bluewave

But the thermometer stays in the shade which keeps it 3-4° colder than out in the open in the Park. http://www.weather2000.com/ASOS/NYC_ASOS.html Central Park Weather: Vegetative Overgrowth Affecting Weather Readings - WABC-TV

The equipment was out in the open before the tree growth began to block the sensors in the 1990s. The NYC thermometer in July 1977 was warmer than Newark and LGA. Most heatwaves before the 90s featured NYC highs more in line the other urban sites. A mesonet on the Great Lawn in Central Park would probably be 3-4° warmer on sunny days in the summer than the current ASOS under the dense vegetation near the castle. Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature 1977-07-13 93 1977-07-14 92 1977-07-15 96 1977-07-16 98 1977-07-17 97 1977-07-18 100 1977-07-19 102 1977-07-20 92 1977-07-21 104 Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature 1977-07-13 92 1977-07-14 91 1977-07-15 93 1977-07-16 97 1977-07-17 99 1977-07-18 98 1977-07-19 100 1977-07-20 90 1977-07-21 102 Data for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature 1977-07-13 92 1977-07-14 89 1977-07-15 90 1977-07-16 96 1977-07-17 95 1977-07-18 95 1977-07-19 99 1977-07-20 90 1977-07-21 99

This may be the first time that NJ had 100° readings with a rotating severe supercell moving across Long Island during the same hour.

That’s quite an impressive hook echo for Nassau County.

Newark back to 97° after the brief rain. https://www.weather.gov/wrh/timeseries?site=kewr Jul 21, 2:20 pm 97 70 42 104 WSW 22 10.00 FEW025 BKN055 BKN110 29.58 29.60 Jul 21, 2:15 pm 95 70 44 101 SW 17 10.00 FEW025 BKN055 BKN110 29.59 29.61 Jul 21, 2:10 pm 95 72 47 103 WSW 17 10.00 FEW020 BKN050 BKN110 29.59 29.61 Jul 21, 2:05 pm 91 74 56 101 WSW 13 10.00 Lt rain FEW020 BKN050 BKN110 29.59 29.61 Jul 21, 2:00 pm 90 73 59 98 SW 12 10.00 Lt rain FEW025 BKN050 BKN110 29.59 29.61

Somerset County trying for a 2nd 100° in a row. Somerville NJ 2022-07-21 13:45 ASOS 97 68 39 29.63 6 SW ▼ Somerville NJ 2022-07-21 13:40 ASOS 97 70 42 29.63 3 W ▼ Somerville NJ 2022-07-21 13:35 ASOS 93 70 47 29.63 5 W

That’s one of the more impressive looking splitting supercells that we have had in a while.

Starting to show some rotation so we’ll have to see if it can tighten up a bit.

This is already day 10 of the heatwave in Somerset County with a high of 95° so far today. https://www.njweather.org/data/daily/3572 ▼ Hillsborough-Duke NJ 2022-07-21 Mesonet 95 69 76 68 98 50 29.72 29.65 0.00 18 W ▼ Hillsborough-Duke NJ 2022-07-20 Mesonet 100 67 72 65 94 35 29.81 29.68 0.00 24 WSW ▼ Hillsborough-Duke NJ 2022-07-19 Mesonet 94 70 71 64 91 40 29.83 29.74 0.00 23 WNW ▼ Hillsborough-Duke NJ 2022-07-18 Mesonet 97 72 76 70 97 44 30.00 29.73 0.00 31 SW ▼ Hillsborough-Duke NJ 2022-07-17 Mesonet 90 68 72 65 100 45 30.05 29.97 0.20 14 W ▼ Hillsborough-Duke NJ 2022-07-16 Mesonet 92 66 70 58 98 35 30.14 30.00 0.00 15 ESE ▼ Hillsborough-Duke NJ 2022-07-15 Mesonet 91 60 68 53 95 31 30.15 30.06 0.00 15 SSE ▼ Hillsborough-Duke NJ 2022-07-14 Mesonet 91 63 69 58 97 36 30.07 29.89 0.00 19 NW ▼ Hillsborough-Duke NJ 2022-07-13 Mesonet 93 67 70 58 95 36 29.91 29.76 0.00 16 W ▼ Hillsborough-Duke NJ 2022-07-12 Mesonet 94 60 72 56 98 46 29.87 29.67 0.00 23 SW

White Plains in Westchester County just tied the highest July dewpoint for 11 am at 77°. White Plains MOSUNNY 88 77 HX 100 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=153&network=NY_ASOS&zstation=HPN&month=jul&var=max_dwpf&_r=t&dpi=100&_fmt=png

Wednesday was the warmest day in Somerset County and parts of Westchester County since 2012. Time Series Summary for SOMERSET AIRPORT, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Year Highest Max Temperature Missing Count 2022 100 164 2021 98 1 2020 96 0 2019 98 1 2018 95 3 2017 95 1 2016 97 0 2015 97 50 2014 94 0 2013 97 4 2012 101 17 Time Series Summary for WESTCHESTER CO AP, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Year Highest Max Temperature Missing Count 2022 97 166 2021 95 5 2020 93 1 2019 95 7 2018 94 0 2017 93 6 2016 95 0 2015 95 3 2014 90 5 2013 94 1 2012 98 2

Newark and Somerset airport both made it to 100° yesterday with westerly flow at Newark before the sea breeze arrived. Data for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature 2022-07-20 100 2022-07-19 94 2022-07-18 93 Data for SOMERSET AIRPORT, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature 2022-07-20 100 2022-07-19 93 2022-07-18 93

When the SSTs and the dewpoints both reach 75° It only takes a weak trigger to set off convection.

The Newark ASOS has been right in line with other urban stations for the last few weeks. There was a period back in June and early July when it was only 1-2° warmer than the other urban sites. But that could just be within the normal warm season variability from station to station. Just check all the other local highs. There hasn’t been any period recently when the Newark ASOS was 4-5° warmer then the next highest temperature in our area.

Yeah, most models like the RGEM have active sea breeze front convection today. The dewpoints are already in the mid 70s on Long Island. Hopefully, the axis of heaviest storms can get your area. MacArthur/ISP PTSUNNY 77 76

We had at least 4 ground level stations reach 100° yesterday across the area. 3 of these stations were mesonets and 1 was Newark airport. So with this new expanded coverage, we are finding out that Newark really isn’t that unique in terms of heat. The local TV and radio outlets need to highlight more than just the NYC ASOS in Central Park which is in error. The dense tree growth shading the sensor can be 3° or more degrees cooler than just a few hundred feet away on an open lawn in Central Park. That is how much cooler a shielded sensor can be tucked under dense vegetation with shade and leaf transpiration. Many TV and radio forecasts were leading with highs of 90-95° yesterday for NYC. This was due to them just focusing on Central Park instead of the whole area. Outside of the immediate shore, the better range was a high of 95° to 100° which models like the Euro and HRRR did very well with. So the artificially cool NYC readings are one reason it’s rare to see 100° in a local broadcast forecast. ▼ Hillsborough-Duke NJ 2022-07-20 Mesonet 100 Newark …….100 Brownsville 100 Corona 100

The Euro has an impressive temperature and dewpoint gradient when the heatwave peaks on Sunday. Highs of 104° in New Jersey with mid 70s dewpoints near the coast. So a very strong Ambrose Jet event with gusts to 35 mph along the South Shore.

You know the soil and vegetation has to be very dry for a farm in Somerset County to be almost as hot as Newark. ▼ Hillsborough-Duke NJ 2022-07-20 15:00 Mesonet 99 https://www.njweather.org/station/3572 https://www.njweather.org/maps/station-locations

High of 99° so far at Newark which is close to the daily record of 101°. https://www.weather.gov/wrh/timeseries?site=kewr 7/20 101 in 1980 100 in 1991 98 in 2019+

95° at South Ozone Park in Queens with the lawn really drying out. https://www2.nysmesonet.org/networks/nyc Current Conditions at Lefferts / South Ozone Park 11:30 AMNortheast Air Temperature 95°F July 20, 2022 11:25 AM EDT Elevation: 32 feet Relative Humidity: 44% Station Pressure: 29.74″ Snow Depth*: -- Liquid-Equivalent Precipitation 6 hours: 0.00″ 1 day: 0.00″

Updated for the 4.31 at Tarrytown and 4.25 at Fair Lawn which were the highest area rainfall totals. https://nwschat.weather.gov/p.php?pid=202207191556-KOKX-NOUS41-PNSOKX

This July is continuing the pattern since 2013 of much lower Arctic summer 500 mb heights than the record 2007-2012 dipole era. The unusually cold conditions with low pressure near the North Pole earlier this month shifted over closer to Alaska this week. The trough has set a new record low 500mb height for July in this area. This has resulted in a slowing of the extent decline rates near the Beaufort and Chukchi seas. https://nsidc.org/arcticseaicenews/ In terms of air temperature, the first half of July 2022 was a tale of regional contrasts (Figure 2a). On the Eurasian side of the Arctic, particularly in the Laptev and Barents Seas, extending toward the North Pole, air temperatures at the 925 mb level (about 2,500 feet about the surface) were 3 to 6 degrees Celsius (5 to 11 degrees Fahrenheit) below average. On the North American side of the Arctic, air temperatures were as much as 8 degrees Celsius (14 degrees Fahrenheit) above average, notably in the southeast Beaufort Sea and the western Canadian Arctic Archipelago. The sea level pressure pattern was dominated by low pressure over the Laptev Sea sector, centered near the North Pole (Figure 2b). Why has no new record-minimum Arctic sea-ice extent occurred since September 2012? https://iopscience.iop.org/article/10.1088/1748-9326/abc047 One of the clearest indicators of human-caused climate change is the rapid decline in Arctic sea ice. The summer minimum coverage is now approximately half of its extent only 40 yr ago. Four records in the minimum extent were broken since 2000, the most recent occurring in September 2012. No new records have been set since then, however, owing to an abrupt atmospheric shift during each August/early-September that brought low sea-level pressure, cloudiness, and unfavorable wind conditions for ice reduction. While random variability could be the cause, we identify a recently increased prevalence of a characteristic large-scale atmospheric pattern over the northern hemisphere. This pattern is associated not only with anomalously low pressure over the Arctic during summer, but also with frequent heatwaves over East Asia, Scandinavia, and northern North America, as well as the tendency for a split jet stream over the continents. This jet-stream configuration has been identified as favoring extreme summer weather events in northern mid-latitudes. We propose a mechanism linking these features with diminishing spring snow cover on northern-hemisphere continents that acts as a negative feedback on the loss of Arctic sea ice during summer.

The HRRR and Euro both have 100° potential today around Newark which has been so dry this month.

The cold January this year was the one outlier from our new climo since 2010. December was the warmest departure month of winter as usual. The record heat at the end of May matched the typical highest departure month of spring. The slow start to summer in June for most was right on also. Now the expected big July warm up right on cue. The August departure should be higher than June was. Then our classic endless summer pattern in September. The monthly temperature increases from 81-10 to 91-20 ……….EWR…..ISP Dec…+1.5….+1.5 Jan….+1.2…+1.3 Feb….+0.5….+0.5 Mar….+0.4….+0.6 Apr….+0.5…..+0.6 May...+0.6….+0.9 Jun….+0.3….+0.6 Jul…..+1.4…..+1.1 Aug...+0.6….+0.9 Sep….+1.0….+1.3 Oct…..+0.9..+1.4 Nov….+0.2..+0.5

Pretty good agreement between the Euro and GFS on the major heat lasting through at least Sunday. The wildcard for Monday will be the timing of the cold front and severe storms. If the front slows down, then we can tack another day onto the major heatwave. 850 mb temperatures rise to around +20C from Wednesday into Saturday. So the warm spots could easily make a run on 100°. The Euro and GFS have 850 mb temperatures peaking at +22C to +24C by Sunday. This means that places that haven’t reached 100° since 2010-2013 could do it on Sunday. Euro 21z Wednesday 21z Sunday