bluewave

The last 7 snowfall seasons have been the lowest 7 year snowfall combined from Philly up to Boston. It has been a result of the much warmer winters and the warmer storm tracks. Since the 1990s, this region has relied heavily on coastal Noreaster tracks near the 40/70 benchmark to reach average to above average snowfall. In the colder era before the 1990s, there were several seasons reaching average snowfall without big KU NESIS snowstorms. So there were more ways to break even in a colder climate. Since tracks further to the west didn’t draw in the amount of warmth we have experienced with the cutter and hugger tracks over the last 7 seasons. Places like NYC have come to rely exclusively on this benchmark storm track just to approach average last 30 years. So when just one type of storm track which can be a smaller percentage of the total storm tracks essentially shuts off, the outcome has been record low snowfall averages over 7 years. While the region experienced their first average temperature winter in a decade this winter, the storm tracks were still too warm for heavy snows in places like NYC. Since the storm day winter average temperature was 41.0°. So this muted the effect of the 34.8° winter average temperature which was very close to the 1951 to 2010 long term average. This has been the first 7 year period with such low snowfall being the result of warmth. Past 7 year snow droughts were usually the result of drier patterns and not lack of cold for winter average temperatures and storm tracks. In the colder climate we occasionally had dry stretches. So shifting back closer to average snowfall for the remainder of the 2020s will be more of a challenge now since the warmth has continued increasing. Those past record low 7 year stretches all ended with heavy snowfall with NYC seeing upwards of 50” and 60” to over 70”. Such higher totals for especially from Philly to NYC will be a challenge in the much warmer 2020s climate. Boston probably has more leeway to break the snow drought if we see a true benchmark storm track return since they are a colder climate than Philly and NYC. This highlights the challenges of having to rely so much on just one type of storm track for average to above average snowfall. This wasn’t the case in a colder climate for average snowfall seasons around NYC. But getting the big seasons still required the benchmark track. State College is a location that relied heavily on one type of storm track for their heavier snows. The a storm track called Apps or inside runner used to be very common there. These days we see more storms tracking west of the mountains and giving the Great Lakes historic snows. So State College has seen a steady 20 decline in their snowfall over the last 20 years. I am hoping this isn’t a good comparison to benchmark tracks since we are only 7 years in and not 20 years like State College. So it will be interesting to see what happens during the rest of the 2020s. 7 year running average record low snowfall PHI….2025….13.6”…….1992…..14.9”……95-96….65.5”….1955….13.4”……57-58….41.8” NYC…2025….14.9”…...1992…..16.3”…..93-94…53.4”….95-96….73.6”…1976….17.2”…77-78….50.7”…..1956….17.0”….57-58….44.7”…..1932….15.4”….33-34…..52.0” BOS….2025…..26.6”…….1992…..29.9”…..92-93….83.9”….93-94….90.3”….95-96….107.6”……1955….29.9”…..55-56…..60.9”…..56-57….52”

Yeah, this has been a slightly lower 7 year running mean for snowfall than we had in the 70s and 80s.Those were a result of dry patterns and not warm ones like we have been getting since 18-19. So it’s less likely that we see multiple 50”+ seasons next few years to break this drought like those ones did in 77-78, and 93-94, and 95-96. Becoming too warm for heavier snows is a bigger hurdle than overcoming the occasional dry spell in a colder climate. This year was too warm on the days with .25 of precipitation with an average of 41.0°. So the storm tracks made it too warm for much snow this past winter. Other recent winters had both warm storm tracks and average winter temperatures. So the winter average of 34.8° didn’t do us much good since it was mostly on the days without precipitation. JFK and other local stations new record lowest 7 year snow average of 14.5”.

The EPO will be positive with a -PNA so the -AO will just trap seasonal Pacific air underneath. The good news is that we can get some much needed rainfall with the very fast Pacific flow continuing into late March. Hopefully, the dry pattern since last fall will gradually abate by the time we get to the summer.

The EPS only had 40s last Saturday and me made it to the mid-60s. So it has been running a cold bias all winter. These are the 90 day averages so individual days like last Saturday can have much greater bias.

100% of all seasons since the 1990s with average to above average snowfall had benchmark snowstorm tracks. I am using a 19” to 31” range as average for EWR to ISP. If it’s say only 15% of the total storm tracks if it’s that 15% which is 100% critical to our seasonal snowfall reaching average. So remove the 15% and you are 100% guaranteeing a below average snowfall season. So having to just rely on one narrower type of storm track for average to above average snowfall leaves us open to lower totals when that track doesn’t materialize. I not sure of the exact percentage but just using the 15% figure being discussed. In the colder climate from the 60s to early 90s, we could rely on tracks to the west of the benchmark including huggers ,clippers, and inside runners to get to average snowfall in the 19” to 26” range. It was even cold enough at times to get decent front end thumps with cutters since it would take longer to scour out the cold air. But the bigger seasons over 30” had benchmark tracks added to the mix. Now we struggle to get much past 15” in recent years around NYC with cutters, and huggers which are significantly warmer than they used to be. Plus we also lost the clipper snowstorm tracks. This is why we are going to need the benchmark tracks return in coming years for our area to reach average or above average snowfall. And avoid a permanent shift well below 20” as our new norm. The next several years will be telling if we are to avoid extending these 7 year record snowfall lows into 10 years or more.

The good news is that it will be mild Pacific air trapped under the block. So we’ll drop back closer to seasonable temperatures for a time. But not the highs in the low 30s and lows near 20° like we just got.

I agree with what you are saying to some extent with the magnitude of the +PNA coming in significantly higher than we have seen in past cases. This goes to the greater shift we have seen since May 2023 with the record blocking and warmth which has dominated in Canada. It’s quite possible that we are at the beginning of some new type of Pacific shift which we don’t fully understand yet. As global temperatures have greatly exceed past cases of Nino into La Niña transitions. Notice how much warmer Nino 1+2 remained this winter even though we were in La Niña.

I use the 500 mb charts for the teleconnections. We can see the +PNA was from December into January like the past analogs that I mentioned. The 500 mb PNA was solidly negative in February with the deep trough near the Pacific Northwest and Southeast Ridge. Chuck pointed this out earlier the thread. But the much faster Pacific Jet rendered all those teleconnections moot in regard to the snowfall especially closer to my area. So NYC got a mild Pacific zonal flow pattern with a winter average temperature of 41.5° on the days that .25 or more of precipitation fell. We were effectively too warm on the storm days for much snowfall with only 12.9” on the season. It lead to the paradox of the Euro seasonal having a correct snowfall forecast around my area even though it had a warmer forecast than the 34.8° average. So a continuation of the warmer storm tracks and lower snowfall which has dominated since 18-19.

Yeah, we effectively got a mild Pacific zonal flow this winter on the days that .25 of precipitation fell in NYC. Those days averaged 41.5°. Same story since 18-19 with cutters, huggers, and suppressed Southern Stream storm tracks dominating.

Good to see the GFS joining the Euro on 70° potential next week for the warm spots as everyone is ready for spring at this point.

The end result was a very strong La Niña Pacific Jet do to the background Maritime Continent forcing and record WPAC SST warmth. This is why we had such low snowfall despite what used to be favorable teleconnectiins in the past like a-5 daily AO, +PNA, and -EPO. Constant parade of storms cutting through the Great Lakes or hugging the I-95, I80, I-78 corridors. So we effectively got a mild zonal flow on the days which we had the storms negating the colder than recent winter tempersrures.

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.