bluewave

The winter pattern this year wasn’t a surprise to me since I was discussing the +PNA mismatch potential last October in this thread. At least that portion of what happened related to the October forcing continuing into winter followed the past occurrences which I already outlined numerous times earlier in this thread. But the Pacific Jet did not relax as in earlier years with +PNA La Ninas from December into January. This was my reference last October to other factors not lining up the same way so the outcomes could be different this year. You seem to be agreeing with what I have said numerous times in regard to departures. This winter for many around the northeast was only average temperature wise. Since the small -1 departures were only average based on earlier climo from 1981-2010. This is why I use the actual temperatures and not the departures. As the bar for colder departures naturally gets lower as the means keep rising for each 10 year update. This winter was the warmest on record for my area compared to similar -EPO +PNA -AO patterns which have occurred in the past. So the magnitude and duration of the cold was lesser than past instances which had these 500mb patterns. As this was one of the warmest winters on record across the Northern Hemisphere. This along with the strength of the Pacific Jet and other teleconnections prevented a cold and snowy outcome like we saw in the Northeast in 13-14. It’s why I didn’t buy the analogs mentioning a 13-14 repeat that were being posted on twitter. It’s also not controversial to recognize that Arctic outbreaks cover less territory in a rapidly warming world. And the places that do get the coldest aren’t as widespread as they used to be in a colder world. So when the U.S. was having its Arctic outbreaks, the geographic footprint was greatly reduced compared to the past. The cold tended to focus more in smaller regions and not pushing into the Northeast. The cold concentrated in pockets focused to our south and west like we saw with the January 2019, and February 2021. This is why top 10 and 20 warmest months greatly outnumber top 10 and 20 coldest. You say that this wasn’t a cutter pattern, yet we had one of the most intense February cutters on record several weeks ago with high winds across the Northeast and heavy rains. The storm track was so warm that it was the first time in the Northeast with a -5 -AO and +500 meter Greenland block. As the past instances saw cold suppressed tracks or historic NYC blizzards instead. You obviously didn’t read my earlier posts about the long term snowfall history and changes which have been occurring over the last 60 years. So you seem to be editorializing on some talking point that you read from someone else. Obviously, lake effect snow has been doing great as I have pointed out with the storm track patterns and record Great Lakes warmth leading to delayed freeze-ups. The reason that NYC and surrounding areas had well below normal snowfall was due to the fact that the storm tracks continued to be warmer than average like we have seen for much of the last 7 winters. This is why I pointed out that the actual winter average temperature was significantly cooler than on the days that the precipitation fell. So it was too warm on the days that the precipitation fell for much snow. Go back and read my last few posts in this thread outlining the importance of the actual temperatures on the days that the precipitation falls rather than what the winter average temperature was.

I never said that a benchmark snowstorm pattern was a thing of the past. But at least around NYC Metro, it’s been a prerequisite for an average to above average snowfall season since the mid 90s. From the early 60s to early 90s we were able to get close to average without having to rely exclusively on benchmark or KU NESIS snowstorm events. So in that colder climate we could still get closer to average with a bunch of smaller or moderate events. This hasn’t been the case for 30 years now. I don’t claim to know how long this cutter, hugger, and suppressed Southern Stream storm track pattern which has dominated since 18-19 will last. Just that we will need a return to benchmark tracks in coming seasons in order to reach average to above average snowfall again. But at the same time, I think it’s unlikely that we will see a repeat of the 9 year historic benchmark KU tracks that dominated from 09-10 to 17-18. It’s funny that even in the one low snowfall year of 11-12, we still managed an historic October snowstorm. So every year had some type of record snowstorm. My hope is that we can see some return to benchmark tracks in the future even if it turns out to be well off the pace we saw in the 2010s. Unfortunately, we don’t have multiyear storm track guidance tools yet. So we have to wait until the winter actually starts to see what the storm tracks look like.

First of all, Boston didn’t have a historically cold winter this year. 31.6° was as close to the 1981-2010 average of 31.8° that you can get. The only reason you finished with a small cold departure was due to the 1991-2020 normals being warmer at 32.5°. This wasn't as cold as the 03-04 winter that you cited that you cited was. The reason for the below average snowfall for your area was a continuation of the warmer storm tracks which have been the pattern since 18-19. The faster Northern Stream of the Pacific Jet has lead to storms cutting to the Great Lakes, others hugging the coast or tracking just inland leading to mixed precipitation events, and tracks getting suppressed too far south due to kicker troughs entering the West as lows are exiting the East Coast. So benchmark storm tracks have been few and far between since 18-19. My analysis isn’t based on theory since I have 60 years of snowfall data around NYC Metro to back it up. When NYC had a more stable and colder climate from the early 60s to early 90s, there were many median snowfall seasons in the 19” to 30” range. These middle of the road closer to average seasons have become few and far between over the last 30 years. They were replaced by most seasons coming much lower or much higher. So a shift to all or nothing type seasons. The last 7 seasons perfectly conformed to this 30 year snowfall distribution pattern. So did the 09-10 to 17-18 pattern. As the winters and or storm tracks continue to warm, this will favor more of the below range type winters. But where we still have to wait for data is to know we will see more of a shift to benchmark storm tracks in the coming winters. This could bring the recent average back closer to 20” around NYC Metro or maybe above for a short interval before dropping back down under 20” with further winter warming. So it’s more of a timing issue rather than a directional one. I will go on record saying that I don’t see a 09-10 to 17-18 historic benchmark snowstorm pattern returning in this much warmer climate. So I stand by may call that the 09-10 to 17-18 was the highest or peak snowfall over a 9 year range that we see around NYC Metro. My guess based on the data is that when we get into the 2030s, it will be clear that 18-19 was the beginning of the snowfall decline. The recent 7 year snowfall average in NYC is 14.9” which is the lowest 7 year mean on record. All previous 7 year slumps were followed by big seasons of 50”+ and winter average temperatures near 32.0° or lower. This has not happened in over a decade with how warm the winters and storm tracks have become. So it will be a challenge meeting those conditions over the next several winters with the warming trend which has become more pronounced over the last decade.

But the under 20” totals during those winters were the result of drier conditions and not being too warm on the days that precipitation fell. This is what sets the most recent 7 year period of low snowfall apart from past low snowfall periods around the NYC Metro region. Snowfall after the 7 year past snowfall slumps always rebounded since they ended with 50”+ snowfall seasons and winters which averaged near 32.0°. NYC hasn’t had either since 14-15. This winter was both too warm on the storm days and the DJF average which was 34.8° to make a run on 50”. So it becomes more difficult to break a snow drought as the climate continues to get warmer around my region. My guess is that the snowfall around NYC Metro region peaked during the 2010 to 2018 era and has begun a longer term decline since 2018-2019. The only question is if we can see a few closer to normal or above normal snowfall seasons along the way before the NYC average permanently drops under 20” in the coming years and decades.

The only temperatures which matter for the snow fans are on the day which the precipitation is falling. Doesn’t matter what the average winter temperature was. So unless we can get colder storm tracks in the coming years, we will continue to see this much lower snowfall pattern which began around 18-19. Hopefully, we can shift the persistent warm storm track to something more favorable for heavier snows in the coming years. The biggest issue has been that the storm tracks have been too warm for much snow. While NYC generally has needed winter average temperatures near 32.0° for bigger seasons approaching 50” or higher, they have reached 20-30” or more with warmer winters that had cold enough storm tracks. We saw this in 15-16, 16-17, 17-18, and 20-21. So while this winter had near average historical temperatures, the storm tracks were too warm. This lead to the average temperature for the days on which .25 or more of precipitation fell to be 41.5°. This was significantly warmer than the winter average temperature of 34.8°. So this only gave NYC 12.9” of snow. The temperature in 86-87 also averaged 34.8°. But the average temperature on the days that .25 or more of precipitation fell was 37.0°. So the storm tracks were cold enough for 23.1” of snow on the season which was within a few inches of average.

The long range ensembles have been running too cool recently. Remember when the EPS only had 40s yesterday and we made it into the 60s? So expect the ensembles to catch up with what some of the warmer OPs have been showing. First 70+ readings of the season will be a good bet at least for the usual warm spots in NJ sometime from March 10th through 17th. But sea breezes could keep Long Island in the 60s.

Still looking like our first 70 between March 10th and 17th. The good news for spring fans is that this will be another Southeast Ridge link up with the -AO. This is what happened a few weeks ago and parts of Long Island got close to 60° when the AO dropped to -5. So the -AO hasn’t been a cold signal like it was in the past. 2025-02-16 57 39 15Feb2025 -5.2570

The 42° drop at Newark over 18 hrs was the 3 greatest on record for March. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=EWR&v=tmpf&hours=18&month=mar&dir=cool&how=exact&_r=t&dpi=100&_fmt=png

Welcome to early spring in the Northeast.

The biggest issue has been that the storm tracks have been too warm for much snow. While NYC generally has needed winter average temperatures near 32.0° for bigger seasons approaching 50” or higher, they have reached 20-30” or more with warmer winters that had cold enough storm tracks. We saw this in 15-16, 16-17, 17-18, and 20-21. So while this winter had near average historical temperatures, the storm tracks were too warm. This lead to the average temperature for the days on which .25 or more of precipitation fell to be 41.5°. This was significantly warmer than the winter average temperature of 34.8°. So this only gave NYC 12.9” of snow. The temperature in 86-87 also averaged 34.8°. But the average temperature on the days that .25 or more of precipitation fell was 37.0°. So the storm tracks were cold enough for 23.1” of snow on the season which was within a few inches of average.

This could be our first decade without a NYC winter near 32°. Coldest NYC winters of each decade 2020s…..34.8° so far 2010s……31.4° 2000s…..31.2° 1990s……31.1° 1980s…...32.6° 1970s…….28.4° 1960s……29.9° 1950s…...30.8° 1940s…..30.0° 1930s…..28.3° 1920s…..29.9° 1910s……25.7° 1900s…..27.3° 1890s…..28.6° 1880s…..26.5° 1870s…..27.7°

This weekend will probably be the last chance for NYC to have a low in the low 20s and a high in the low 30s.

We could do 60° today with the warm downslope flow.

This will go down as our mildest -EPO+PNA -AO winter. We don’t often get a combination of blocking over Western North America extending from Alaska down to the Western US at the same time we get block near and to the west of Greenland. The past years like 2002-2003, 1985-1986, 1976-1977, and 1962-1963 were colder to much colder. Snowfall was near the bottom similar to 1985-1986. Notice how the ridges became more expansive leading to a smaller and weaker 500mb low near the Northeast.

One of the biggest changes we have seen in PA since the 1950s and 1960s has been the winter storm track shift. The primary winter storm track into the early 2000s was just east of the Appalachians. We can see how the storm track shift over the last 20 years caused a steep decline in snowfall at State College. The same storm track shift going west of the Appalachians has lead to in increase in Lake effect snows at Erie coupled with the warmer lake temperatures reducing the ice cover over the years.

February will finish very close to average temperatures with the late month warm up. The 7 station average is currently -0.1. And the winter finishes at -0.8°. But would be closer to 0.0° using the 1981-2010 climate normals which were about 1° cooler. Feb 2025 EWR….+0.4 NYC…..-1.6 LGA…..-0.9 JFK….+2.3 HPN….-0.6 BDR…-0.5 ISP.…+0.8 AVG…-0.1 Jan 2025 EWR…-1.4° NYC…-2.5° LGA….-2.0° JFK…..-0.2° HPN….-1.6° BDR….-1.3° ISP…...-1.5° AVG…..-1.5° Dec 2024 EWR….-0.1° NYC….-0.9° LGA…..-1.0° JFK…..+0.1° HPN….-1.6° BDR…..-1.3° ISP…….-0.6° AVG….-0.8° DJF AVG…..-0.8°

We haven’t had an average midrange 19” to 30” or above normal snowfall season since the 1990s without at least one big benchmark or KU snowstorm. So pretty much a 100% chance of below to much below snowfall with only the cutter, hugger, and suppressed Southern Stream storm tracks. But while the near BM tracks are necessary, they aren’t always sufficient to reach average to above as western sections found out in 2022. From the 1960s to early 1990s we could get to 19” or above some seasons without benchmark tracks or KUs. Since it was cold enough back then with enough of the other type of tracks we got which included clippers which we hardly ever see these days. Also SWFEs that had better cold air and high pressure for heavier snows. I think our last big overperforming SWFE type low was the 6”+ event in November 2018.

Another season dominated by the cutter, hugger, and suppressed Southern Stream storm tracks. Since 18-19 we only had a brief relaxation of this pattern during 20-21 and Jan 22. The much faster Northern Stream of the Pacific Jet seems to be interfering with a benchmark snowstorm track pattern. This has lead to the very low snowfall totals over this period. The Western Trough in one set of outcomes overamplifies with too much wave spacing pumping the Southeast Ridge leading to the Great Lakes Cutter track. The next group has slightly less wave spacing leading to a track which hugs the I-78, I-80, or I-95 corridor leading to snow to rain outcomes favoring closer to I-84 and north for best snows. Then the third grouping has a kicker coming onto the West causing the Southern Stream system to get suppressed to our south with just light snows or no snow at all. Not sure what it could take in coming seasons to change up this pattern. Maybe a shift in the many ongoing marine heatwaves. But very uncertain since this jet and storm track pattern emerged with the rapid expansion of these marine heatwaves around 2019. Seasonal animation below illustrates this snowfall and storm track pattern

Yeah, we can add this new study also.

Yeah, LGA already set the new record for under 4” days this season currently at 1123 and NYC is getting close to their record. Number of Consecutive Days Snowfall < 4 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Period of record: 1940-01-01 to 2025-02-25 1 1123 2025-02-25 2 1051 1963-12-22 3 761 2020-12-15 4 746 1952-02-29 5 744 1981-03-04 6 743 1998-03-21 7 742 2013-02-07 8 715 1974-02-07 9 701 1977-01-13 10 690 1943-01-27 Number of Consecutive Days Snowfall < 4 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Last value also occurred in one or more previous years. Period of record: 1869-01-01 to 2025-02-25 1 1394 1932-12-16 2 1123 2025-02-25 3 1063 1952-01-27 4 1051 1963-12-22 5 794 1956-03-15 6 743 1998-03-21 7 742 1920-02-03 8 687 1981-01-06 9 685 1974-01-08 10 680 1954-01-10

March and April snowfall has been way down during the 2020s. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 0.1 T 0.1 2024 T 0.0 T 2023 0.1 0.0 0.1 2022 0.4 0.0 0.4 2021 T 0.0 T 2020 T T T Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 6.0 0.6 6.5 2019 10.4 0.0 10.4 2018 11.6 5.5 17.1 2017 9.7 0.0 9.7 2016 0.9 T 0.9 2015 18.6 0.0 18.6 2014 0.1 T 0.1 2013 7.3 0.0 7.3 2012 0.0 0.0 0.0 2011 1.0 T 1.0 2010 T 0.0 T Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 3.5 0.5 4.0 2009 8.3 T 8.3 2008 T 0.0 T 2007 6.0 T 6.0 2006 1.3 0.1 1.4 2005 6.9 0.0 6.9 2004 4.8 0.0 4.8 2003 3.5 4.0 7.5 2002 T T T 2001 3.8 0.0 3.8 2000 0.4 1.2 1.6 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 5.7 0.1 5.8 1999 4.5 0.0 4.5 1998 5.0 0.0 5.0 1997 1.7 T 1.7 1996 13.2 0.7 13.9 1995 T T T 1994 8.1 0.0 8.1 1993 11.9 0.0 11.9 1992 9.4 T 9.4 1991 0.2 0.0 0.2 1990 3.1 0.6 3.7 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 3.0 1.0 4.1 1989 2.5 0.0 2.5 1988 T 0.0 T 1987 1.9 0.0 1.9 1986 T T T 1985 0.2 T 0.2 1984 11.9 0.0 11.9 1983 T 0.8 0.8 1982 0.7 9.6 10.3 1981 8.6 0.0 8.6 1980 4.6 T 4.6 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 2.3 0.1 2.4 1979 T T T 1978 6.8 T 6.8 1977 0.6 T 0.6 1976 4.4 T 4.4 1975 0.3 T 0.3 1974 3.2 0.3 3.5 1973 0.2 T 0.2 1972 2.3 T 2.3 1971 1.3 0.4 1.7 1970 4.0 T 4.0 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 6.1 0.1 6.2 1969 5.6 0.0 5.6 1968 6.1 0.0 6.1 1967 17.4 T 17.4 1966 T 0.0 T 1965 2.8 1.2 4.0 1964 6.0 T 6.0 1963 2.8 T 2.8 1962 0.2 T 0.2 1961 1.2 T 1.2 1960 18.5 0.0 18.5 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 6.2 1.0 7.2 1959 6.7 0.6 7.3 1958 15.9 0.2 16.1 1957 2.6 2.5 5.1 1956 21.1 4.2 25.3 1955 3.6 0.0 3.6 1954 0.1 0.3 0.4 1953 0.9 T 0.9 1952 7.4 0.0 7.4 1951 2.7 0.0 2.7 1950 1.4 1.9 3.3

It will take Islip longer than NYC. Number of Consecutive Days Snowfall < 5 for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. 1 1503 1969-12-28 through 1974-02-07 2 1205 1989-11-24 through 1993-03-12 3 1123 2022-01-30 through 2025-02-25 4 1061 1984-03-29 through 1987-02-22 5 1000 2018-03-22 through 2020-12-15 6 758 1997-02-15 through 1999-03-14 7 744 1979-02-20 through 1981-03-04 8 742 2011-01-28 through 2013-02-07 9 689 1967-03-23 through 1969-02-08 10 655 1999-03-16 through 2000-12-29 Number of Consecutive Days Snowfall < 5 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Period of record: 1869-01-01 to 2025-02-25 1 1394 1929-02-22 through 1932-12-16 2 1123 2022-01-30 through 2025-02-25 3 1063 1949-03-01 through 1952-01-27 4 1051 1961-02-05 through 1963-12-22 5 794 1954-01-12 through 1956-03-15 6 764 1996-02-17 through 1998-03-21 7 761 2018-11-16 through 2020-12-15 8 744 1979-02-20 through 1981-03-04 9 742 2011-01-28 through 2013-02-07 - 742 1918-01-23 through 1920-02-03

That big -5 AO drop was the main reason this didn’t turn into another +5 February with how strong the Southeast Ridge was.

If the data suggested that it was getting much colder over that period, then my guess is that you would have no problem believing it. Plus when you use terms like “no one can tell” it shows that you didn’t read the study. The issue is that you are viewing scientific information through a political filter which is warping your perception of reality.

It’s the speed of the warming which is unprecedented in the last 24,000 years. https://news.arizona.edu/news/global-temperatures-over-last-24000-years-show-todays-warming-unprecedented A University of Arizona-led effort to reconstruct Earth's climate since the last ice age, about 24,000 years ago, highlights the main drivers of climate change and how far out of bounds human activity has pushed the climate system. The study, published Wednesday in Nature, has three main findings: It verifies that the main drivers of climate change since the last ice age are rising greenhouse gas concentrations and the retreat of the ice sheets. It suggests a general warming trend over the last 10,000 years, settling a decade-long debate the paleoclimatology community about whether this period trended warmer or cooler. The magnitude and rate warming over the last 150 years far surpasses the magnitude and rate of changes over the last 24,000 years. "This reconstruction suggests that current temperatures are unprecedented in 24,000 years, and also suggests that the speed of human-caused global warming is faster than anything we've seen in that same time," said Jessica Tierney, a UArizona geosciencesassociate professor and co-author of the study.