bluewave

Absolutely. Just compare the old photos of the site from the recent ones. Most of those 100° readings from the 1930s into the early 1990s would have only been mid to upper 90s if the they had the same tree cover back then. The strongest wind gust is still 78 mph set back in December of 1974 when the trees were much lower. So there could have been higher gusts in the interim but the tress could be interfering like with the temperatures.

As I have pointed out, you are putting way too much stock in what the teleconnections have been to the north of the subtropics. No combination of WPO, EPO, PNA, AO, or NAO is going to produce a cold and snowy outcome along the I-95 corridor in the Northeast provided that the winter subtropical ridge remains so robust. We need a weaker Southeast Ridge/ Western Atlantic Ridge along with a much slower Pacific Jet. This is why even the -WPO, -EPO, +PNA, and record -AO -NAO block last February still produced a cutter with record snows in Toronto and Montreal with a rainstorm along the coast. The -5 sigma Greenland block linked up with the Southeast Ridge when in the past there would have been a deep trough underneath and a benchmark I-95 blizzard. The issue is the fast Pacific flow and robust subtropical ridges from Japan to Western Europe. So these ridges to the south joining with the ridges associated with the -WPO, -EPO, +PNA, -AO, and -NAO don’t leave any room for cold trough development under the ridges.

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.

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.

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.

None of our current teleconnection indices accurately capture the changes we have seen in the North Pacific since 2018-2019 that I have highlighted in my previous posts. The record ridge near the Aleutians and to the east of Japan and attendant shift north in the storm track doesn’t fit neatly into either the Western Pacific oscillation of the North Pacific oscillation. Same goes for the record SSTs across the mid-latitudes of the North Pacific and Atlantic and subtropical ridge expansion. This is why the snowfall outcome was the same last winter with the strong -WPO interval in February as it had been with prior +WPO intervals. Both outcomes featured very strong Southeast Ridge patterns.

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.

We have been seeing these lulls in recent years when the subtropical warming has increased faster than the tropics. But often by later in the season SST anomalies between the tropics and subtropics balance out. So the tropics sit quietly gaining record amounts of heat through the season with suppressed convection. But when the hurricanes do finally form later on, we get these rapidly intensifying hurricanes becoming majors right before landfall on the Gulf Coast. Different from the old days when most hurricanes seemed to weaken right before landfalling.

Severe storms usually overperform when we have steep lapse rates and such unstable soundings.

The record WPAC warm pool and Aleutian Ridge are much more amplified than we typically see from +WPO patterns. Same goes for the new way the -PDO has played out in the 2020s. So the hemispheric expansion of the subtropical ridges are creating their own pattern.

Early split picture showing up in the data. It was a warmer than average May across the Arctic. But not as warm as 2020 was which lead to all the preconditioning that year. June was the coolest in the Arctic over the last decade. Yet the extent is currently in 1st place for lowest in early July. But the area is only 8th lowest. Area and melt pond fraction are more important this time of year than extent in trying to guess a September low. Unfortunately, the May melt pond data still hasn’t been released. This is what the statistical model uses to forecast a June September low. If I had to take an early guess, the higher area now than extent could mean that the extent will fall behind the steep 2012 drop which happened back in early August 2012. So it’s possible that the 2012 record low will hold for another year. But I want to see the May melt pond fraction first before making a final call. I will update this if the ARCUS SPIN site gets around to posting the model forecasts for September. They have been delayed in their update.

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.

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

This -PDO being driven by the warm SST anomalies from Japan to north of Hawaii since 2019 is something new for us. The pattern has lead to warmer winters and record low snowfall due to the storm track through the Great Lakes and a faster Northern Stream of the Pacific Jet. Very amplified Aleutian Ridges have become the norm. It has also resulted in the Greenland blocking linking up with the Southeast Ridge. So strong subtropical ridges across the Pacific and Atlantic basins. The previous extended -PDO interval from 2007 to 2013 was more defined by the cold pool west of North America and a weaker warm pool east of Japan. Much weaker Aleutian Ridges and no Southeast Ridge in the East. So we didn’t have the Greenland blocking linking up with the Southeast Ridge. During the extended -PDO phase from 1950 to 1976 there was also a much weaker Aleutian Ridge along with much cooler SSTs in both basins. So there wasn’t any linkage between the Greenland blocking and Southeast Ridge.

The 108° high in Mineola was in 2010. There wasn’t any data for July 2011. Then the station shut down right after that. July 4th, 1978 was the only year there with a high in the upper 50s. Time Series Summary for MINEOLA, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2010 108 0 2 2001 105 32 3 1999 103 10 - 1966 103 0 4 1988 102 50 - 1975 102 1 - 1948 102 1 5 2002 101 0 - 1973 101 0 - 1968 101 0 - 1952 101 0 6 2006 100 1 - 1993 100 8 - 1991 100 0 - 1957 100 12 - 1955 100 3 High Temperature Data for July 4, 1978 through July 4, 1978 Click column heading to sort ascending, click again to sort descending. NY MINEOLA COOP 57 CT DANBURY COOP 59 NJ JERSEY CITY COOP 60 NY SCARSDALE COOP 60 NY NY WESTERLEIGH STAT IS COOP 61 NY WESTCHESTER CO AP WBAN 61 NY ISLIP-LI MACARTHUR AP WBAN 61 CT NORWICH PUBLIC UTILITY PLANT COOP 61 NY PORT JERVIS COOP 62 NJ PLAINFIELD COOP 62 NY LAGUARDIA AIRPORT WBAN 62 NY NY CITY CENTRAL PARK WBAN 62 NY VANDERBILT MUSEUM COOP 62 NY SETAUKET STRONG COOP 62 NY DOBBS FERRY-ARDSLEY COOP 62 NY WEST POINT COOP 62 CT GROTON COOP 62 NY BRIDGEHAMPTON COOP 62 NY NEW YORK LAUREL HILL COOP 63 NJ TETERBORO AIRPORT WBAN 63 NJ CRANFORD COOP 64 NJ NEWARK LIBERTY INTL AP WBAN 64 NY NEW YORK AVE V BROOKLYN COOP 64 NY PATCHOGUE 2 N COOP 64

Maybe the ASOS back in 1966 wasn’t so close to the water at LGA. But not sure. The current location is right on the bay near the NW corner of the airport. Data for July 3, 1966 through July 3, 1966 Click column heading to sort ascending, click again to sort descending. NY LAGUARDIA AIRPORT WBAN 107 NJ NEWARK LIBERTY INTL AP WBAN 105 NY NEW YORK AVE V BROOKLYN COOP 105 NY PORT JERVIS COOP 104 NY NEW YORK LAUREL HILL COOP 104 NY JFK INTERNATIONAL AIRPORT WBAN 104 NY ISLIP-LI MACARTHUR AP WBAN 104 NJ ELIZABETH COOP 103 NY NY CITY CENTRAL PARK WBAN 103 NY WEST POINT COOP 103 NY MINEOLA COOP 103 NJ PLAINFIELD COOP 102 NJ JERSEY CITY COOP 102 NY NEW YORK FLOYD BENNETT FIELD WBAN 102 NJ LITTLE FALLS COOP 102 NY SCARSDALE COOP 102 NY BEDFORD HILLS COOP 102 NY NY WESTERLEIGH STAT IS COOP 101 NJ PATERSON COOP 101 NY DOBBS FERRY-ARDSLEY COOP 101 NY STEWART FIELD WBAN 101 NY HEMPSTEAD GARDEN CITY COOP 101 CT NORWALK GAS PLANT COOP 101 CT DANBURY COOP 101

Very difficult to know ahead of time when dealing with the sea breeze at JFK. Both stations in Ozone Park made it to 104°-105° on the other side of the Belt Parkway. So JFK would have done it if the sea breeze could have held off for an hour or two more.

It’s still a toss up whether we make it back to 100° this summer. Since some years with 100° in June did like 2024 and others like 2021 didn’t. Our next chance may be later in July. Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 2025 103 95 M M 103 2021 103 97 99 91 103 2011 102 108 98 88 108 1994 102 99 95 92 102 1993 102 105 100 100 105 1952 102 98 92 94 102 1943 102 95 97 93 102 1988 101 101 99 86 101 1966 101 105 95 91 105 2024 100 99 100 87 100 1959 100 93 96 93 100 1953 100 99 102 105 105 1934 100 98 90 85 100

Over the top warm up for the 4th. Climatologist49‬ ‪@climatologist49.bsky.social‬ · 17h A large part of the western North Slope of Alaska with official forecast high temps over 90F today and tomorrow. This is borderline unprecedented if it happens. There are no weather stations in those 90F+ forecast areas though. So verification will basically be impossible. @alaskawx.bsky.social 11 66

This extreme subtropical SST warming leads to a semi-permanent -PDO +AMO pattern with amplified subtropical ridges.

Best structure on a supercell since moving up here. Very heavy downpour and gust to 44 mph. Detected some broad rotation. Jul 3, 6:05 pm 79 66 65 W 29G44

It can work both ways like we saw last summer. The record subtropical warmth and stable conditions lead to the lull in activity from late August into early September. But then it became very active later in the season.

The summer of 1966 heatwave was very short compared to our summers these days. The major heat only lasted for around 3 weeks. The summer before and after that period wasn’t very warm by today’s standards. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. 1966-06-23 93 61 1966-06-24 97 73 1966-06-25 85 63 1966-06-26 78 62 1966-06-27 101 68 1966-06-28 90 74 1966-06-29 90 71 1966-06-30 94 72 1966-07-01 87 71 1966-07-02 102 70 1966-07-03 105 75 1966-07-04 100 78 1966-07-05 87 74 1966-07-06 87 73 1966-07-07 93 76 1966-07-08 91 70 1966-07-09 89 67 1966-07-10 93 70 1966-07-11 96 72 1966-07-12 98 72 1966-07-13 100 77

The ridge is verifying further south toward the subtropics than the climate models have been forecasting. They theorize that this pattern is related to decreasing snow and sea ice. But I think it could be driven by the subtropics and tropics forcing a 500mb standing wave pattern. Perhaps, there is an interplay at work between all the regions which the climate models haven’t able to pick up on. In any event, the study below came out in 2014 and we have been seeing this pattern quite a bit in recent years. So the forecast from 2014 picked up in something happening in the climate system even though it’s could very well be an incomplete assessment.

The current steep -PDO drop in June was driven by the very impressive subtropical ridge which went across the whole Northern Hemisphere leading to the record subtropical SSTs.