bluewave

Still south of Corona as they just made it to 100°.

You can see the sea breeze front on radar between LGA and JFK.

Yeah, they usually slowed down in August except for years like 2005.

There were many above average highs which boosted the average. But the 90° day count was much lower last year. Many 85°+ days helped to boost the average high. But 2010 stands alone for 90° days from June 1st through July 28th. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY June 1st-July 28th days reaching 90° and warmer Click column heading to sort ascending, click again to sort descending. 1 2010-07-28 21 0 2 1983-07-28 15 0 3 2012-07-28 13 0 - 1999-07-28 13 0 4 2025-07-28 12 0 - 1952-07-28 12 0 - 1949-07-28 12 0 5 2002-07-28 11 0 - 1963-07-28 11 0 6 2020-07-28 10 0 - 2011-07-28 10 0 - 1991-07-28 10 0 - 1966-07-28 10 0 - 1955-07-28 10 0

Even when using the avarage max it was still in the top 10 for warmth. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY AVG Max Temps June 1st - July 28th Click column heading to sort ascending, click again to sort descending. 1 2010-07-28 86.4 0 2 2011-07-28 84.2 0 3 2025-07-28 83.2 0 - 2020-07-28 83.2 0 4 2008-07-28 83.1 0 - 1966-07-28 83.1 0 5 1999-07-28 83.0 0 6 2024-07-28 82.9 0 - 2016-07-28 82.9 0 7 1991-07-28 82.8 0 8 1983-07-28 82.7 0 - 1963-07-28 82.7 0 - 1949-07-28 82.7 0 9 2012-07-28 82.6 0 - 1971-07-28 82.6 0

The storm track shift around the NYC Metro area occurred during the 2018-2019 winter. From 2009-2010 to 2017-2018 we had a primary 40/70 benchmark storm track. Then in 2018-2019 it shifted to a Great Lakes cutter and I-95 to I-84 hugger storm track with the occasional suppressed Southern Stream track.

Already low 90s and the NYC micronet stations just before 10am.

I get that sometimes here along the LI Sound when there is an inversion with the wetlands nearby.

The ECMWF seasonal forecast system from before the winter missed the +PNA mismatch that I was discussing the potential for last October with the early MJO indicator. So the long range forecasts from months like October were obviously too warm since it missed the correct 500mb pattern. But in previous years without a mismatch, the seasonal model was too cold from October for the 22-23 and 23-24 winter forecasts. It missed the record warmth both winters from the fall seasonal forecasts. Now the 2nd way the Euro was incorrect last winter involved the medium term 15 day EPS. It was too cold overall in the Northeast but did better in other parts of the country. The 500 mb long range pattern forecast for February missed the Southeast Ridge linking up with the -5 AO in mid-February. It had a classic KU look around the time of the big -AO drop. We wound up with the storm cutting west of the big cities leading to the record snows in Toronto and Montreal. In the past we didn’t get these Southeast Ridge linking ups with such strong blocking near -5 SD around Greenland. The model actually did a very good job at the higher latitudes. But missed the subtropical ridge amplification. This is why the heavy snows it had around NYC in the longer range forecasts wound up significantly further north. This has been the case since the 18-19 winter with the big snowstorm always being 8-15 days away. The GFS and CMC have had the same issue so not so not just singling the Euro out. But it’s the highest scoring model overall so it gets more attention. The charts below represent a repeating model error or bias since the 18-19 winter. EPS long range forecast had the classic KU look but missed the strong Southeast Ridge amplification leading to the first February cutter for a -5 -AO

Yeah, 2nd warmest summer on record so far for Long Island with numerous top 10s since 2010. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY Warmest June 1st- July 27th Click column heading to sort ascending, click again to sort descending. 1 2010-07-27 77.8 0 2 2025-07-27 75.9 0 3 2011-07-27 75.8 0 4 2024-07-27 75.6 0 5 2008-07-27 75.2 0 - 1948-07-27 75.2 46 6 2020-07-27 75.1 0 7 2016-07-27 75.0 0 - 2013-07-27 75.0 0 - 1994-07-27 75.0 0 8 1983-07-27 74.9 0 9 2012-07-27 74.7 0 - 1949-07-27 74.7 0 10 1999-07-27 74.6 0 - 1991-07-27 74.6 0 - 1952-07-27 74.6 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Warmest June 1st-July 27th Click column heading to sort ascending, click again to sort descending. 1 2010-07-27 75.0 0 - 1999-07-27 75.0 0 2 2025-07-27 74.9 0 3 2024-07-27 74.3 0 4 2013-07-27 74.1 0 - 1994-07-27 74.1 0 5 2020-07-27 73.8 0 6 2011-07-27 73.7 0 7 2008-07-27 73.6 0 8 2019-07-27 73.5 0 9 1966-07-27 73.0 0 10 2014-07-27 72.9 0 - 1991-07-27 72.9 0

The record breaking smoke back in June 2023 dropped the temperature by 5.4°F. https://www.nature.com/articles/s43247-025-02214-3

Well the ridge axis has been further west than recent years. Recent summers it has been east of New England with more onshore flow. So this is why places like JFK have seen more 100° days with the increased westerly flow.

None of the models had 100° today anyway. The heat was always expected to peak Tuesday into Wednesday. Smoke only becomes an issue for temperatures when it’s thick enough. Even then the effect would only be a degree or two unless we have June 2023 levels which was historic due to the magnitude and closeness of the wildfires in Canada. The current wildfires are further away in Canada so it hasn’t been as thick as 2023. But a few days ago the low level smoke was thick enough to drop the air quality.

Last winter the underestimation of the Southeast Ridge or Western Atlantic ridge occurred with the storm track. So the heaviest snows kept shifting north right up until storm time with a stronger ridge than forecast. But in previous winters it has been both storm track and the overall average 500 mb pattern that the models regularly underestimate.

These smoke forecasts from the models vary quite a bit from run to run. So it’s much more of a trial and error process. Always have to check in the mornings to see how close to reality the HRRR and other models are doing.

Another longer range modeling underestimation of the Southeast Ridge which has been a frequent occurrence last decade.

Very strong La Niña background state continuing with the record July heat and Southeast Ridge. So a continuation of these record subtropical ridges. The models have frequently been underestimating the heat and ridging in the East.

I think that the 09-10 and 10-11 winters were so phenomenal, that we just couldn’t sustain that level of historic snowfall production for 3 seasons in a row.

I can see some -AO and -NAO overlap also. Like last 24-25 winter we had the -5 -AO drop in mid-February with the record snows in Montreal and Toronto. Similar strong drops in 20-21 and especially March 2018. The We all know about 2010 and the -AO -NAO intervals in 05-06 and of course 95-96. But again not sure about a one to one casual relationship as these features could be markers for another underling process. Perhaps related to the underlying forcing and Rossby wave breaking.

I was able to find one relationship between La Ninas and ACE going back to 1950. Any Atlantic hurricane seasons with 160 ACE or higher like last year tended to have a +PNA December. Now I am not sure if there is any type of causal relationship involved. Could just be a marker. What I mean by this is that the high ACE and +PNA December are part of the same underlying process. It also worked out that the October MJO indicator also was reliable in 2017, 2020, and 2024. So the MJO is also part of the same underlying process at least in more recent years. Those years featured a MJO 5 above +2.70 in October before the December strong +PNA La Ninas mismatch. Atlantic hurricane season ACE above 160 and December +PNA during La Ninas 2005….245 ACE…..+1.38 …..December PNA 1995……227………….+0.92 2017……224…………..+0.89…..October MJO 5….+3.35 1950……211……………+0.02 1998……181……………-0.09 2020…..180…………..+1.58…..October MJO 5…..+2.81 1999……176………….+0.21 2010…..165…………..-1.78….+1.25 +PNA delayed until January 2024…..161………….+1.70….October MJO 5…….+2.76

JFK has a shot at their first 80° July since 2010. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jul Click column heading to sort ascending, click again to sort descending. 1 2010 80.7 0 2 2011 79.8 0 3 2013 79.5 0 4 2025 79.3 6 - 2022 79.3 0 - 2020 79.3 0 5 2019 78.8 0 6 1999 78.7 0 - 1993 78.7 0 7 2016 78.6 0 - 1983 78.6 0 - 1949 78.6 0 8 2015 78.4 0 - 2012 78.4 0 9 1994 78.1 0 10 1955 78.0 0 11 2024 77.8 0 - 2023 77.8 0 - 2002 77.8 0 12 1995 77.7 0 13 1952 77.6 0 14 2008 77.3 0 - 1981 77.3 0 15 1971 77.2 0

Stronger ridge now so the heatwave has been extended to Wednesday.

It’s the first time this summer that the GFS is running warmer than the Euro. The GFS has 100° heat from Monday to Wednesday. But the Euro only gets to 100° on Wednesday.

Unfortunately, the upcoming heatwave looks like another where the urban corridor will be 90° at 11pm after getting near 100° during the day.

Yeah, easily the worst air quality of July so far here just east of HVN. Jul 26, 11:20 am 84 61 45 84 NE 8 4.00 Haze