donsutherland1

January records for the New York City area:

With preliminary PNA values of -1.000 or below both yesterday and today, the snowstorm that just brought 4.3" to Central Park could become New York City's largest December snowfall with PNA values of -1.000 or below for all days during which the snow fell.

December 2025 will finish with a mean temperature below 35.0°C (coldest since 2010) and more than 6" of monthly snowfall. Below is how January fared in terms of snowfall following cold and snowy Decembers.

As forecasting accuracy requires, among other things, an objective assessment of the guidance, I've expanded the comparison of the 12/26 18z NAM and 12/26 18z HRRR. The major point of contention had been whether the NAM was providing a realistic forecast for the New York City area. It did not fare well. But what over a larger area? Again, the HRRR outperformed the NAM, but its forecasting edge was less decisive. The HRRR was better in assessing where the 4" or above snows would fall from New York City southward. The NAM confined such snows to the north and east of New York City. However, the HRRR was too aggressive in pushing 2"+ snows past Allentown and into Philadelphia. The HRRR also did better in such locations as Albany and Boston. 12/26 18z NAM: 12/26 18z HRRR: Outcomes for 12 Cities:

January 29, 2022.

The streak without a 4" or above snowstorm ended; the streak with less than 4" daily snowfall continues.

I believe it's a good measurement. Every site in Brooklyn, Queens, Manhattan, and the Bronx listed on the NWS PNS had 3" or more. JFK, LGA, and NYC all had somewhat over 4".

Five photos from this morning.

For snowstorms, it's over. Finally. For daily snowfalls, it, unfortunately, continues.

18z NAM vs. 18z HRRR: Here's how I fared against the two models: Final Accumulations: Bridgeport: 7.1" Islip: 6.6" New York City-Central Park: 4.3" New York City-JFK Airport: 4.1" New York City-LaGuardia Airport: 4.1" Newark: 4.2" The low end of the 4"-8" idea worked out. The loss of precipitation from the weak lift that developed in the spacing between the surface and mid-level low likely deprived the region of several inches of snow. It also allowed for some intrusion of sleet into the greater New York City area for a time until the lift improved.

655 NOUS41 KOKX 271249 PNSOKX CTZ005>012-NJZ002-004-006-103>108-NYZ067>075-078>081-176>179-280049- Public Information Statement National Weather Service New York NY 749 AM EST Sat Dec 27 2025 ...SNOWFALL REPORTS... Location Amount Time/Date Provider ...Connecticut... ...Fairfield County... 4 NNW New Fairfield 9.1 in 0409 AM 12/27 Trained Spotter Bridgeport Airport 7.1 in 0700 AM 12/27 Official NWS Obs 2 ENE New Canaan 7.1 in 0528 AM 12/27 Trained Spotter Bethel 6.5 in 0700 AM 12/27 Emergency Mngr 4 SSE Easton 6.2 in 0600 AM 12/27 Public 1 W Stamford 5.9 in 0605 AM 12/27 Trained Spotter 1 NNW Stamford 5.7 in 0100 AM 12/27 Trained Spotter ...Middlesex County... Clinton 8.0 in 0645 AM 12/27 Broadcast Media 1 SW Westbrook 7.7 in 0240 AM 12/27 Trained Spotter ...New Haven County... 1 NNW Meriden 9.0 in 0350 AM 12/27 Trained Spotter 1 ENE North Haven 7.7 in 1220 AM 12/27 Trained Spotter 2 NW Hamden 7.3 in 0647 AM 12/27 Public 4 SSE Durham 7.1 in 0200 AM 12/27 Public 3 ENE Branford 6.5 in 0647 AM 12/27 Public 3 ENE Branford 6.4 in 1201 AM 12/27 Public 1 NW Ansonia 6.0 in 0531 AM 12/27 Public ...New London County... 5 SSE Salem 7.0 in 0603 AM 12/27 Public New London 6.5 in 1139 PM 12/26 Trained Spotter Ledyard Center 5.5 in 0100 AM 12/27 Trained Spotter ...New Jersey... ...Bergen County... 1 S River Edge 3.3 in 0720 AM 12/27 Public 2 NNE Franklin Lakes 3.2 in 0138 AM 12/27 Public ...Essex County... 2 NE Springfield 3.0 in 0400 AM 12/27 Public 1 NW Newark 2.3 in 1226 AM 12/27 Public ...Hudson County... Harrison 4.0 in 0442 AM 12/27 CO-OP Observer Hoboken 3.9 in 0700 AM 12/27 Trained Spotter ...Union County... Newark Airport 4.2 in 0700 AM 12/27 Official NWS Obs 1 NW Cranford 3.0 in 0717 AM 12/27 Public 1 NE Union 3.0 in 0200 AM 12/27 Public ...New York... ...Bronx County... 1 NNE Fordham 4.3 in 0400 AM 12/27 Public ...Kings County... 1 SSE Williamsburg 4.3 in 0715 AM 12/27 Public 1 N Bay Ridge 3.1 in 0603 AM 12/27 Public ...Nassau County... Massapequa 4.1 in 0700 AM 12/27 Amateur Radio 1 N Centre Island 4.0 in 0529 AM 12/27 Public 1 SW Levittown 4.0 in 0202 AM 12/27 Public Carle Place 3.1 in 0645 AM 12/27 Amateur Radio 1 SW Elmont 2.0 in 1250 AM 12/27 Trained Spotter ...New York (Manhattan) County... Central Park 4.3 in 0700 AM 12/27 Official NWS Obs ...Orange County... 2 SSW Stewart Airport 5.7 in 0724 AM 12/27 Public 2 E Highland Mills 5.2 in 0130 AM 12/27 Public 2 NW Stewart Airport 5.0 in 0628 AM 12/27 Amateur Radio Monroe 5.0 in 0500 AM 12/27 Trained Spotter 2 SSW Stewart Airport 5.0 in 1212 AM 12/27 3 WNW Warwick 4.0 in 0603 AM 12/27 Trained Spotter ...Putnam County... 2 W Putnam Valley 5.7 in 0605 AM 12/27 NWS Employee ...Queens County... 1 WSW Howard Beach 4.6 in 0701 AM 12/27 Broadcast Media NYC/JFK 4.1 in 0700 AM 12/27 Official NWS Obs NYC/La Guardia 4.1 in 0700 AM 12/27 Official NWS Obs ...Suffolk County... Babylon 7.5 in 0645 AM 12/27 Amateur Radio Orient 7.5 in 0615 AM 12/27 Trained Spotter North Patchogue 6.8 in 0109 AM 12/27 Public Islip Airport 6.6 in 0700 AM 12/27 Official NWS Obs Upton (NWS Office) 6.5 in 0700 AM 12/27 Official NWS Obs Stony Brook 5.8 in 0700 AM 12/27 Trained Spotter 1 WNW Sound Beach 5.8 in 0700 AM 12/27 Public 2 E Flanders 5.8 in 1120 PM 12/26 Public 1 SSE Bohemia 5.6 in 0550 AM 12/27 Trained Spotter 2 SE Ridge 5.6 in 1159 PM 12/26 NWS Employee Deer Park 5.3 in 0600 AM 12/27 Trained Spotter 1 WSW Poquott 5.2 in 0425 AM 12/27 NWS Employee Sayville 5.1 in 0700 AM 12/27 NWS Employee 1 ESE East Patchogue 5.1 in 0541 AM 12/27 NWS Employee 1 SSE Bohemia 4.7 in 1205 AM 12/27 Public 2 S Commack 4.5 in 0145 AM 12/27 Public 1 N Smithtown 4.3 in 1200 AM 12/27 Trained Spotter Stony Brook 4.3 in 1155 PM 12/26 Trained Spotter 1 ENE Commack 4.0 in 1140 PM 12/26 Broadcast Media 1 E Kings Park 3.6 in 1259 AM 12/27 Public Medford 3.5 in 0723 AM 12/27 Amateur Radio ...Westchester County... Armonk 6.4 in 0200 AM 12/27 Trained Spotter 2 ENE Peekskill 6.1 in 1200 AM 12/27 Trained Spotter 1 E Pelham Manor 2.8 in 0736 AM 12/27 Public

Snow/sleet mixture.

At 7 pm. It’s probably around 2”-3”.

Light sleet in Larchmont.

Thank you, Volcanic Winter.

Two photos from this evening:

Moderate to heavy snow has developed in the Larchmont area.

0.5" in Larchmont, NY.

First NAM bust incoming... According to the 12/26 18z NAM (using four algorithms on Bufkit), 1.2"-1.5" of snow was expected at Binghamton before the transition to several hours of sleet. Binghamton has seen snowfall approaching 3.0" as of 5:05 pm with moderate continuing snow to fall.

Light-to-moderate snow in Larchmont. The ground is coated.

Light snow has reached Larchmont in southern Westchester County.

Snow is now approaching the New York City region. Snow is currently falling in northeastern Pennsylvania, parts of southeastern New York State and extreme northwestern New Jersey. The snow will fall moderately to even heavily for a time during the first half of tonight. Sleet or freezing rain could mix in toward the end of the storm in parts of the region. A general 4"-8" snowfall is likely in and around the New York City area. Some locally higher amounts are possible. Areas to the south and west of New York City will see a larger share of precipitation fall as sleet. As a result from central New Jersey southward, snow accumulations will be noticeably lower. Philadelphia could pick up a coating to 2" of mainly sleet. The storm will be followed by a chilly weekend. A storm cutting to the Great Lakes could bring some rain and milder weather on Monday before cold air returns to close out December. The closing days of December will likely be colder than normal. December 2025 will very likely finish with a maximum monthly temperature below 60° in New York City. The last time that happened was in 2019 when the monthly high was 58°. If 2025 has a monthly high below 60°, that would be only the fifth such occurrence since 2000 (2003, 2004, 2005, and 2019 are the cases since 2000). The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.8°C for the week centered around December 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.40°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions will likely continue through at least mid-winter. The SOI was -0.88 today. The preliminary Arctic Oscillation (AO) was -0.705 today. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal December (1991-2020 normal). December will likely finish with a mean temperature near 34.0° (5.1° below normal). That will make December 2025 the coldest December since 2010 when the monthly mean temperature was 32.8°. It would also make 2025 the third coldest December since 2000. Supplemental Information: The projected mean would be 3.4° below the 1981-2010 normal monthly value.

I'll do the 18z HRRR, too. I think that model is often cold-biased, but let's see how it does. 18z HRRR. I will also compare the 18z NAM and 18z HRRR. My point estimates: Bridgeport: 8.0" Islip: 7.9" New York City (Central Park): 5.8" Newark: 4.8"

For fun, let's compare the 18z NAM with the NWS for select locations that provide snowfall reports: 18z NAM: NWS Forecast: I will be looking at the other 18z guidance. For now, I still think a general 4"-8" snowfall is likely in and around New York City (including all of the above locations).

Coming back from the New York Botanical Garden and its lonely blooming camellia, and reading the many pages that have accumulated in this thread, it seems that chaos ruled. Seemingly with every model in every cycle, the forecast has changed. Posts proclaimed a confidence-boosting snowfall. Others stripped it all away. Snowfall totals advanced, retreated, and advanced again. There were calls for confidence. There were calls for panic. The furious activity over a few hours suggested that AmWx readers were frantically refreshing their phones the way sailors once scanned the horizon, hoping the weather would make up its mind (or at least those posting on the forthcoming storm would). Reading the alternating encouraging and dampening posts felt like whiplash. By the end of the thread, no one truly could know what to plan for. Reading the ups and downs and twists and turns was like sitting in a plane on final approach while the pilot yanked the controls left, then right, then left again, never really committing to the runway. In fact, in synoptic terms, things have been far less chaotic. Most of the reliable guidance has continued to be a model of fairly impressive consistency for the snow-starved New York City region. The New York City area, Hudson Valley, southwestern Connecticut, and parts of Long Island remain in line for a moderate-to-significant snowfall (4"-8"). The real battle zone where uncertainty and drama have reigned has been southwest of there from central New Jersey southward and northeast of there into Massachusetts. Will Philadelphia be left with only miserable sleet and freezing rain? Will some of the steady snow cross Storrow Drive into downtown Boston? The latest HREF shows that things remain on track. As is typically the case, if one reduces the categories of snowfall by one category e.g., 6"-8" is reduced to 4"-6", one gets a good picture of what is likely at this stage while taking into consideration the modest uncertainty that still exists. Even a two-category reduction would yield 4"-6" for most of New York City. Meanwhile, snow is advancing through western New York State. New York City is poised to see its biggest snowfall since January 28-29, 2022 when 8.5" fell.