bluewave

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.

Yes. https://www.wpc.ncep.noaa.gov/metwatch/metwatch_mpd_multi.php?md=1220&yr=2025 However, OSPO's ALPW has since shown an increase stemming from Melissa's circulation, especially near and below 700 mb, being drawn northward into NJ and southern NY. The continued addition of this remnant tropical moisture should allow for an increase in rainfall efficiency and locally higher rainfall rate potential into the early evening hours.

Even before that 2nd coldest late December 2017 into early January 2018 period, most areas from Philly to NYC Metro still made it above 55° from the 17th to 25th like every year since 2011. Many of those years the long range models missed that warm up. But once we got past the first week of December, the models played catch up the closer in time we get to the period. Data for December 17, 2017 through December 25, 2017 Click column heading to sort ascending, click again to sort descending. Atlantic City Area ThreadEx 61 CAPE MAY 2 NW COOP 61 MILLVILLE MUNICIPAL AIRPORT WBAN 61 ATLANTIC CITY INTL AP WBAN 61 INDIAN MILLS 2 W COOP 61 ESTELL MANOR COOP 61 SOUTH JERSEY REGIONAL AIRPORT WBAN 61 HAMMONTON 1 NE COOP 60 ATSION COOP 60 EB FORSYTHE NEW JERSEY RAWS 60 PHILADELPHIA/MT. HOLLY WFO COOP 59 MANASQUAN 1 NW COOP 59 WRIGHTSTOWN COOP 59 PENNSAUKEN 1N COOP 59 Trenton Area ThreadEx 58 New Brunswick Area ThreadEx 58 SEABROOK FARMS COOP 58 HIGHTSTOWN 2 W COOP 58 TRENTON-MERCER AIRPORT WBAN 58 NEW BRUNSWICK 3 SE COOP 58 Newark Area ThreadEx 57 FREEHOLD-MARLBORO COOP 57 NEWARK LIBERTY INTL AP WBAN 57 SOMERSET AIRPORT WBAN 57 TETERBORO AIRPORT COOP 56 MARGATE COOP 56 Atlantic City Marina Area ThreadEx 56 ATLANTIC CITY MARINA WBAN 56 WERTSVILLE 4 NE COOP 56 TETERBORO AIRPORT WBAN 56 HARRISON COOP 56 FLEMINGTON 5 NNW COOP 55 PHILLIPSBURG-EASTON BRIDGE COOP 55 CANOE BROOK COOP 55 Data for December 17, 2017 through December 25, 2017 Click column heading to sort ascending, click again to sort descending. MONTAUK AIRPORT WBAN 57 LAGUARDIA AIRPORT WBAN 56 WESTHAMPTON GABRESKI AP WBAN 56 MOUNT SINAI COOP 56 SHIRLEY BROOKHAVEN AIRPORT WBAN 56 New York-LGA Area ThreadEx 56 BRIDGEHAMPTON COOP 55 FARMINGDALE REPUBLIC AP WBAN 55 ISLIP-LI MACARTHUR AP WBAN 55 NY CITY CENTRAL PARK WBAN 55 RIVERHEAD RESEARCH FARM COOP 55 UPTON COOP - NWSFO NEW YORK COOP 55 JFK INTERNATIONAL AIRPORT WBAN 55 Islip Area ThreadEx 55 New York-Kennedy Airport Area ThreadEx 55 New York-Central Park Area ThreadEx 55

Just remember the long range models this time of year through November often show nice looking patterns to start December and try to continue them for the entire month. We saw this last year with the strong -EPO forecast from late November into December which reversed in mid to late December. The models completely underestimated the Pacific Jet and flip to +EPO later in December. The EPS weeklies in early December looked great for the whole month. But they kept underestimating the strength of the Pacific Jet. I was discussing this in the threads last December. This could be the case this year if the MJO slows in phase 6-7 later in November into early December and loops back into the circle before emerging into 4-6 by mid or late December. Just something to watch since we have had warm ups every December since 2011 from 16th to the 25th like clockwork. These periods had convection near the MJO 4-6 phases which weren’t very well forecast in advance. Plus even if the MJO wasn’t too amplified in phases 4-6, it would still shift the pattern warmer than the start of the month. There could be a new seasonality to this since the 2nd half of December has been warming at faster rate than early December. I have been discussing this since 2011. Anthony Masiello also made a post about this for his area last December on one of the social media platforms.

Yeah, we had accumulating snows around the area with the colder storm tracks and background temperatures at the end of October 2008 and 2011. Then the big post Sandy snowstorm in November 2012 and SWFE in November 2018. The best obviously for the whole season was the late November 1995 snow which carried through until early April 1996. Before that the lack of snow following the November 1989 Thanksgiving snowstorm. Plus the earliest October 10, 1979 snows before the low seasonal snows that winter with the big suppression pattern when Virginia did so well.

Our last successful MJO 8 with a cold and snowy benchmark pattern was back in January 2022. This featured the relaxation of the Pacific Jet. As recently as last February the MJO stalled out in Phase 7 before going back into the circle. So the Pacific Jet remained extended near record levels and we got our first -5 SD Greenland block linking up with the Southeast ridge with a big cutter and Toronto record snowstorm. Last February was a west based La Niña with a warm Nino 1+2. During January 2022 we got a stronger east based La Niña when the forcing made into the favorable phase 8. So with how strong the Pacific Jet currently is and it’s only October, would want to see a phase 8 at some point this winter in order to potentially weaken it with such a strong gradient between Siberia and the WPAC to south of the Aleutians. But won’t have any confidence in such an outcome until we get to within the short term. Since the default since February 2022 has been the MJO getting over to 6-7 and heading back into the circle and missing phase 8. Even when the RMM charts went into 8 during March 2023, the Pacific Jet wasn’t able to relax so the storm hugged the coast and the NE higher elevations cashed in instead. March 2023 was also a west based La Niña with warming in Nino 1+2. So even if we can see a phase 8 this winter, it’s no guarantee we will see what happed in January 2022 again as Nino 1+2 has remained warmer than 3.4 into this fall. As the EWBs have been stalling out further west.