bluewave

I am not sure if any of the current forecasters are even aware of the issue. The errors with the weather data from the park began to really become obvious back in the early 2000s. That’s when most of the media attention was focused on it. The NWS left 30 Rock back in 1993 and the new Central Park ASOS went online around 1995. So the nearly all the forecasters familiar with the more reliable NYC readings before the 1990s change have already retired. I met a few of the forecast crew that were active in the 1970s and 1980s.They really made sure the readings from the park were reliable since they would frequently go over there to take snowfall measurements and monitor the temperature readings. The MIC back into those days commented that they didn’t like to substitute LGA temperatures when the park equipment was vandalized at time since it was cooler than NYC in the summer. When I was growing up before the tree growth Central Park was often near or at the top for high temperatures during the big heatwaves like in July 1977. Monthly Data for July 1977 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. NY NEW YORK LAUREL HILL COOP 104 NY NY CITY CENTRAL PARK WBAN 104 NY DOBBS FERRY-ARDSLEY COOP 103 NJ NEWARK LIBERTY INTL AP WBAN 102 NJ TETERBORO AIRPORT WBAN 102 CT NORWALK GAS PLANT COOP 102 NJ ESSEX FELLS SERVICE BLDG COOP 101 NY WEST POINT COOP 101 NY VANDERBILT MUSEUM COOP 101 NJ PLAINFIELD COOP 100 NJ CRANFORD COOP 100 NY NEW YORK AVE V BROOKLYN COOP 100 NY NY WESTERLEIGH STAT IS COOP 100 NJ LITTLE FALLS COOP 100 NY MARYKNOLL COOP 100 CT STAMFORD 5 N COOP 100 NY SCARSDALE COOP 100 CT NEW HAVEN COOP 100 CT MIDDLETOWN 4 W COOP 100 NJ CANOE BROOK COOP 99 NY LAGUARDIA AIRPORT WBAN 99

The strongest heat missed to our north yesterday with Manchester, NH reaching a record high of 97°. Manchester made it to 97° 3 times since 1999 from June 1st to June 18th. The other times Newark reached to 97° to 99° instead of just 92° yesterday. So this ridge orientation allowing onshore flow to make it to Newark with such record heat in New Hampshire is unusual. It’s becoming more common since we started seeing such strong high pressure to the east of New England with these summer heatwaves back around 2018. 6-18-24 Manchester…97°…..Newark….92° 6-12-17 Manchester…97°…..Newark…97° 6-10-08 Manchester….100°….Newark….99° 6-7-99 Manchester….97°……Newark….99°

Yes. Many stations on Long Island had more 90° days back in 2006. Data for January 1, 2006 through December 31, 2006 Click column heading to sort ascending, click again to sort descending. NJ PLAINFIELD COOP 30 NJ HARRISON COOP 30 NJ TETERBORO AIRPORT COOP 30 NJ TETERBORO AIRPORT WBAN 29 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 NY JFK INTERNATIONAL AIRPORT WBAN 12 CT NORWICH PUBLIC UTILITY PLANT COOP 12 NJ ESSEX FELLS SERVICE BLDG COOP 11 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 11 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 11 NY MONTGOMERY ORANGE COUNTY AP WBAN 10 NY ISLIP-LI MACARTHUR AP WBAN 10 NY MIDDLETOWN 2 NW COOP 9 NY FARMINGDALE REPUBLIC AP WBAN 9 NY RIVERHEAD RESEARCH FARM COOP 9 NY NY CITY CENTRAL PARK WBAN 8 NY WALDEN 1 ESE COOP 8 NY OCEANSIDE COOP 8 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 8 NY YORKTOWN HEIGHTS 1W COOP 8 NY WESTCHESTER CO AP WBAN 8 NY WESTHAMPTON GABRESKI AP WBAN 8 NY SETAUKET STRONG COOP 8 NJ CHARLOTTEBURG RESERVOIR COOP 7 NJ ELIZABETH COOP 6 NY CENTERPORT COOP 6 NY BRIDGEHAMPTON COOP 6 NY MONTAUK AIRPORT WBAN 6

There were several news reports in the local media back around 2003 when non NWS forecasters were noticing how much Central Park started to deviate from past performance. They interviewed the MIC at the NWS at Upton and he basically told them he knew that the readings at the park wouldn’t be as reliable but settled for it since the other option offered to them was to close down the Central Park station. So they chose to live with inaccurate temperatures and other measurements rather than retire the station after the NWS moved out to Upton in 1993. So the media lost interest in the temperature issue since then which has only grown worse with further tree and vegetation growth close into the sensor. But to Lonnie’s credit he went there and measured the snowfall himself during the storm last winter and got the higher total since the conservancy measured too late and the snow settled. Maybe one of these days an enterprising journalist will explore the temperature issues when the trees are fully leafed out. The NWS probably doesn’t want to touch this issue after all this time since it could call into question the reliability of the weather readings from the biggest city in the nation.

Record heat to our NW today.

The 1936 record high in Central Park looks good to me. The WB office down near the Battery is subject to cooling breezes off NY Harbor. Open areas of the park where they used to measure temperature were traditionally one of the warmest spots around the area before the ASOS was located under the trees in 1995. Notice how many 104° to 106°readings there were back in July 1936. If we ever had a repeat of the dust bowl in this much warmer climate places other than the current NYC ASOS would easily go 110°+. Data for July 1, 1936 through July 31, 1936 Click column heading to sort ascending, click again to sort descending. NJ PLAINFIELD COOP 106 NY NY CITY CENTRAL PARK WBAN 106 NY PORT JERVIS COOP 105 NJ ELIZABETH COOP 105 NJ JERSEY CITY COOP 105 NJ LITTLE FALLS COOP 105 NJ PATERSON COOP 105 NJ CHARLOTTEBURG RESERVOIR COOP 105 NY SCARSDALE COOP 105 NY BEDFORD HILLS COOP 105 NJ NEWARK LIBERTY INTL AP WBAN 104 NY FLUSHING COOP 104 NY WEST POINT COOP 104 NY MOUNT VERNON COOP 103 NY HICKSVILLE COOP 103 NY CARMEL COOP 103 CT WATERBURY ANACONDA COOP 103 CT WATERBURY CITY HALL COOP 103 NJ CANOE BROOK COOP 102 NY WORLD TRADE CENTER WBAN 102

It’s not about cutting down trees or paving over everything. NYC is the only major station in a park or rural setting that placed the ASOS under trees in 1995. The New Brunswick station is a great example of how to place a weather station in a more suburban or rural setting. Notice how the trees are away from the thermometer and the equipment isn’t in the shade. NYC fundamentally changed how they measure temperature back in the 90s so it created a discontinuity in the long term climate record. I guarantee you if they placed the equipment on the great lawn instead the highs wouldn’t be that much different from Newark. Going by what NYC and Newark recorded with 90°days before the 90s, NYC would probably have 29 days reaching 90° each year vs 33 at Newark instead of the 17 of recent years. So the tree growth over the last 30 years has resulted in a reduction of around 12 days reaching 90° a year. You will also notice that the New Brunswick station even though there are trees and grass around has seen a steady increase in 90° days over the years.

Some spots could approach the 3”PWAT local record.

Highest temperatures this hour up in New Hampshire with the heat index pushing 100° in Mass. JAFFREY NH SUNNY 91 66 43 S7 NORWOOD SUNNY 89 74 60 SW7 30.21R HX 98

This is what it used to look like before the trees began to grow over the sensor and put it in on the shade since the 90s. There is no way NYC would have made it to 106° back in 1936 if they had the same tree coverage that do now.

Even the higher dew points are going over the top. WATERTOWN MOSUNNY 79 72 Kennedy Intl MOSUNNY 75 67

When they set up the new ASOS back in 1995 it moved under the trees and into the deep shade. It used to get direct sunlight before the move. That’s why NYC used to more in line with Newark before the move. There were some heatwaves like July 1977 when NYC was hotter than Newark. Back in the 1970s before the tree growth in Central Park NYC averaged only 3 fewer 90° days a season than Newark. Now the number has grown to 13° fewer. There is no reason that NYC should have the same amount of 90° days it had back the 70s as it has today. Annual number of 90° days 1970-1979…..Newark….20…..NYC…..17 2014-2023….Newark…..33….NYC….17

Good to see others pointing out the unrealistically high Euro temperatures which were over 105° in spots and have been backing off each run.

Yeah, the tree growth has gotten so dense over the last decade that NYC has set the record for longest streak not going over 98° since 7-19-12. Number of Consecutive Days Max Temperature < 99 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 1 4351 2012-07-19 through 2024-06-16 2 4022 1966-07-14 through 1977-07-17 3 3260 1885-07-22 through 1894-06-24 4 2844 1903-09-19 through 1911-07-02 5 2212 1911-07-11 through 1917-07-30

When have had our actual 100° days at Newark in recent years both the GFS and Euro agreed with each other and the HRRR came on board once within its 48 hour range. The Euro and GFS would have highs forecast in the upper 90s and then the warmth usually overperformed by a few degrees.

I remember something like this several years ago after they did an upgrade to the GFS. The model developed a warm bias right after one of the upgrades and they eventually fixed it. Now it’s looks like they did an upgrade to the OP Euro that has given it a warm bias beyond 3 -4 days out and especially after 120 hrs. So I have been mostly relying on the GFS, GEFS, and EPS means for the high temperatures beyond 72-96 and especially 120 hrs. We didn’t have much heat last summer so not sure exactly when this error began. The Euro did pretty well with the record heat during the summer of 2022. New run Old run

The GFS has been doing much better than the Euro recently. The Euro had the core of the heat focused over our area last week. Now the new Euro takes the core of the heat to our north into upstate New York and New England. Plus the 850 mb to surface temperatures have been running too high. This matches our pattern of recent years with a further north subtropical ridge into New England allowing more SSE flow at times. We will probably see our warmest temperatures later in the week and possibly into the weekend as the flow turns more SW. New run 0z JUN 20 Old run ridge axis and core of heat too far south

Yeah, the HRRR has the strongest Ambrose Jet of the season today with 30-40 mph gusts at the South Shore beaches.

I think portions of New England have a shot at their all-time June warmest temperatures as this starts out in true over the top fashion with the subtropical ridge pushed much further north than usual. All-time max 500mb height records could also be challenged.

NYC hasn’t been able to get over 98° since late July 2013 since the vegetation got so thick. This is the longest streak on record. During the strongest heatwaves in recent years we had to subtract 2° to 5° off of wherever the max was at Newark. Number of Consecutive Days Max Temperature < 99 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 1 4350 2024-06-15 2 4022 1977-07-17 3 3260 1894-06-24 4 2844 1911-07-02 5 2212 1917-07-30

Sunday morning may be the coolest we see for a while with 40s and some pockets of 30s over the interior Northeast.

Yeah, that’s why JFM 15 was so special for you guys. Historic -EPO and +PNA block. The El Niño was weak enough so the northern stream was able to dominate. It’s interesting how JFM 15 was one of the most favorable Pacific patterns on record. Just several months later in December 15 we began to shift toward some of the most hostile Pacific patterns on record into recent years.

https://wcd.copernicus.org/articles/5/753/2024/ An alternative possibility is that the changes seen in the reanalyses are a combination of natural variability and a forced response that is not represented in CMIP6 models. This might explain why the models are systematically biased towards underestimating the variability in the explained variance of the NAO, as seen in Fig. 3. If part of these changes in the relative strength of the NAO are indeed due to a forced response that is lacking in climate models, then there is a risk of a systematic underestimation of the changing risks of climate extremes over Europe in a warming world. A second alternative is that the change is the results of a long-term, multi-decadal variability (perhaps with a variability of 60–80 years such as that found in studies on Bjerknes compensation). If the models reproduced such oscillations and were initialized in different phases of the multi-decadal signal, this could possibly produce the observed differences in the long-term changes in variance explained by the NAO. However, it would be very difficult to reliably confirm a 60–80-year oscillation in a 150-year simulation since you would barely have two full cycles. Both of these alternatives are speculation and would need significant further investigation to confirm. While the large-scale patterns derived using an EOF analysis are a good indicator of the changes in weather systems over the North Atlantic, recent works have found that jet regimes are better at capturing spatial structure compared to patterns like the NAO and have the advantage of a greater physical connection to the underlying weather systems (Madonna et al., 2021). Future work is planned to investigate how these jet regimes have varied over time in the reanalyses and how well the CMIP6 models capture these variations.

Yeah, this could be one of the strongest June heatwaves on record for areas to our north away from the onshore flow near the coast.

The GFS shows the SSE flow as the heatwave moves in next Tuesday and Wednesday. It has 100s NW of Boston. There could even be near 100° readings just west of the sea breeze influence in portions of Central NJ near Philly. But you can see the core of the +20C 850mb temperature axis starting out just to our north.