bluewave

Yeah, June and July 2009 were both very cool and wet summer months around the area. It was the 2nd coldest June-July period on record at LGA. Recent years have had numerous top 10 warmest. This June and July was +6.1° warmer at LGA than 2009 was. The same period back in 2020 was a full +8°warmer. Time Series Summary for LAGUARDIA AIRPORT, NY Top 10 Coolest June 1st through July 31st Click column heading to sort ascending, click again to sort descending. 1 1972-07-31 70.3 0 2 2009-07-31 71.4 0 3 1982-07-31 71.6 0 4 1978-07-31 71.9 0 5 1969-07-31 72.0 0 - 1947-07-31 72.0 0 6 1958-07-31 72.3 0 7 1940-07-31 72.5 0 8 1946-07-31 72.6 0 9 1985-07-31 72.7 0 - 1975-07-31 72.7 0 - 1950-07-31 72.7 0 10 2000-07-31 72.9 0 - 1974-07-31 72.9 0 Time Series Summary for LAGUARDIA AIRPORT, NY Top 10 Warmest June 1st through July 31st Click column heading to sort ascending, click again to sort descending. 1 2020-07-31 79.4 0 - 2010-07-31 79.4 0 2 1994-07-31 78.1 0 3 1999-07-31 78.0 0 4 2024-07-31 77.9 0 - 2008-07-31 77.9 0 5 2013-07-31 77.7 0 6 2025-07-31 77.5 0 7 2016-07-31 77.4 0 - 1966-07-31 77.4 0 8 1952-07-31 77.3 0 9 2019-07-31 77.2 0 10 2006-07-31 77.1 0

Yeah, I enjoyed the really cool summers growing up in Long Beach that we would get every few years. That 2010 summer really reset our whole summer pattern to much warmer. 2009 was the last time we had a cool summer here. While 2014 was our last comfortable summer, it didn’t really make it to the 2009 level of coolness. 2009 was the last top 10 coolest June and July which was the coolest since the 1940s. As the recent less warm summers like 2023, 2017, and 2014 were a function of the much warmer summer climate normals. Those were still a little warmer than the long term average. Plus 2023 and 2017 still had between 15-20 days at places like JFK with a 75° or greater dew point. So those very high dew points worked against the cooler and lower humidity summers of the past.

July was the strongest Southeast ridge on record for the month from NYC to ATL. This beats the previous record July 500mb heights set back in 1952. But the difference this time is that we had a +0.74 PNA for July. While July 1952 had a -1.23 PNA. So we continue to see these disconnects between the higher latitudes and mid-latitudes. This disconnect is why the Euro still has a Southeast ridge into next winter while also having a -EPO and +PNA.

Right on cue the pace of Arctic sea ice loss has slowed behind the 2012 record drop experienced in early August 2012. That was at the end of an historic Arctic Dipole pattern from 2007-2012 leading to all the records over that 6 year period. This season so far has continued the much weaker Arctic Dipole pattern since 2013. So this changed summer Arctic circulation pattern since then has resulted in no sea ice trend since those steep declines. But the Arctic has seen increasing warmth over this period. So even with these more favorable conditions for Arctic sea ice retention, the sea ice thickness and extent has not returned to the pre 2007 state. Most Septembers finish between 4-5 million sq km over this period well below the major Arctic shift in 2007. I mentioned the melt pond data from early in the season which is one of the early indicators to look at. But this was the first year it hasn’t been published online. It probably would have shown something near the middle of the pack based on the lack of strong warmth this May. This was the opposite of the strong preconditioning in 2012 and 2020. 2012 was a perfect storm of a strong Arctic Dipole pattern following significant May preconditioning and the record Arctic cyclone in early August. These three features have not occurred in tandem since then. Special thanks to Gerontocrat from preparing the current extent which is in 7th place and 593K higher than 2012 as of August 9th. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024GL114546

The story of this summer and much of the last decade has been the models underestimating the WAR or SE Ridge beyond 5 days. So this has been a repeating model forecast error. Around August 1st the forecast for August 11-18 had a modest warm up into the 90s. Definately a rebound from the less warm pattern this week. But now much of the guidance brings back 100° potential again. So you can see this big shift in the models in just 5 days of runs. New run August 11-18 Old run

Looking like models want to bring back the 100° heat for spots like Newark next week before the 15th. Be interesting to see if this matches recent history since 1994 of no 100s after August 15th. But wouldn’t be surprised if we eventually end up getting late August into early September 100° heat again. Especially since the model runs over the last 5 days have really dried out the forecast pattern again after the locally flooding rains last week. Not a great precedent to set for this much warmer climate if we can continue to reload 100° heat following these flash flood events. Past instances of these flooding events usually came after the 100s and we didn’t get follow up 100s. I was thinking as recently as a few days ago that maybe only a few warm spots in NJ could challenge 100° again. But the latest guidance is suggesting that 100° heat could also be possible in places like Queens. So unfortunately we may be entering an even warmer phase of these already warmer to record warm summers since 2010. The posters that were suggesting that we could see a mid-August heatwave at least rivaling the one back in late July may turn out to be correct. Good call on your part.

2009 was the last time that we had both a cool September and October.

Very impressive storm for this time of year with such a strong +NAO vortex.

Yeah, unfortunately that storm track inland from the East Coast has become a persistent feature since 18-19. Plus we have seen some version of a highly amplified North Pacific ridge most years since 16-17. Some years the ridge axis lines up more with the Aleutians and other years it’s closer to the West Coast. Either way we never miss an opportunity for the Southeast ridge to overperform especially near storm time.

Pretty funny. But the Euro has never shown a +5 anomaly in the Northeast from a seasonal forecast issued in the summer or fall. While we have had numerous warm anomalies near that magnitude since 15-16. If seasonal models can get at least one or two elements correct with a seasonal forecast, then we should be happy. I think the JMA back in October 2013 was the last time one of these seasonal models really hit it out of the park.

I think the last time the Euro seasonal had reasonably good winter forecast from October was 21-22. The forecast from August 21 was a miss. During the October forecast it got the idea of the -PNA correct for December. But the magnitude of the warmth and -PNA depth was way underdone. Probably related to the inability to correctly model the MJO beyond 1-2 weeks out. Then the January forecast was a miss since the MJO 8 wasn’t forecast beyond the late December period. February was reasonably close. Plus the 3 month mean blended together was OK. It wasn’t a mismatch type winter so it didn’t throw the seasonal off like we got last October which we were discussing last year. So probably just wait until we see how the October MJO indicator works out and what the model shows at that point.

The Euro seasonal is going with a delayed start to fall which has become common in recent years.

Just wondering were the seasonal model error will actually be during the winter since we seldom see perfect forecasts from any of the models from this range.

If something resembling that pattern verifies, then elevation and higher latitude will be your friend in the Northeast like we have seen during recent seasons.

I am just commenting on what the model is showing. It’s striking how similar it is to the 500mb pattern we are getting this summer. If we do get a pattern resembling that next winter, then maybe the worst in terms of those strong -PNAs like we had in 21-22 and 22-23 is behind us. But it looks like the model still wants to go with the storm track through the Great Lakes which has been persistent since 18-19.

The Euro has an active storm track through the Great Lakes for the crew in the favored lake effect snow zones.

Yeah, very similar. It goes to the comments I made earlier. There is a disconnect between the higher latitude teleconnections and the mid-latitude pattern. So we still get the subtropical ridge from the Pacific across the U.S. and Atlantic even with the -EPO +PNA.

The Euro has the same winter pattern at 500mb as we are getting this summer. It’s a -EPO +PNA and Southeast Ridge pattern. Pattern persistence or the model is in repeater mode? Stay tuned….

I think the Pacific will continue to be much more important than what the NAO does. The last time we saw a few KU events was back in January 2022 with a solid +NAO pattern. The key was the strong MJO 8 which allowed the Pacific Jet to relax for a month. That was the last time many of us had a cold and snowy month. So we would want to see improvement from the Pacific Jet.

Yeah, we used to do many boat trips across the back bays in Nassau. It’s a whole new world to explore out on the water. The bay houses are fun to see in person rather than at a distance from the shore.

The magnitude of the heat and drought in Canada is much more extensive this time around as the climate continues to warm. Those past events you referenced were normal occurrences back in the colder and more stable climate of the past. What has been occurring in Canada since 2023 is a whole new ballgame. First, we had the historic 500mb ridge over Canada in May 2023 leading to the historic wildfire outbreak and record smoke pollution in places like NYC. This standing wave which drove the drought and fires was related to record warming in parts of the Pacific which helped to lock in the record heat and 500mb ridging in Canada from 2023 to the present. Second, the current global political system is not capable of dealing with all the cascading effects of this rapid warming. So the response will have to be more driven by informed individuals that can make their own personal decisions on how to respond to this new climate.

You are looking at the global temperature jump in linear terms. First, what seems like a small rise in average global temperatures has much more amplified effects regionally. Second, SSTs in some tropical and even subtropical zones areas can cross a threshold where a nonlinear shift occurs. Resulting in standing waves that remain stationary for extended periods leading to very high local to regional warm departures. Unfortunately, there isn’t a guide we can consult which has a set SST level at which the changes will occur. As the climate is warming faster than our modeling technology can keep up with. So many of these shifts are only realized after the fact.

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