bluewave

It’s tough when Canada is having record heat and drought and they keep getting all these lightning strikes. https://www.cbc.ca/news/canada/british-columbia/bc-wildfires-1.7599568 BC’s fire season is surging as the number of active wildfires more than doubled from 61 on Thursday to 134 by Friday morning, according to the B.C. Wildfire Service (BCWS). The service says the surprising increase in fires can be attributed to the more than 35,000 lightning strikes on July 30 and 31 — with even more expected, as severe thunderstorm watches remained in place on Friday for a large swatch of the southern Interior and stretching into locations in the northeast.

2nd worst air quality in the world for Toronto following the smokiest July on record in Winnipeg.

The most significant cold in my area over the last decade was 12-26-17 to 1-8-18. It was mostly Pacific driven. This is why my comment about other factors having a greater influence on the Northeast temperatures than the NAO. You can see the generally lower heights over Greenland to Iceland. The best blocking was over Western North America. Time Series Summary for NY CITY CENTRAL PARK, NY 10 coldest 12-26 to 1-8 periods on record Click column heading to sort ascending, click again to sort descending. 1 1918-01-08 13.4 0 2 2018-01-08 17.9 0 3 1904-01-08 20.6 0 4 1881-01-08 21.9 0 5 1879-01-08 22.2 0 6 1887-01-08 22.4 0 7 1981-01-08 23.7 0 8 1940-01-08 23.9 0 9 1968-01-08 24.2 0 10 1877-01-08 24.6 0

More spots in the CONUS finished with below average snowfall than above average snowfall for the 24-25 season.

You can always find a random spot that does well with snowfall even though the overall CONUS snowfall was below average last winter.

Not as much correlation between the NAO and Northeast temperatures over the last decade or so. February 2015 was our last really cold month and one of the strongest +NAOs. It’s really how the higher latitude teleconnections blend with the subtropical patterns which determine our sensible weather around the Northeast. While you might not consider the changes great, shifting a gradient only hundreds miles north will have a big effect on snowfall and temperatures near where the gradient used to set up. But if you are far enough north and the gradient is still to your south than it isn’t a big deal for you.

Last February was out best -WPO in years but its influence was muted by the stronger subtropical ridge forcing the gradient too far north.

Never said they are ineffective. But the effective gradient does shift north from where it has been. This is why some areas over the Great Lakes and interior Northeast north of the gradient have done better in the snowfall department than the coastal plain.

I fully understand. We all came up in the era when the higher latitude teleconnections ruled the roost and the mid-latitudes generally followed that lead. But we have been seeing more influence from these subtropical ridges over the last decade. So the nuisance you mention is recognizing the larger role for the mid-latitudes. So sometimes the ENSO and higher latitudes take more of a back seat. But everything is having some influence so we can tie together these multiple threads into one coherent pattern.

Looks like a really nice August pattern through the weekend. The warmest departures will miss to our north with onshore flow here. A few warmer days in the low 90s but nothing too extreme. Then other days with the highs in the 80s. Pattern looks pretty dry through at least next weekend. The one negative will be all the smoke from the record Canadian wildfires.

The higher latitude ridge near Greenland was not any more further north than in the past when had KU snowstorm tracks as the comparison to 2014 snowed. But what changed is that the subtropical ridge was too far north. So the gradient got pushed to our north with the heavy snows.

Last February would have been a much better pattern for the area around NYC if this mid-latitude ridge from Hawaii to Bermuda wasn’t so overpowering. It muted the -EPO -WPO and Greenland block influence. Back in February 2014 the -WPO-EPO and Greenland block was able to dominate so it was much snowier around NYC. February 2025 had the first -5 AO and -5 SD Greenland block cutter that gave record snows to Toronto and Montreal instead of around NYC Metro.

I wouldn’t say the +AO is driving it since the ridge in the North Pacific beneath the -EPO and ridge north of Alaska is even stronger than the one we just had under the +AO in the Northeast. We have seen the ridge in the Northeast with the record -5 AO back in February. So while the higher latitude teleconnections shift around, this mid-latitude ridge has been the one constant.

Whatever we decide to call it, this June and July featured the strongest continuous 40N mid-latitude ridge from Japan across the U.S. and North Atlantic to Europe that we have seen before. It’s what’s ultimately driving these record -PDO values and record warmth around the Northeast this summer. This ridge has been much stronger than we have ever seen from past La Ninas or -PDO patterns.

It was only the 2nd 80° behind 2010. But it felt warmer this time around since the dewpoints were so much higher. The average max finished just behind 2010. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY June 21st through July 31th AVG Temp Click column heading to sort ascending, click again to sort descending. 1 2010-07-31 80.7 0 2 2025-07-31 80.0 0 3 2020-07-31 78.5 0 4 2013-07-31 78.4 0 - 2011-07-31 78.4 0 5 2012-07-31 78.2 0 6 2019-07-31 78.1 0 - 1949-07-31 78.1 0 7 2016-07-31 78.0 0 8 2024-07-31 77.6 0 - 2015-07-31 77.6 0 - 2002-07-31 77.6 0 9 1993-07-31 77.5 0 10 2022-07-31 77.4 0 - 1999-07-31 77.4 0 - 1983-07-31 77.4 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY June 21st Through July 31st Max AVG Temp Click column heading to sort ascending, click again to sort descending. 1 2010-07-31 89.2 0 2 2025-07-31 87.6 0 3 2011-07-31 86.5 0 4 2019-07-31 86.3 0 - 1966-07-31 86.3 0 5 2012-07-31 86.1 0 - 1963-07-31 86.1 0 - 1949-07-31 86.1 0 6 2020-07-31 86.0 0 7 2002-07-31 85.9 0 8 2013-07-31 85.6 0 9 1993-07-31 85.5 0 10 2016-07-31 85.3 0 - 1983-07-31 85.3 0

Yeah, being driven this time by record mid-latitude 500mb ridges warming the SST anomalies to +15 near Japan.

I was talking about this early part of the month right in front of us. It will get warmer again once the big high pressure shifts off the east coast in mid-August. So my guess is that August will finish with above average temperatures.

It’s based on the peak MJO 5 amplitude in October during multiyear La Ninas. La Ninas with MJO 5 peaks over +2.70 in October had the stronger +PNA from December into January. But it usually only happens once during each multiyear La Niña. This most recent La Nina in 24-25 had the MJO 5 peak last October over +2.70. So the +PNA from December into January was at record levels for a La Nina. NOAA coined the phrase mismatch in their blog when La Ninas have strong +PNA patterns rather than -PNA. The 20-21 to 22-23 multiyear La Ninas had the most amplified MJO 5 in October 20. So the strongest Dec-Jan +PNA during that 3 year La Niña occurred in 20-21. The other 2 La Nina’s were more -PNA. But there were still several +PNA intervals during this winters. During the 16-17 to 17-18 two year La Niña the strongest MJO 5 in October occurred in 17. Dec-Jan 17-18 had a better +PNA than Dec-Jan 16 did. So based on this pattern over the last decade, my guess is that the MJO 5 will be weaker this October than last year. But I want to wait for the actual verification to make that call for sure. My early guess for next winter is that it will be warmer than last winter was with the PNA index less positive than last winter was. But since the snowfall was so low anyway, it wouldn’t take much for one snowstorm to potentially equal or exceed last winter around NYC Metro.

All Newark needs to have another year with 40 days reaching 90° is to approach the 2010-2024 average of 11 days after July 31st. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Most 90° Days Click column heading to sort ascending, click again to sort descending. 1 2010 54 0 2 2022 49 0 - 1993 49 0 3 1988 43 0 4 2021 41 0 - 2002 41 0 - 1991 41 0 5 2016 40 0 - 1983 40 0 - 1959 40 0 6 1994 39 0 - 1944 39 0 7 2005 37 0 - 1987 37 0 8 2018 36 0 - 1949 36 0 9 2015 35 0 10 1961 34 0 11 2024 33 0 - 2012 33 0 - 1999 33 0 - 1995 33 0 - 1966 33 0 12 1955 32 0 - 1953 32 0 - 1943 32 0 13 2020 31 0 - 2011 31 0 - 1973 31 0 - 1952 31 0 14 2025 30 151 Monthly Number of Days Max Temperature >= 90 for NEWARK LIBERTY INTL AP, NJ AVG 90° days Aug to Oct Since 2010 Click column heading to sort ascending, click again to sort descending. Mean 8 3 0 11 2024 7 0 0 7 2023 5 6 0 11 2022 18 1 0 19 2021 13 1 0 14 2020 9 0 0 9 2019 4 3 1 8 2018 14 4 0 18 2017 2 3 0 5 2016 13 5 0 18 2015 13 5 0 18 2014 2 3 0 5 2013 3 1 0 4 2012 7 2 0 9 2011 4 0 0 4 2010 11 6 0 17

Updating for July 2025 with several spots in NJ approaching and exceeding 10 inches of rain for the month. Monthly Data for July 2025 for New Jersey Click column heading to sort ascending, click again to sort descending. AEROFLEX-ANDOVER AIRPORT WBAN 16.54 HOWELL TWP 3.7 SSW CoCoRaHS 12.87 JACKSON TWP 4.9 ENE CoCoRaHS 12.22 MANASQUAN 1 NW COOP 9.75 WALL TWP 2.5 ENE CoCoRaHS 9.58 NORTH BRUNSWICK TWP 1.5 W CoCoRaHS 9.28 STAFFORD TWP 2.8 NNW CoCoRaHS 9.26 MANASQUAN 1.0 WNW CoCoRaHS 8.96 WOODBRIDGE TWP 3.0 NNW CoCoRaHS 8.76 GREEN BROOK TWP 0.9 S CoCoRaHS 8.60 CLARK TWP 0.7 SSW CoCoRaHS 8.58 HAMILTON TWP 4.5 NW CoCoRaHS 8.53 LONG HILL TWP 1.8 WSW CoCoRaHS 8.52 CLARK TWP 1.3 ENE CoCoRaHS 8.44 NEW PROVIDENCE 0.8 ESE CoCoRaHS 8.41 EDISON TWP 1.9 N CoCoRaHS 8.33 NEPTUNE CITY 0.1 E CoCoRaHS 8.22 Atlantic City Area ThreadEx 8.08 ATLANTIC CITY INTL AP WBAN 8.08 WESTFIELD 0.8 WSW CoCoRaHS 8.06 SOUTH BRUNSWICK TWP 3.1 NW CoCoRaHS 7.77 NEW BRUNSWICK 3 SE COOP 7.69 New Brunswick Area ThreadEx 7.69

Sad to see so much flood damage in Bayside, Queens.

This is going to be the best first week of August weather we have seen in years. Very impressive Canadian high pressure will dominate. The easterly flow will keep the temperatures comfortable for this time of year with a break in the record heat that we experienced from late June through July. The high pressure will keep most of the rain to our south.

Yeah, we would get smaller Canadian wildfires back in those days. We even had smoke in the late 80s from wildfires in the Appalachians. But the Canadian wildfires have been at record levels since 2023. June 6-8, 2023 was a first for our area having such thick smoke. A recent study found that the smoke dropped our temperatures by 5°F. https://www.rmets.org/metmatters/worst-air-quality-world-wildfire-smog-smothers-new-york The Wednesday morning air quality was bad. The day began in the “red” with AQIs in the 151-200 range. An AQI in that range has only occurred a handful of times in the last few decades in the city. Still, New Yorkers tried to continue with their daily routine activities. By late Wednesday morning, the grey blob as seen from the ABI visible band on GOES satellite, showed the highest concentration of smoke flowing across Lake Ontario, Upstate New York and into the City region. Shortly after, the skies went dark over the city by 2pm, and air quality continued to worsen through the evening. The AQI was above 480 on Wednesday evening in NYC, technically off the chart. NYC’s air quality was quickly compared to large cities in India and China known for their chronic pollution. At that point, New York City had the worst air quality in the world. The pollution was bad enough to cancel outdoor after-school activities for the 1.1 million students in the largest public school system in the country, and prompt a shift to remote learning for the following days. https://rmets.onlinelibrary.wiley.com/doi/10.1002/asl.1306?af=R#:~:text=During the fire season of,(NYC) and its surroundings. https://www.nature.com/articles/s43247-025-02214-3

We have seen this 2025 pattern in recent years during 2021 and 2017 when the highest temperatures of the year occurred in June. The most recent heatwave peaked several degrees lower. So based on past statistics, the best chance for Newark to see 100° heat in August has been before August 15th since 1994. 1993 was the last time Newark reached 100° after August 15th. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Years with 100° days after August 15th Click column heading to sort ascending, click again to sort descending. 1 1953-10-31 105 0 2 1948-10-31 103 0 3 1881-10-31 101 2 4 1993-10-31 100 0 - 1973-10-31 100 0 Dates of all August 100° heat at Newark since 1994 8-1-24…100° 8-9-22..101° 8-3-06..101° 8-13-05…102° 8-13-02…100° 8-9-01…..105°

These summer days under 80° have become a rarity over time.