park in 2006. But we know it’s due to the trees and vegetation artificially cooling the NYC readings .That was a few years after the 2003 news report on the inaccurate NYC temperatures. So this issue has been known for over 20 years now without any response. Central Park Weather: Vegetative Overgrowth Affecting Weather Readings - WABC-TV (New York-WABC, August 22, 2003) - Forecasting the weather is not easy. Government equipment can often be blamed for giving faulty weather information. As Bill Evans explains, a big culprit may be some of the equipment buried in Central Park. Rainfall, snowfall, and the temperature are all vital information recorded 24 hours a day at the weather station located in the heart of Central Park. But meteorologists like Michael Schlacter have serious concerns about the accuracy of the stations data. It sits amid overgrown vegetation and he says thats the problem. The leaves can trigger snow gauges and trees can warp rain and wind measurements. On this hot day, a temperature gauge is in the shade instead of direct sunlight. Michael Schlacter, Weather 2000: "Its kind of like driving a car without a speedometer, odometer, and gas gauge. You are running with false information." The weather instruments at Belvedere Castle have long adorned the top. There used to be a government meteorologist here in the city to keep an eye on them. But now the nearest meteorologist is 60 miles that way. But National Weather Service meteorologists say they knew the weather readings in the park would never be as keenly accurate as the ones at the airports where guidelines prevent foliage from being within 100 feet of the station. Schlacter: "We knew that at times we would have flaky readings, that leaves would fall in gauges, that we would have problems with visibility sensors." [NWS Meteorologist-in-Charge Michael] Wyllie says the weather station is there because it was historically significant to maintain its presence in the park. He says theres been a lot of growth because of the wet spring at so much in fact that temperatures have routinely been recorded lower in the park than at the airports. Wyllie: "We are actually having a micro climate system there because of the vegetation." Imperfect perhaps but nonetheless the system provides the official record of weather for the country's largest city. And Michael Schlacter says its a city that deserves better. Schlacter: "I think New Yorkers deserve a lot better, and I think they deserve the best weather station money can buy." Copyright 2003 ABC Inc., WABC-TV Inc. Data for January 1, 2006 through December 31, 2006 Click column heading to sort ascending, click again to sort descending. State Name Station Type Number of Days Max Temperature >= 90 NJ PLAINFIELD COOP 30 NJ HARRISON COOP 30 NJ TETERBORO AIRPORT WBAN 30 NJ NEWARK LIBERTY INTL AP WBAN 27 NJ CRANFORD COOP 24 NJ MIDLAND PARK COOP 24 NJ CANOE BROOK COOP 22 NY LAGUARDIA AIRPORT WBAN 22 NY BRONX COOP 21 CT DANBURY COOP 20 NY DOBBS FERRY-ARDSLEY COOP 18 NY WEST POINT COOP 18 NJ CALDWELL ESSEX COUNTY AP WBAN 16 NY MINEOLA COOP 16 NY NEW YORK AVE V BROOKLYN COOP 15 NY PORT JERVIS COOP 13 NY WANTAGH CEDAR CREEK COOP 13 CT NORWICH PUBLIC UTILITY PLANT COOP 12 NY JFK INTERNATIONAL AIRPORT WBAN 12 NJ ESSEX FELLS SERVICE BLDG COOP 11 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 11 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 11 NY ISLIP-LI MACARTHUR AP WBAN 10 NY MONTGOMERY ORANGE COUNTY AP WBAN 10 NY RIVERHEAD RESEARCH FARM COOP 9 NY MIDDLETOWN 2 NW COOP 9 NY FARMINGDALE REPUBLIC AP WBAN 9 NY NY CITY CENTRAL PARK WBAN 8 NY WESTHAMPTON GABRESKI AP WBAN 8

I am getting a few breaks of sun here in SW Suffolk.

The sea breeze makes it difficult for coastal sections to lead on 90° days. But JFK has become the high dewpoint leader in recent years. ISP has also seen a dramatic increase in 75° Miami Dewpoint days. Notice how many top years there have been since the super El Niño. Top years with the most 75° dewpoint days JFK 43…2018 26….2019 24….1983 19….2016 18….2021 18….1999 17….2020 17….2017 17….1995 16….1984 15….1988 15…..1987 13….2012 13….1959 13….1955 11….2005 11….1991 ISP 34….2018 26….2020 22….2021 19….2005 18….2019 15…1979 15…1975 14….1998 14….1995 13…2016 13…2002 11…1999 10…2001 10…1990 10…1988 10…1987

Clear skies today just to our NW.

The blocking just changed locations. We had a strong -AO block in April. Now the models are forecasting a record SE Canada block in the coming days.

It could be a short window of opportunity if the models are correct about the next trough in 8-10 days.

The first 90° readings of the season look possible for New England by next weekend. Very unusual skinny 588 dm ridge over the cutoff low. If the winds stay S or SE, then NYC and LGA may only top out in the upper 70s. But a SW flow would be easy 80s even for NYC and LGA.

Yes. The most among the major sites like NYC, EWR, and LGA. Central Park would regularly tie or lead for the most 90° days from the 1930s to 1980. But the tree growth over the equipment has prevented it from happening since 1980. If the station was properly maintained, NYC could have lead the area or tied for the most 90° days several years since then. Years when Central Park lead or tied for most 90° days 1936 NYC….26 EWR….22 1937 NYC…22 EWR…22 1939 NYC…24 EWR…24 1941 NYC…29 EWR…27 1953 NYC….32 EWR….32 1962 NYC….18 EWR….14 1966 NYC…35 EWR….33 1967 NYC…..9 EWR….7 1969 NYC….16 EWR…15 1970 NYC…29 EWR….29 1976 NYC…15 EWR..15 1980 NYC…32 EWR…27

Sneaky freezing layer near 850 mb.

The block over the top of this cutoff low will approach record levels for early May exceeding 588 dm in spots.

Slight increase in days during May staying under 55° at LGA since 1981 compared to the big winter increase in days over 55°.

Sunday looks like low clouds and drizzle near the coast with a sunny day just to our NW.

We can clearly identify the mid 1990s into the early 2000s as the period when the trees began to cover the Central Park equipment. From the 1950s through the early 1990s, NYC would record 90 degree days in reasonable agreement with either EWR or LGA. Then NYC fell far behind during the 2000s when tree growth caused the high temperature readings to become unreliable. Sample years for 90 days since 1955 1955 EWR…32 NYC….25 LGA…..29 1966 EWR….33 NYC….35 LGA….25 1977 EWR….26 NYC….23 LGA…..14 1980 EWR…27 NYC…32 LGA….22 1983 EWR…40 NYC…36 LGA….31 1988 EWR….43 NYC….32 LGA…..26 1991 EWR…41 NYC…39 LGA….34 1999 EWR….33 NYC….27 LGA….26 2005 EWR….37 NYC….23 LGA…..30 2006 EWR…..27 NYC…..8 LGA……22 2010 NYC…54 NYC….37 LGA….48 2016 EWR….40 NYC…..22 LGA…..32 2020 EWR….31 NYC….20 LGA…..34 2021 EWR….41 NYC…..17 LGA…..25

Looks like someone drew the northern rainfall cutoff with a ruler. This is what happens with such an elongated record block over SE Canada.The line extends from south of Detroit due east into the Atlantic. So the cutoff gets stuck for days underneath.

Even JFK along the South Shore still hasn’t made it above 72° yet. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jan 1 to May 6 Missing Count 1 2019-05-06 70 0 - 1975-05-06 70 0 - 1968-05-06 70 0 2 2014-05-06 71 0 - 1961-05-06 71 0 - 1954-05-06 71 1 3 2022-05-06 72 1 - 1971-05-06 72 0

This has been some of the strongest spring onshore flow influence that we have seen around here. Very sharp dividing line between west of Central Park and east. LGA still hasn’t had a 75° day yet. So it’s already the 5th latest. 74° is also the 3rd coldest high at LGA by May 6th on record. First/Last Summary for LAGUARDIA AIRPORT, 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 First Value Last Value Difference 1981 05-21 (1981) 76 09-27 (1981) 79 128 1984 05-19 (1984) 76 10-28 (1984) 80 161 1975 05-14 (1975) 75 11-04 (1975) 75 173 1988 05-13 (1988) 75 10-02 (1988) 79 141 1971 05-11 (1971) 80 11-02 (1971) 76 174 1940 05-07 (1940) 79 10-15 (1940) 77 160 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jan 1 to May 6 Missing Count 1 1940-05-06 71 1 2 1984-05-06 73 0 - 1975-05-06 73 0 - 1971-05-06 73 0 3 2022-05-06 74 1 - 1988-05-06 74 0 - 1981-05-06 74 0

It will be a battle of where the cutoff finally stalls out. The Euro keeps areas near the coast in an onshore flow. If the Euro is correct, then NYC and LGA may not be able to get their first 80° day yet. But we’ll have to wait for later model runs to see if the 80° over the top warmth to our NW can work down closer to NYC. We just need the Bermuda high to be a little stronger than the backdoor high to the north for the first 80° in NYC and LGA.

The NYC Central Park minimum JJA average temperature rise between 1951-1980 and 2010-2021 actually matches the other stations. So this is how we can see that the dense foliage is blocking the sun during the daytime. I included all our major weather stations in the analysis below. It’s interesting that the stations on the Long Island Sound saw the greatest minimum temperature increase. So LGA and BDR are our only stations with a 3° low temperature increase. 1951-1980 to 2010-2021 JJA average temperature increase NYC….max….+0.5….min +2.3 EWR….max…+2.3…..min…+2.3…identical to NYC Central Park LGA…..max….+2.6….min….+3.2 JFK……max....+2.2…min….+2.4 ISP…….max…..+2.7….min….+2.7……records start in 1964 BDR…..max…..+2.1…..min……+3.1…similar to LGA

Next week could be the thinnest record breaking ridge with a cutoff underneath that we have seen this time of year.

Feel free to cut and paste, copy, or take screen shots of the posts in this thread. I put out this data and analysis for everyone to freely share. You can add the post below to an email and send it along to him. The Central Park equipment was out in the sun and away from the deep shade during the 1951-1980 climate era. So we can compare how the high temperatures during the summer have changed between EWR, NYC, and LGA since then. The tree growth over the equipment has trimmed 2° off the NYC summer high temperatures relative to EWR and LGA. This has resulted in many lost recent heat records for NYC as the record warmth dramatically increased since 2010. Central Park should be averaging 10 more annual 90° days instead of just 1 if it was out in a grassy clearing away from the deep shade and cooling foliage. This error in temperature measurement became obvious after the mid 90s ASOS installation in NYC Central Park. 2010-2021 summer high temperature warming over 1951-1980 NYC 1951-1980……83.0……2010-2021….83.5…..+0.5….should be closer to 85.5 or +2.5 away from the shade EWR…83.4…..85.7…+2.3 LGA….82.0…..84.6...+2.6 90° days change NYC….18……19……+1…should be +10 and 28 days a year of 90° EWR….23....33…….+10 LGA…..15…..26…….+11 Link to photos and news stories on overgrowth of vegetation around the sensors http://www.weather2000.com/ASOS/NYC_ASOS.html

This has been our default summer pattern since 2018.

Yeah, another summer on the Euro with the subtropical ridge and Bermuda high pushing up into the Canadian Maritimes.

Yeah, the Euro,GEM, NAM, and RGEM have really slowed the progress of the cutoff low. So several models now have 2.00+ for the area.

The big 90° day leader at JFK las well as our other stations was 2010. But you can see how many top 10s there were in recent years. I bolded the 6 top 10 years since the post 2010 much warmer period began, 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 Max Temperature >= 90 Missing Count 1 2010 32 0 2 1983 26 0 3 2002 21 0 4 1971 18 0 - 1949 18 0 5 2005 17 0 - 1991 17 0 6 2012 16 0 - 1959 16 3 - 1955 16 2 7 2016 15 0 - 1995 15 0 - 1961 15 0 8 1999 14 0 - 1988 14 0 - 1966 14 0 - 1952 14 0 9 2011 13 0 - 1993 13 0 - 1984 13 0 - 1977 13 0 - 1970 13 0 - 1969 13 0 - 1963 13 0 10 2020 12 0 - 2015 12 0 - 2006 12 0 - 2003 12 0 - 1978 12 0 - 1968 12 0 - 1953 12 0