December 2025 OBS and Discussion

[MJO812]

27 minutes ago, Roger Smith said:

I would bet when it warms up slightly for Christmas Eve into the 25th, it will get very foggy until the warm sector is suppressed south. Foggy and 48-52 F temps, Santa will not find every house. Oh right, I'm supposed to pretend Santa doesn't exist. Forgot about that. 

You mean upper 30s to low 40s.

[nycwinter]

sun angle is increasing looked kinda brighter today..

[uofmiami]

40 minutes ago, nycwinter said:

sun angle is increasing looked kinda brighter today..

Blowtorch effect

[Brian5671]

Sunset times are already increasing went from 4:24 here  around dec 10th to 4:28 today

[cleetussnow]

41 minutes ago, Brian5671 said:

Sunset times are already increasing went from 4:24 here  around dec 10th to 4:28 today

At this rate the sun will never set! 

[MJO812]

The Weather Channel already has it lol

 

[MANDA]

Anyone check out the cold over NW Canada?  Currently -40's to -50's F over Yukon and NWT.  Even a few spots at -60F currently.

Mid to LR forecasts continue to build the cold over the next week.

Where it goes beyond that is the question.  Does it stay bottled up in Canada and slide more east than south or does in make a run south into the U.S. either is pieces or a large Arctic plunge?  I think all options are on the table but something worth following.

 

[NorthShoreWx]

2 hours ago, psv88 said:

I would rather have your latitude and sound proximity during big storms than fake cold 

That's when it giveth...although it isn't always a slam dunk.  We had about the same SWE as everybody else on 12/26/2010, but only 12" of quite dense accumulation. The screaming winds above the deck pulverized the snowflakes before they reached the ground.

[TheClimateChanger]

 

[MANDA]

14 minutes ago, TheClimateChanger said:

 

Been a while since the coldest air in the hemisphere has been on our side of the pole.  We’ll see how things play out as we move through early January.  

[donsutherland1]

A weak system will bring some light snow possibly mixing with or ending as some light rain or drizzle in some areas tomorrow.  New York City will likely see a coating to 1". A 1"-3" snowfall is possible in the northern and western suburbs where it will be somewhat colder.

The temperature will likely remain above freezing throughout the day on Tuesday in New York City. In New York City, only 25.6% of storms have seen measurable snowfall with a daily low of 33° or above with just 9.2% seeing 1" or more snowfall. Almost three-quarters (74.4%) of such events have seen only a trace of snowfall.

Another system could bring precipitation on Friday into Saturday. This system could have more moisture to work with than tomorrow's. 

No exceptionally cold or warm weather appears likely for the first week of astronomical winter. The closing days of December will likely be colder than normal.

December 2025 will 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 +10.59 today. 

The preliminary Arctic Oscillation (AO) was +1.620 today. The PNA was -1.766. That's the lowest winter value since December 24, 2021 when the PNA was -2.084.

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 34.3° (4.8° below normal). 

Supplemental Information: The projected mean would be 3.1° below the 1981-2010 normal monthly value. 

 

[bluewave]

1 hour ago, TheClimateChanger said:

 

Extreme temperature gradients in Asia and North America with multiple 4 to 5 sd jet streaks.

Overall, the Northern Hemisphere is very warm for this time of year due to the warmth covering more real estate.

So it will be hard to trust individual model storm details beyond 72-96 hrs. Since a tiny shift in the gradient between the strong 500 mb mid and high latitude blocking ridges can cause a big swing in local sensible weather. 

It’s looking like a very active pattern with the details to be worked out in the short term.

 

[Roger Smith]

4 hours ago, MJO812 said:

You mean upper 30s to low 40s.

Probably the way models are trending, it's becoming a question of whether the milder air ever makes it past central NJ but I think temps will spike at around 45F for a few hours late Christmas Day, then slide down into high 20s setting up a solid wall of icy resistance when the Friday wave drops southeast, could lead to a much heavier snowfall than forecasts are currently saying (can't say record because it's 78 years after 12-26-1947). A few days ago it was looking like a very mild two days 24th-25th and now it's looking more like a couple of hours of slight warming. Encouraging when the models bust on the warm side. 

[PhiEaglesfan712]

51 minutes ago, Roger Smith said:

Probably the way models are trending, it's becoming a question of whether the milder air ever makes it past central NJ but I think temps will spike at around 45F for a few hours late Christmas Day, then slide down into high 20s setting up a solid wall of icy resistance when the Friday wave drops southeast, could lead to a much heavier snowfall than forecasts are currently saying (can't say record because it's 78 years after 12-26-1947). A few days ago it was looking like a very mild two days 24th-25th and now it's looking more like a couple of hours of slight warming. Encouraging when the models bust on the warm side. 

What about the 12/26/2010 snowstorm?

[qg_omega]

4 hours ago, bluewave said:

Extreme temperature gradients in Asia and North America with multiple 4 to 5 sd jet streaks.

Overall, the Northern Hemisphere is very warm for this time of year due to the warmth covering more real estate.

So it will be hard to trust individual model storm details beyond 72-96 hrs. Since a tiny shift in the gradient between the strong 500 mb mid and high latitude blocking ridges can cause a big swing in local sensible weather. 

It’s looking like a very active pattern with the details to be worked out in the short term.

 

Historic 1,000 year cold building

https://x.com/ryanmaue/status/2003182403121287452?s=46&t=m4Eqkekadb-JCXTm7k-Txg

[Roger Smith]

3 hours ago, PhiEaglesfan712 said:

What about the 12/26/2010 snowstorm?

1947 was 26.4" (26.1" on 26th) and 2010 was 20.0" (12.2" 26th + 7.8" 27th). That 7.8" portion is the daily record for the 27th. The 12.2" on 26th would have been a daily record on every day of December except the 15th (12.7" fell in 1916), the 20th (15.5" fell in 1948), but even without 1947, not  the 26th .... 18 inches fell in 1872 on Dec 26th during a very cold spell. Boxing Day seems good for snow, I think Don showed it was the most likely date in December to see measurable snow, and other significant falls include 7.0" in 1890, and 11.2" in 1933. In 1969 there was 6.3" over the 25th and 26th. 

The three largest December totals for two days all include the 26th. 

[Krs4Lfe]

Fortunately, it seems that the big warmup coming around Christmas and through new years was overestimated by the models. It looks like most of the northeast and mid Atlantic will remain with near normal temperatures and New England will remain a bit colder than normal. That being said the warmth during Christmas week across the country is literally like the inverse of the Arctic air outbreak during Christmas 2022. But either way, this is almost just as impressive with temperatures in the 80s all the way up to Nebraska today. Spring to  summer like weather this week for much of the heartland and the south. Fortunately, it doesn’t appear that will be reaching us during this last week of December. Hopefully all the record cold air bottled up in Canada in Alaska can spill down next month across the country and bring some renewed snowfall chances. Because aside from our snowfall chances here in the northeast, much of the country will remain warm and dry for the foreseeable future.

[wthrmn654]

My sister in Tennessee has been having wild temperatures lately,  65 during day lower 20s at night.  Or 10 at night and 58 next day. 

[MJO812]

Lets see if we can get Sunday's storm to shift south and colder

 

[MJO812]

Cmc would have showed a huge snowstorm past 240.

Models are really cold going forward. The warm pattern is gone.

[bluewave]

6 hours ago, MJO812 said:

Cmc would have showed a huge snowstorm past 240.

Models are really cold going forward. The warm pattern is gone.

We haven’t seen a clipper pattern like this in a long time. I am wondering if the benchmark KU track can become activated again at some point in January or February? That’s what we would need to get back closer to mid 20s seasonal snowfall. 

[MJO812]

1 minute ago, bluewave said:

We haven’t seen a clipper pattern like this in a long time. I am wondering if the benchmark KU track can become activated again at some point in January or February? That’s what we would need to get back closer to mid 20s seasonal snowfall. 

We need the old days back. Juiced up clippers and Miller As.

[bluewave]

49 minutes ago, MJO812 said:

We need the old days back. Juiced up clippers and Miller As.

We would have to go back to the 1970s or 1980s to get close to 25” from Newark out to Islip without at least a cat 1 NESIS KU event.

This pattern is very unusual in that we are getting a strong ridge across the CONUS and a strong -NAO at the same time. So the Northern Stream is active for both rain like we saw last Friday and snow with the clipper before that.

Have my doubts that we could get to 25” just on snowy clippers alone alternating with warmer storms and more rain or mix.

I think it’s going to take a KU NESIS event to get us over the finish line.

 

 

[EastonSN+]

55 minutes ago, MJO812 said:

We need the old days back. Juiced up clippers and Miller As.

The old days have been back since 2018. 2019 till now is a reflection of 1970 through 1999. Although 25 of the 30 winters had below average snowfall we did get great snowstorms in 1978, 1983, 1993, 1994 and 1996. 

[CPcantmeasuresnow]

31.1 with light/moderate snow. Eyeballing 1.5-2 inches. Will measure at 9

[SnoSki14]

Grass is covered but it's mostly wet. 33F 

 

[SACRUS]

34/32  light mainly snow - grass and surfaces just about covered.  In what will now turn out to be a 2 days warmup Christmas Eve and christmas day, followed by colder overall Dec 27 - Jan 4th with some deep cold around the 39 - Jan 3rd.  

 

12/23:  Light snow mix
12/24 - Christmas Day :  Warmer than normal mid / upper 40s perhaps 50
12/26  - 12/27 :   Light  - moderate snowfall (see the thread)
12/28 - 1/4 :  Overall colder than normal strong cold 12/29-12/30 , 1/1-1/4 - hint of storm threats in this period
1/5 - Beyond :  Moderation to / above normal

 

[bluewave]

17 hours ago, MANDA said:

Anyone check out the cold over NW Canada?  Currently -40's to -50's F over Yukon and NWT.  Even a few spots at -60F currently.

Mid to LR forecasts continue to build the cold over the next week.

Where it goes beyond that is the question.  Does it stay bottled up in Canada and slide more east than south or does in make a run south into the U.S. either is pieces or a large Arctic plunge?  I think all options are on the table but something worth following.

 

We have a shot at our first single digits of the season in early January near the coast. 

 

[SACRUS]

Records:

Highs:

EWR: 67 (1990)
NYC: 66 (1990)
LGA: 66 (1990)
JFK: 63 (2015)


Lows:

EWR: 7 (1989)
NYC: -1 (1883)
LGA: 7 (1989)
JFK: 8 (1989)

Historical:

 

1811 - A cold storm hit Long Island sound with a foot of snow, gale force winds, and temperatures near zero. During the storm many ships were wrecked, and in some cases entire crews perished. (David Ludlum)


1908: This was the largest December snowstorm Richmond has ever had with 17.2 inches of snow on the 22nd and 23rd. 17.2 inches, Dec. 22-23, 1908-The new electric technology of the day was no match for the heaviest December snowfall on record. As The Times-Dispatch reported: “Reports from different parts of the city showed that many frail structures had toppled in: giant trees, loaded with tons of snow, crashed in: electric wires, unable to stand the strain and burden, snapped, more than 1,300 telephones being thrown out of commission. Telegraph wires followed, the service being interrupted early in the day, and all trains were thrown out of gear, coming in several hours behind schedule time.” It was a wet snow that stuck to the trees and pulled many trees down doing much damage to the Richnond area. Washington DC recorded 11.5 inches of snow. (Ref. Richmond Newspaper)Other December Snows
 

1921: An estimated F3 tornado struck the town of Clarkedale, Arkansas, killing six and injuring 60 others. Four people died in the destruction of the Banks and Danner store, where 50 people were doing their Christmas shopping.

1955 - The barometric pressure dipped to 28.97 inches (981 millibars) at Boise ID, an all-time record for that location. (The Weather Channel)

1982 - A major winter storm struck Colorado producing heavy snow and blizzard conditions. A record two feet of snow was reported at Stapleton Airport in Denver, which was shut down for 33 hours. Up to 44 inches of snow fell in the foothills surrounding Denver. The storm hurt the ski industry as skiers were unable to make it out of Denver to the slopes, and the closed airport became a campground for vacationers. (23rd-25th) (The Weather Channel) (Storm Data)

1983 - The temperature plunged to 50 degrees below zero at Williston ND to equal their all-time record. Minneapolis MN reported an afternoon high of 17 degrees below zero, and that evening strong northerly winds produced wind chill readings of 100 degrees below zero in North Dakota. (The National Weather Summary)

1987 - A winter storm brought heavy snow to the Central Rockies, and also spread a blanket of snow across the Middle Missouri Valley in time for Christmas. Snow and high winds created near blizzard conditions in Wyoming. Snowfall totals in Wyoming ranged up to 25 inches at Casper, with four feet of snow reported at the Hogadon Ski Resort on Capser Mountain. The Wolf Creek Ski Resort in Colorado received 26 inches of snow. Totals in the Middle Missouri Valley ranged up to 16 inches at Alpena SD, with 14 inches at Harrison NE. Strong winds ushered unseasonably cold air into the southwestern U.S. Canyon winds gusting to 100 mph created ground blizzards in Utah. (The National Weather Summary) (Storm Data)

1988 - Low pressure in the Upper Midwest produced strong and gusty winds across the Great Lakes Region and the Ohio Valley. Winds in Ohio gusted to 47 mph at Cincinnati, and reached 51 mph at Cleveland. (The National Weather Summary) (Storm Data)

1989 - An historic arctic outbreak spread to the Gulf Coast Region, and a total of 122 cities across the central and eastern U.S. reported record low temperatures for the date. Forty-one of those cities reported record lows for the month of December, with some cities breaking December records established the previous morning. Morning lows of 11 degrees at New Orleans LA and Lake Charles LA, 4 degrees below zero at San Angelo TX, and 26 degrees below zero at Topeka KS, established all-time records for those four locations. Yankton SD was the cold spot in the nation with a morning low of 31 degrees below zero. A storm system moving across the Florida peninsula and along the Southern Atlantic Coast produced high winds and record snows along the Carolina coast. Snowfall totals of 15 inches at Wilmington NC and 13.3 inches at Cape Hatteras NC were all-time records for those two locations.

 

1998: A major ice storm struck central and southeast Virginia and much of North Carolina beginning on Wednesday, December 23, and lasting until Christmas Day morning. Icy conditions caused injuries from slips and falls and numerous vehicle accidents. Ice accumulations of up to an inch brought down trees and power lines. Outages were so widespread with 400,000 customers were without power on Christmas Eve. Some people were without power for up to ten days. 

 

2009 - Severe storms and heavy rainfall were associated with the same storm that brought blizzard conditions to the central parts of the U.S. on December 23rd and 24th. At least one death in Louisiana was blamed on the heavy rainfall and storms. There were 35 preliminary tornado reports and 34 hail and wind reports along the Gulf Coast over the 2-day period. The 10-year average number of tornadoes across the country in December is 36. (NCDC)

 

2010: December Pacific Storm- A series of Pacific storms slammed into the Pacific Coast on December 17-23, creating epic run and snowfall accumulations. One to 2 feet of rain brought flooding, mudslides, road closures, and evacuations to lowland areas of southern California, while 4-13 feet snow buried western mountains.(Ref. Weatherwise U.S. Weather Highlights of 2010 page 3)

[SACRUS]

 

Ridge pulls west cold collapses into the GL/MW and NE between Dec 29 - Jan 4