bluewave

It was the warm storm tracks from Philly to Boston that resulted in the very low snowfall. Very strong Southeast ridge and Pacific Jet on the days when most of the precipitation fell. This has been the main theme since 2018-2019.

The much below average snowfall forecast from the seasonal models run during the fall of 2024 from Philly to Boston did work out. They even got the very low snowfall correct for Chicago. That’s what most on here follow anyway. A continuation of the warm storm tracks through the Great Lakes theme.

It’s good to see some areas doing this well with these big Pacific Jet extensions in recent years. Looks like the strong -IOD forcing lead to the jet extension and wave breaking event. Record warmth in Western Canada with record high 500mb height anomalies. Then the record low 500mb heights over the Western Great Lakes leading to the very early snowfall.

The Great Lakes snowbelts continue to be the best spots for snow in recent years.

Same summer pattern with heaviest rains staying just inland from the coast with .39 here.

Too bad we don’t currently have the technology to determine the exact timing for the break up of the WAIS. Since it could lead to an unexpected faster sea level rise. More rapid melting at some point in the coming decades could become one of the big stories even for people that don’t pay much attention to the warming climate. https://www.nature.com/articles/s41586-025-09349-5 Human-caused climate change worsens with every increment of additional warming, although some impacts can develop abruptly. The potential for abrupt changes is far less understood in the Antarctic compared with the Arctic, but evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment. A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss. A marked slowdown in Antarctic Overturning Circulation is expected to intensify this century and may be faster than the anticipated Atlantic Meridional Overturning Circulation slowdown. The tipping point for unstoppable ice loss from the West Antarctic Ice Sheet could be exceeded even under best-case CO2 emission reduction pathways, potentially initiating global tipping cascades. Regime shifts are occurring in Antarctic and Southern Ocean biological systems through habitat transformation or exceedance of physiological thresholds, and compounding breeding failures are increasing extinction risk. Amplifying feedbacks are common between these abrupt changes in the Antarctic environment, and stabilizing Earth’s climate with minimal overshoot of 1.5 °C will be imperative alongside global adaptation measures to minimise and prepare for the far-reaching impacts of Antarctic and Southern Ocean abrupt changes.

Looks like a back and forth pattern setting up this month. Next chance for low 90s at the usual NJ warm spots Friday into Saturday. Then cooler weather returns for next week with a warm up again in mid-September.

The big story in the Arctic last few summers has been the record warmth in the Kara and Barents seas areas with the very low sea ice extent there. https://alaskaclimate.substack.com/p/august-2025-arctic-sea-ice Regional Sea Ice The Atlantic side of the Arctic has had very low ice extent all summer, with the Barents and Kara Seas almost entirely open water for much of late July and August. The pack ice edge at the end of August was near 82N, 200 km or more north of the Svalbard and Franz Josef Land archipelagos. The climate impacts of the lack of ice were dramatic. The only real-time climate station in Franz Josef Land, Polargmo Im. E. T. Krenkelja on Heiss Island at 80.6N, did not record a temperature below freezing in August. At Wiese (Vize) Island, a small island in the northernmost Kara Sea at 79.5N, the temperature has remained above freezing since July 16 (47 days as of September 2). Last summer, the longest freeze-free period there was 11 days and in summer 2023 the longest was only 4 days. On the Pacific side of the North Pole, ice loss in the Beaufort Sea increased during August, but plenty of ice remained at the end of the month in the eastern part of the basin. The Northern Sea Route, along the north coast of Russia, was open to most vessels by late August. The Northwest Passage, connecting Canadian waters with the Bering Strait, was close to being open for non ice-hardened traffic, but mobile areas of higher concentration ice persisted at the end of August in Amundsen Gulf, the southeastern-most portion of Beaufort Sea.

The one lucky thing about that hurricane is that the surge occurred at low tide. So the actual tide level was similar to Sandy. But the surge was higher than Sandy which happened right at high tide. The rapid forward motion of the hurricane allowed the water level at the Battery to rise 13 feet in around an hour. Can’t even imagine what that would have been like in the era before weather forecasts. https://www.nature.com/articles/srep07366 While Hurricane Sandy was record breaking compared to published tide gauge records, earlier historical accounts suggest that a major hurricane in 1821 CE may have had a similar storm tide and a substantially larger storm surge5,7. During this 1821 hurricane the New Bedford Mercury newspaper reported a rise in water of 13 feet 4 inches or 4.06 m above low water in the East River4,6. The 1821 hurricane struck New York City at low tide with roughly 4.0 to 4.1 m of storm surge, compared to Sandy's 2.8 m of storm surge. Assuming this account is referenced to near the Battery, a 4.0 m storm surge would far exceed all events recorded within the instrumental tide gauge record, including Hurricane Sandy. Other flood descriptions support the 1821 hurricane as a significant flood event, including a 10 foot (3.0 m) rise in water level at Pungoteague, VA5, drift caught in the trees 9 feet (2.7 m) above the ground at Cape May, NJ5 and a tide several feet above normal at New London, CT6. Because peak flooding for the 1821 hurricane occurred at low tide, its storm tide was smaller than its overall surge. Ref. 7 estimated a storm tide of roughly 3.2 m for the event, which is slightly less than that observed for Hurricane Sandy at 3.4 m.

This is the strongest -IOD since the 22-23 and 16-17 La Ninas. My guess for the rest of this season is that the ACE will finish below the 161 level of last year. But we have to watch for a rebound in hurricane activity from mid to late September right into October which has been common since 2012.

Strongest -IOD in 3 years.

Looks like Friday into Saturday will be our next chance for 90° heat at the usual warm spots. Could be some scattered convection with the cold front. But should become cooler and drier into next week as Canadian high pressure dominates again.

First two consecutive years with a quiet Labor Day weekend following a Cat 5 hurricane.

It comes out before the NOAA maps but has been reasonably close based on recent experience to what the NOAA updates have been. The state of PA had their 3rd warmest June and July period on record at 71.8°. The summer ranking will be lower when NCEI updates in a few weeks since August was cooler.

It will probably come down to frontal timing. The GFS has 90° on Friday for the warm spots in NJ. The Euro has a slightly slower frontal passage so the 90° on Saturday. Won’t take much to beat guidance by a few degrees with how dry it has been.

The August maps won’t update for several more days on that site. But the summer maps on some other sites that have updated are the same pattern. Warm in the East and West with cooler in the middle. The prism maps already updated for JJA with numerous top 10 warmest summer rankings for the Northeast.

The main reason I use it is that my analysis and forecasts are based on the perspectives. So I need to compare it to what has happened in the period of record. But I understand that many seasonal forecasts are 1991-2020 departure based on where the areas of above and below temperatures are located. My guess from several years back that our next colder winter would only be colder relative to the much warmer 1991-2020 baseline worked out. As this past winter in the Northeast would have been slightly warmer based on earlier periods of record. DJF 2024-2025 Northeast 24.6° 1895-2000….+1.4° 1961-1990……+1.8° 1971-2000……+0.5° 1981-2010…….-0.3° 1991-2020……-1.2°

My area along the CT Shoreline finished with the 2nd highest number of 90° days at 15. The high of 98° in June set the new monthly all-time high by +2°. Overall the summer was the 4th warmest here with many top 10 warmest in recent years. So I was very grateful for the much cooler temperatures to end the summer. The low of 51° was the 7th coldest for the month of August. The drop from the record high dewpoints earlier in the summer really helped out. Time Series Summary for NEW HAVEN TWEED AP, CT - Jan through Dec Top 10 highest 90° days Click column heading to sort ascending, click again to sort descending. 1 2022 17 0 2 2025 15 121 3 2010 14 0 4 1977 13 100 5 2021 12 0 - 2020 12 2 - 2012 12 3 6 2013 11 0 7 2002 10 3 - 1952 10 0 8 2024 9 1 9 2023 8 1 - 2019 8 2 - 2018 8 3 - 2016 8 0 - 1955 8 0 10 2011 7 0 Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Jun Highest monthly max temperature Click column heading to sort ascending, click again to sort descending. 1 2025 98 0 2 1957 96 0 3 2012 95 0 4 2021 94 0 5 2008 93 0 - 1974 93 0 - 1964 93 0 - 1953 93 0 - 1952 93 0 6 2024 92 0 - 1968 92 0 - 1966 92 0 - 1956 92 0 - 1949 92 0 7 1965 91 0 - 1963 91 0 8 2022 90 0 - 2020 90 0 - 2019 90 0 - 2013 90 0 - 2010 90 0 - 2003 90 0 Time Series Summary for NEW HAVEN TWEED AP, CT Top 10 Warmest Summer Click column heading to sort ascending, click again to sort descending. 1 2022 75.4 0 2 2024 75.2 0 3 2020 74.9 2 4 2025 74.5 0 5 2010 74.3 0 6 2021 74.2 0 7 2019 74.0 0 8 1977 73.8 31 9 2018 73.6 0 10 2012 73.5 0 Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Jun Click column heading to sort ascending, click again to sort descending. 1 2024 72.9 0 2 2025 71.8 0 3 1976 71.4 0 4 2021 71.3 0 5 2010 71.0 0 6 1977 70.9 23 7 2008 70.8 0 8 2020 70.1 0 9 1957 69.9 0 10 2013 69.7 0 - 1949 69.7 0 Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Aug Top 10 lowest monthly minimum temperature Click column heading to sort ascending, click again to sort descending. 1 1976 43 0 2 1965 45 0 3 1952 46 0 4 1964 48 0 - 1957 48 0 - 1956 48 0 - 1949 48 0 5 1971 49 0 - 1968 49 0 - 1948 49 0 6 1955 50 0 - 1953 50 0 7 2025 51 0 - 2006 51 0 - 2004 51 4

JJA 2023 was actually a little warmer against the long term averages. But since 2010-2025 has been so warm it felt cooler. You can see how this summer matched the 2010-2024 pattern with warmth in the East and West with cooler in the mid section of the nation. This is the same way that this winter felt colder by comparison to the much warmer winters since 15-16. But it was still warmer than the long term average in the Northeast.

Even with this cooler ending to August, it was still another top 10 warmest summer for many locations. This has been the case most summers since 2010. Plus the all-time June heat in the 100° to 105° range. So it was very nice to get a relaxation of this heat during August. The cooler conditions in May and August into the start of September prevented the warm spots from making a run on 50 days reaching 90° like 2022 and 2010. So we got lucky that the heat peaked early again in June and July. The Erin Cat 5 recurve and other wave breaks helped pull the trough into the East during recent weeks. My area actually ranked higher for 90° days this year than the warm spots like Newark. Time Series Summary for NEW HAVEN TWEED AP, CT - Jan through Dec Top 10 years 90° days Click column heading to sort ascending, click again to sort descending. 1 2022 17 0 2 2025 15 122 3 2010 14 0 4 1977 13 100 5 2021 12 0 - 2020 12 2 - 2012 12 3 6 2013 11 0 7 2002 10 3 - 1952 10 0 8 2024 9 1 9 2023 8 1 - 2019 8 2 - 2018 8 3 - 2016 8 0 - 1955 8 0 10 2011 7 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Top 10 years 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 2025 38 122 8 2005 37 0 - 1987 37 0 9 2018 36 0 - 1949 36 0 10 2015 35 0

We had a top 10 warmest summer here in the Northeast at many locations. Also top 10 for 90° days during the summer and 70° summer minimums along with record high dewpoints. Several spots also had a top 10 driest summer. All-time heat for June with several spots in the 102-105° range which was a first for the month of June. We have seen this theme frequently during the 2020s. Heat peaking earlier in the season and relaxing a bit relative to the early season during August some years like this one. Familiar new pattern this decade with summer heat in the West and East while cooler in the middle of the nation. For the period from 2010 to 2025 the Northeast has experienced 13 out of 16 warmer to record wam summers. Most summers have finished somewhere in the top 10 for warmth over this period. The last cooler summer relative to earlier periods was in 2014. But we haven’t had a significantly cooler summer relative to the past since 2009. That was our last top 10 coldest June into July period.

Started seeing some wave breaking activity right around the time we had the big cat 5 recurve with Erin a few weeks ago. So this helped to reinforce the cooler trough pattern in the East. It’s been nice having the trough in the Northeast from late August into early September following the record June and July heat. The record low pressure north of Alaska may have been a part of this pattern.

Yeah, numerous top 10 driest summer reports in the Northeast.