bluewave

From 2019 to 2025 with the lack of benchmark storm tracks ISP has only averaged 1.9” more than NYC with record 7 year lows for both sites at 16.8” and 14.9”. Since neither site does well with Great Lakes cutters, I-78 huggers, and suppressed Southern Stream storm tracks. During 2010 to 2019 ISP averaged 8.5” more than NYC since it was closer to all the benchmark storm tracks. It was the only 9 year period that ISP averaged near 50” a season. It was the golden age for benchmark KU storm tracks. From 1994 to 2009 ISP and NYC were also more evenly balanced around 28.0” a year since it was colder and we still had a good amount of benchmark storm tracks in the mix. During the colder era from 1964 to 1993, ISP averaged 25.8” a year vs 23.0” in NYC. So both ISP and NYC could average over 20” a year without having to exclusively rely on benchmark KU tracks. It was cold enough for hugger tracks to drop more on the front end before mixing or changeover. Plus we got more clippers dropping south of the area which have been lacking since then. Since 1993-1994 both ISP and NYC haven’t had over 20” without at least one benchmark KU snowstorm. Prior to 1993-1994 in the much colder climate we could get closer to average without a KU. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean T 0.6 2.1 6.0 7.1 1.0 T 16.8 2024-2025 0.0 0.0 2.1 2.7 6.9 0.0 0.0 11.7 2023-2024 0.0 T T 3.1 7.8 0.0 0.0 10.9 2022-2023 0.0 0.0 0.4 T 3.0 1.6 0.0 5.0 2021-2022 0.0 T 0.3 31.8 3.3 1.6 0.0 37.0 2020-2021 T 0.0 7.5 1.1 24.9 T T 33.5 2019-2020 0.0 0.1 4.2 2.5 0.0 T T 6.8 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 12.8 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 0.0 0.9 2.3 3.7 6.4 1.6 T 14.9 2024-2025 0.0 0.0 2.8 3.0 7.1 0.0 0.0 12.9 2023-2024 0.0 T T 2.3 5.2 T 0.0 7.5 2022-2023 0.0 0.0 T T 2.2 0.1 0.0 2.3 2021-2022 0.0 T 0.2 15.3 2.0 0.4 0.0 17.9 2020-2021 0.0 0.0 10.5 2.1 26.0 T 0.0 38.6 2019-2020 0.0 0.0 2.5 2.3 T T T 4.8 2018-2019 0.0 6.4 T 1.1 2.6 10.4 0.0 20.5 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean 0.0 0.5 6.5 18.2 13.9 8.6 0.6 48.3 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 65.9 2016-2017 T T 3.2 14.0 14.7 7.4 T 39.3 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 41.4 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 63.7 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 63.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 46.9 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 4.7 2010-2011 0.0 T 14.9 34.4 3.9 2.1 T 55.3 2009-2010 0.0 0.0 25.3 6.4 21.7 0.4 0.0 53.8 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 0.3 0.5 5.9 14.2 12.8 5.5 0.6 39.8 2017-2018 0.0 T 7.7 11.2 4.9 11.6 5.5 40.9 2016-2017 0.0 T 3.2 7.9 9.4 9.7 0.0 30.2 2015-2016 0.0 0.0 T 27.9 4.0 0.9 T 32.8 2014-2015 0.0 0.2 1.0 16.9 13.6 18.6 0.0 50.3 2013-2014 0.0 T 8.6 19.7 29.0 0.1 T 57.4 2012-2013 0.0 4.7 0.4 1.5 12.2 7.3 0.0 26.1 2011-2012 2.9 0.0 0.0 4.3 0.2 0.0 0.0 7.4 2010-2011 0.0 T 20.1 36.0 4.8 1.0 T 61.9 2009-2010 0.0 0.0 12.4 2.1 36.9 T 0.0 51.4 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Mean T 0.3 5.8 7.1 8.7 5.3 1.0 28.3 2008-2009 0.0 T 10.4 8.9 3.3 13.6 T 36.2 2007-2008 0.0 0.0 2.6 0.8 7.3 T 0.0 10.7 2006-2007 0.0 T 0.0 1.0 4.2 3.8 T 9.0 2005-2006 0.0 0.5 7.6 4.7 19.9 3.2 0.1 36.0 2004-2005 0.0 T 7.0 21.5 17.0 13.3 0.0 58.8 2003-2004 0.0 0.0 15.5 19.1 1.1 5.7 0.0 41.4 2002-2003 0.0 1.0 16.0 2.6 26.3 3.7 5.0 54.6 2001-2002 0.0 0.0 0.0 3.7 T T 0.0 3.7 2000-2001 T 0.0 10.8 9.2 8.6 10.3 T 38.9 1999-2000 0.0 T 0.4 5.8 2.6 0.2 T 9.0 1998-1999 0.0 0.0 3.0 4.5 2.8 9.1 T 19.4 1997-1998 0.0 T 1.0 T T 1.6 T 2.6 1996-1997 0.0 T 1.2 3.3 2.2 3.7 2.0 12.4 1995-1996 0.0 3.0 13.3 20.2 19.0 12.0 9.6 77.1 1994-1995 0.0 T T T 5.1 T 0.0 5.1 1993-1994 0.0 T 3.3 8.8 20.0 5.0 0.0 37.1 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean T 0.2 5.4 7.5 10.4 4.2 0.4 28.0 2008-2009 0.0 T 6.0 9.0 4.3 8.3 T 27.6 2007-2008 0.0 T 2.9 T 9.0 T 0.0 11.9 2006-2007 0.0 0.0 0.0 2.6 3.8 6.0 T 12.4 2005-2006 0.0 T 9.7 2.0 26.9 1.3 0.1 40.0 2004-2005 0.0 T 3.0 15.3 15.8 6.9 0.0 41.0 2003-2004 0.0 0.0 19.8 17.3 0.7 4.8 0.0 42.6 2002-2003 T T 11.0 4.7 26.1 3.5 4.0 49.3 2001-2002 0.0 0.0 T 3.5 T T T 3.5 2000-2001 T 0.0 13.4 8.3 9.5 3.8 0.0 35.0 1999-2000 0.0 0.0 T 9.5 5.2 0.4 1.2 16.3 1998-1999 0.0 0.0 2.0 4.5 1.7 4.5 0.0 12.7 1997-1998 0.0 T T 0.5 0.0 5.0 0.0 5.5 1996-1997 0.0 0.1 T 4.4 3.8 1.7 T 10.0 1995-1996 0.0 2.9 11.5 26.1 21.2 13.2 0.7 75.6 1994-1995 0.0 T T 0.2 11.6 T T 11.8 1993-1994 0.0 T 6.9 12.0 26.4 8.1 0.0 53.4

It’s been a challenge maintaining strong enough 500mb blocking across the WPO, EPO, PNA, and TNH regions. The last time we pulled this feat off was January 2022. Last winter the block kept getting undercut and eroded from the very fast Pacific Jet sending shortwaves through. So this continued the Great Lakes cutter, I-78 to I-84 hugger, and suppressed Southern Stream storm tracks.

I am going weaker on the PNA than last winter. But there could still be +PNA intervals. Very strong warmth and 500mb ridging in Canada since May 2023.

It’s based in the peak MJO 5 phase in October. Since the MJO weakened into phase 5 after moving through phase 4. But even if that 2.42 made it into 5, then it would still be lower than the 2.76 to 3.35 of the mismatch years.

Weaker MJO 5 peak this October similar to the non PNA mismatch years like 2022, 2021, and 2016. I was expecting this since we haven’t had two back to back La Niña PNA mismatch winters before. So a milder signal for temperatures than last winter. Could still be some +PNA intervals just weaker than we had last winter. http://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt October 2025….Phase 5 peak +1.302… October 2024….Phase 5 peak +2.762…ONI….latest weekly only -0.3 October 2022…Phase 6 peak +2.177…..ONI….-1.0 October 2021….Phase 5 peak +2.087….ONI….-1.0 October 2020…Phase 5 peak +2.818….ONI…..-1.3 October 2017….Phase 6 peak +3.353….ONI….-1.0 October 2016….Phase 5 peak +1.800….ONI….-0.7

Another similarity to the fall of 2021 and 2022 like we are also seeing with the strong +WPO in October. https://ozonewatch.gsfc.nasa.gov/meteorology/wind_2021_MERRA2_NH.html

That big +WPO vortex is similar to October 2021 and 2022. It creates a steep gradient between the cold in Siberia and the record WPAC warm pool. So we get a very fast Pacific Jet as a result with frequent lows cutting through the Great Lakes. Climatologist49 ‪@climatologist49.bsky.social‬ Follow A nice 200+ mph (333+ kmh) tail wind as we head over the central north Pacific Ocean this morning. October 23, 2025 at 5:37 AM

Very fast Northern Stream pattern continues into November. A storm system cutting through or north of the Great Lakes every few days. Tough to get much in the way of coastal storm development as we have seen in recent years. So we get warm-ups ahead of the lows and cool-downs behind. But no significant cold for this time of year due to such a strong Pacific influence. North America is very warm for this time of year and all the real cold is over in Siberia. This contrast between the record SSTs in the North Pacific drives the fast Pacific Jet. November 3 to 10 EPS forecast

I just recently ordered the WH31P thermometer and will use it as a stand-alone unit. Since I don’t have an open area for the anemometer. Plus their console is a little busy for me and doesn’t have the cleaner look of the Davis. I tested the WH31E sensor and it lines up very well with the other local Wunderground sites near me and tweed airport very well.

The higher resolution ensemble charts are showing the same scenario. Very fast Pacific flow with warm ups followed by brief cooldowns. Storm track from east to west the through the Great Lakes and exiting to the east of New England. Very little room for an amped coastal track close to the coast like the OP GFS has with that much snow. Any trailing energy lagging behind the main low looks pretty weak and sheared out to our east. But it’s possible the upper low behind the main low could cause some moisture to linger for flurries especially higher elevations in our area. We can always get some flurries even near the coast this time of year especially early in the day if the timing is right.

The Northern Stream is very dominant on both EPS and GEFS. So it’s unlikely we see a coastal storm cold enough for the kind of snows the GFS near our area in early November with a primary storm track to our north. This was the case with some of the long range OP model runs trying to bring the hurricane up the coast. Instead the primary low cut to our west and the hurricane was kicked out to the southeast. So any trailing energy will probably shear out to our SE. But there could always be a couple of flurries if there is some lingering moisture behind the front. Just not in the way the OP GFS has.

That OP run is a big outlier among its ensembles.

The December level for snowfall at NYC, EWR, and LGA is 4”. There have been 15 La Niña winters between 95-96 and 24-25. The December 4” snowfall indicator has correctly worked 14 out of 15 times. The under 4” December snowfall last winter was a good early indicator for the rest of the season at the 3 stations for a below average finish. This must be due to La Ninas being frontloaded in nature and December showing the seasonal pattern early. The only time it didn’t work was the 16-17 La Niña. For Decembers with under 4” at those stations the seasonal totals went on to finish below average. For the Decembers with more than 4” during La Ninas the seasons finished above average snowfall. So a 93% success rate between 95-96 and 24-25. OCT to APR Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 2024-2025 0.0 0.0 2.8 3.0 7.1 0.0 0.0 12.9 2022-2023 0.0 0.0 T T 2.2 0.1 0.0 2.3 2021-2022 0.0 T 0.2 15.3 2.0 0.4 0.0 17.9 2020-2021 0.0 0.0 10.5 2.1 26.0 T 0.0 38.6 2017-2018 0.0 T 7.7 11.2 4.9 11.6 5.5 40.9 2016-2017 0.0 T 3.2 7.9 9.4 9.7 0.0 30.2 2011-2012 2.9 0.0 0.0 4.3 0.2 0.0 0.0 7.4 2010-2011 0.0 T 20.1 36.0 4.8 1.0 T 61.9 2008-2009 0.0 T 6.0 9.0 4.3 8.3 T 27.6 2007-2008 0.0 T 2.9 T 9.0 T 0.0 11.9 2005-2006 0.0 T 9.7 2.0 26.9 1.3 0.1 40.0 2000-2001 T 0.0 13.4 8.3 9.5 3.8 0.0 35.0 1999-2000 0.0 0.0 T 9.5 5.2 0.4 1.2 16.3 1998-1999 0.0 0.0 2.0 4.5 1.7 4.5 0.0 12.7 1995-1996 0.0 2.9 11.5 26.1 21.2 13.2 0.7 75.6

Unfortunately, it was just strong enough in the 5-7 phases last February to really pump the Southeast ridge and force the best snows up closer to Toronto. We got the classic weakening before 8 which has been common since February 2022. Even when we got the phase 8 in March 2023, it favored the higher elevations of the Northeast for the best snows.

Did you try a radiation shield? I know that Ambient sells separate radiation shields for their sensors. The more expensive stations like Davis have a fan aspirated shield. https://ambientweather.com/wh31-srs-solar-radiation-shield?srsltid=AfmBOorz7EtGt-FN_WSBnQcQN8KyI1q2M0m0rrY8pdsVqiMRaXYAlYm6 https://ambientweather.com/amwesrpatean.html?srsltid=AfmBOopKyQ4VW7xznO4qgQROflDAcsKdO1GId74O8ZUjp8Tr-Oz9zXpN

1993-1994 to 2014-2015 was the golden age for snowfall at many locations with new all-time seasonal highs being set. A sweet spot between the colder and drier winter regime prior to this era. We had just enough warming to add moisture for all the record snows but not too much like over the last decade leading to the reduction in snowfall. Time Series Summary for Detroit Area, MI (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2014-05-31 94.9 0 2 1881-05-31 79.4 31 3 1926-05-31 78.0 0 4 1982-05-31 74.0 0 5 2008-05-31 71.7 0 Time Series Summary for STATE COLLEGE, PA Click column heading to sort ascending, click again to sort descending. 1 1994-05-31 109.3 0 2 1996-05-31 99.0 0 3 1978-05-31 98.2 0 4 1993-05-31 92.5 0 5 1961-05-31 91.9 0 Time Series Summary for Washington Area, DC (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2010-05-31 56.1 0 2 1899-05-31 54.4 0 3 1905-05-31 46.8 0 4 1922-05-31 46.5 0 5 1996-05-31 46.0 0 - 1909-05-31 46.0 0 Time Series Summary for Baltimore Area, MD (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2010-05-31 77.0 0 2 1996-05-31 62.5 1 3 2003-05-31 58.1 0 4 1964-05-31 51.8 0 5 1899-05-31 51.1 0 Time Series Summary for Philadelphia Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2010-05-31 78.7 0 2 2014-05-31 68.0 0 3 1996-05-31 65.5 0 4 1899-05-31 55.4 0 5 1978-05-31 54.9 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 1 1996-05-31 75.6 0 2 1948-05-31 63.9 0 3 2011-05-31 61.9 0 4 1923-05-31 60.4 0 5 1873-05-31 60.2 0 Time Series Summary for Boston Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. 1 2015-05-31 110.6 0 2 1996-05-31 107.6 0 3 1994-05-31 96.3 0 4 1948-05-31 89.2 0 5 2005-05-31 86.6 0

My coldest of the season so far at 33°.

The 1979 to 1993 period was a snowfall bonanza along the I-95 corridor from DC to Boston compared to 2019 to 2025 .That’s due to the colder storm tracks and overall colder winter pattern back then. These days we have to contend with warmer storm tracks and warmer winters. 1979 to 1993 average snowfall DCA….16.7” PHL….20.5” NYC….20.1” BOS….34.6” Avg…..23.0” 2019 to 2025 average snowfall DCA…8.5” PHL…10.5” NYC…14.9” BOS….26.6” Avg….15.1”

I am happy for you guys that you got in such a great winter just before the big winter temperature jump since the 2015-2016 super El Niño.

It’s tough to determine that NYC would be cooler on calm clear nights if the sensors were in a clearing instead of under the trees. Since the park is in the middle of one of the strongest heat islands in the country like LGA. So that makes the tree effects on radiational cooling nights harder to determine. We do know that the winter low temperature is warming a little slower than LGA. Plus LGA is often a few degrees warmer for the lows. So the lows have been warming at a faster rate at LGA than NYC. LGA is right on the water which keeps it warmer during the winter also. If we look at the average minimum temperatures this past winter with the tree growth vs 1961 with less, LGA is still a little warmer than NYC. So not much of a difference. Even with the lack of trees Central Park wasn’t radiating much better relative to the surrounding stations. The average winter low was still within a degree of LGA. Data for December 1, 2024 through February 28, 2025 mean min temperature Click column heading to sort ascending, click again to sort descending. NY MONTAUK AIRPORT WBAN 32.6 NY LAGUARDIA AIRPORT WBAN 30.2 NY JFK INTERNATIONAL AIRPORT WBAN 30.0 NY NY CITY CENTRAL PARK WBAN 29.3 NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 29.3 NJ NEWARK LIBERTY INTL AP WBAN 28.0 NY RIVERHEAD RESEARCH FARM COOP 27.7 NY ORIENT POINT STATE PARK COOP 27.5 Data for December 1, 1961 through February 28, 1962 mean min temperature Click column heading to sort ascending, click again to sort descending. NY NEW YORK AVE V BROOKLYN COOP 27.6 NY NEW YORK LAUREL HILL COOP 27.4 NY LAGUARDIA AIRPORT WBAN 27.4 NY NEW YORK FLOYD BENNETT FIELD WBAN 27.2 NY NY CITY CENTRAL PARK WBAN 27.1 NY HEMPSTEAD MALVERNE COOP 26.3 NJ JERSEY CITY COOP 26.0 NY MINEOLA COOP 26.0 NY SETAUKET STRONG COOP 25.5 NY JFK INTERNATIONAL AIRPORT WBAN 25.3 NJ NEWARK LIBERTY INTL AP WBAN 25.1

Most spots will finish with another warmer than average month since the warm ups continue to be more impressive than the cooldowns.

None of those storm drains in Brooklyn where the worst flooding occurred were built to handle 1.00” of rain in only 15 minutes. While the spots that got over 2” yesterday wasn’t their heaviest daily rainfall event in recent years, 1 inch of rain in 15 minutes is probably close to the all-time records for the individual spots in an around Crown Heights. https://www.wunderground.com/dashboard/pws/KNYNEWYO1727/table/2025-10-30/2025-10-30/daily 2:54 PM 60.0 °F 59.6 °F 99 % SW 4.4 mph 11.3 mph 29.66 in 0.24 in 1.19 in 0 5w/m² 2:59 PM 60.3 °F 59.9 °F 99 % SW 3.6 mph 8.3 mph 29.65 in 1.44 in 1.41 in 0 9.6w/m² 3:04 PM 60.3 °F 60.0 °F 99 % SSW 5.3 mph 10.1 mph 29.66 in 3.78 in 1.84 in 0 11.8w/m² 3:09 PM 60.3 °F 59.9 °F 99 % SSE 3.7 mph 8.9 mph 29.65 in 4.44 in 2.16 in 0

If we average the rate of the 90° day increase at EWR and LGA starting 30 years before the NYC ASOS was installed under the tree canopy, NYC would have closer to 28-29 days reaching 90° instead of the recent average of near 17-18. NYC had a few days less than EWR from 1961-1990. But a few more days than LGA did. Our recent 16 year stretch since 2010 has had the highest number on 90° days. So it makes sense that EWR to LGA has had a steady increase in 90° days over this period. We can see how the NYC station near the castle was out in the open and not under a canopy of trees from photographs of the site in the decades prior to the 1990s. Now it’s in the deep shade during peak heating hours when the trees are fully leafed out. There could even be a smaller cooling effect during the winter due to the trees and lower sun angle creating a smaller shade effect.

The trend is correct since it incorporates the 30 years before and after the new ASOS was put into the shade in 1995. I have posted a whole series of charts and data showing the issues after the move in other threads in even greater detail. The MIC at Upon NWS office back in the early 2000s admitted as much in several news stories at the time. They had to make big compromises in the integrity of the Central Park record in order to keep the station open after the NWS moved out to Upton in 1993. Placing a thermometer under a tree canopy on sunny days when fully leafed out will result in at least a 2° to 3° cooling during the peak daily heating relative to the temperatures in a nearby clearing like the Great Lawn or other open areas of the park away from the dense wooded area next to the castle.