donsutherland1

Bridgeport has now reached 80° this morning. That is the 29th 80° or above day this month. That ties the July record of 29 days, which was set in 1966 and tied in 1994.

August DCA _ NYC _ BOS ___ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 0.3 0.5 0.6 0.4 0.2 0.2 1.6 2.1 2.2

Yesterday's low temperature of 80° at JFK Airport broke the daily mark of 79°. The old record was set in 1995 and tied in 2006. It was the second such low this year, which tied the all-time record of two days set in 1999 and tied in 2016.

It’s available here: https://mesonet.agron.iastate.edu/wx/afos/list.phtml

Central Park (31 days) has tied its July record for most 80F (26.7C) or above days. In addition, July 2025 is the second consecutive July with 31 such days, which sets a new record for most consecutive years. The only other years were 1944, 2022 and 2024.

JFK Airport (31 days) and Newark (31 days) have tied their July records for most 80F (26.7C) or above days. JFK Airport (2 consecutive years) and Newark (4 consecutive years) have their longest streaks of 31 80F (26.7C) or above July days. Neither site had ever had 2 consecutive such years before their current streaks.

Low pressure moving along a nearly stationary front produced heavy thunderstorms with flash flooding in parts of the region. A snippet from the NWS: 000 TTAA00 KNYC 311600 FFWNYC NYC047-059-081-103-NYZ501-311800- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING AND SPECIAL MARINE WARNING NATIONAL WEATHER SERVICE NEW YORK NY 1200 PM EDT WED JUL 31 1996 THE NATIONAL WEATHER SERVICE IN NEW YORK HAS ISSUED A FLASH FLOOD WARNING AND SPECIAL MARINE WARNING EFFECTIVE UNTIL 200 PM EDT FOR THE PEOPLE IN THE FOLLOWING LOCATIONS... IN SOUTHEAST NEW YORK ...KINGS COUNTY...NASSAU COUNTY...QUEENS COUNTY ...WESTERN SUFFOLK COUNTY ...AND THE ADJACENT COASTAL WATERS A FLASH FLOOD WARNING IS NOW IN EFFECT FOR WESTERN SUFFOLK... NASSAU...QUEENS...AND KINGS COUNTIES UNTIL 2 PM. A SPECIAL MARINE WARNING IS ALSO IN EFFECT FOR THE COASTAL WATERS FROM SANDY HOOK TO MORICHES INLET UNTIL 2 PM. A STRONG LINE OF THUNDERSTORMS CONTINUES TO EFFECT THE WARNING AREA PRODUCING TORRENTIAL RAINS...AND DANGEROUS LIGHTNING. THESE THUNDERSTORMS HAVE CAUSED WIDESPREAD STREET...ROADWAY...AND BASEMENT FLOODING. AT 1200 PM THE HEAVIEST RAINS ARE OCCURRING OVER NASSAU COUNTY AND THE COASTAL WATERS SOUTH OF JONES BEACH. THE STORMS WILL EFFECT WESTERN SUFFOLK COUNTY AND ADJACENT WATERS SHORTLY. CONDITIONS WILL SLOWLY IMPROVE OVER QUEENS AND KINGS COUNTY BY 1 PM AS THE LINE OF THUNDERSTORMS MOVES EAST. THESE STORMS HAVE BEEN PRODUCING HEAVY FLOODING RAINS AND FREQUENT DANGEROUS LIGHTNING AND COULD PRODUCE GUSTY WINDS AND SMALL HAIL.

I suspect the changes in Atlantic and Pacific SSTAs have played a role in influencing synoptic patterns and their durability. Out in the Southwest, heat now locks in for longer durations. Heatwaves are more variable in the East (probably a combination of the patterns + wetter climate). Central Park notwithstanding, the region is having a hot summer so far.

For reference for July 31:

FWIW, I ran the numbers and also came up with a slightly decreasing trendline. Avondale is warming slightly faster than Philadelphia.

Tomorrow could be unhealthy. Then, we'll see whether the heavy rain later tomorrow and Friday can wash the particulates out of the air.

I agree. Paris provides a good example of the benefits of greening.

it reached 100° at 4:40 pm.

Newark reached 100° a short time ago.

Temperatures again soared well into the 90s across the region. High temperatures included: Bridgeport: 95° (tied record set in 1949) Islip: 96° (old record: 95°, 1988) New York City-Central Park: 95° New York City-JFK Airport: 95° New York City-LaGuardia Airport: 99° (tied record set in 1988) Newark: 100° A break in the heat is now imminent. A front will cross the region this evening triggering some scattered showers and thundershowers. A few areas could experience strong or severe thunderstorms. Behind the front, it will turn cooler for an extended period of time. A widespread 1.00"-2.00" rainfall with locally higher amounts of 3.00" or more is likely from tomorrow night into Saturday. Generally somewhat cooler than normal conditions will likely persist through the first week of August. There are hints on the long-range guidance that a new round of heat could develop past August 10th. The ENSO Region 1+2 anomaly was +0.6°C and the Region 3.4 anomaly was -0.2°C for the week centered around July 23. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.48°C and the ENSO Region 3.4 anomaly has averaged 0.00°C. Neutral ENSO conditions will likely continue through the summer. The SOI was +5.97 today. The preliminary Arctic Oscillation (AO) was -0.052 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal July (1991-2020 normal). July will likely finish with a mean temperature near 79.5° (2.0° above normal).

Glacial boulders at Franconia Notch State Park. The last boulder was split by the melting and refreezing of the ice. The boulders were deposited around 25,000 years ago as the ice sheet advanced south.

Trees have a cooling effect. In a way, Central Park is providing a demonstration of how trees can blunt at least some of the warming that is ongoing. Here's how things have fared in terms of average summer high temperatures 1961-1990 and 1991-2020 in the New York City area. Central Park is the lone sight showing a slight cooling of mean summer high temperatures.

Islip reached 95 for the fifth time this year. That ties 2025 with 1966 and 2010 for the second most such days. The record of seven days was set in 1999.

I suspect that its urban heat island grew since the 1960s-1970s.

There's a pretty prominent heat signal showing up for parts of the East during the week of August 11-18:

If the numbers are taken as is, there would be 90s. The signal gets damped down over time due to the spread among the ensemble members. It's still fairly prominent at this timeframe.

Here's how 90° or above days have changed in frequency between 1961-1990 and 1991-2020.

90° Days through July 29: Newark: 28 days New York City-LaGuardia Airport: 19 days Bridgeport and New York City-JFK Airport: 13 days Islip and White Plains: 11 days New York City-Central Park: 10 days The following sites have among the five highest number of such days through July 29th: Bridgeport: Tied second Islip: Tied fifth New York City-JFK Airport: Tied third Newark: Tied fifth

Although August will start cool, there is a distinct heat signature showing up on the EFI chart for August 11-18. The period is also forecast to be warmer than normal on the ECMWF weekly guidance.