December 2025 OBS and Discussion

[bluewave]

1 hour ago, jm1220 said:

And then Fri’s rain will come with strong winds so by the end we’ll just have the dirty mall piles. Oh well. 

2010-2011 was some of the biggest snow piles my whole time in Long Beach where the old amusement park used to be.

[Brian5671]

42 minutes ago, bluewave said:

2010-2011 was some of the biggest snow piles my whole time in Long Beach where the old amusement park used to be.

some of them here in parking lots lasted til around May 1st

[North and West]

Wash, rinse, repeat! Same holidays pattern as always!

Have yourself a merry little miserableness


.

[bluewave]

20 hours ago, jetrz said:

Today was the 20th consecutive day of below normal temperatures at Central Park. Anyone know where to find out how long its been since we've had such a streak?

This is the first 20 day below normal streak for the new 1991-2020 climate normals era.  xmACIS2 reset all the prior period departures to the 1991-2020 climate normals. So we don’t have the earlier departures based on 1981-2010, 1971-2000, 1961-1990, 1951-1980..etc.   

[SACRUS]

5 minutes ago, bluewave said:

This is the first 20 day below normal streak for the new 1991-2020 climate normals era. XMACIS2 reset all the prior period departures to the 1991-2020 climate normals. So we don’t have the earlier departures based on 1981-2010, 1971-2000, 1961-1990, 1951-1980..etc.   

The period Dec 18, 2000 - Jan 10, 2001 was for EWR.  Will check NYC.

[SACRUS]

Also Jan 7, 2004 - Feb 3, 2004 at EWR consecutive below daily dep

[Stormlover74]

45 minutes ago, Brian5671 said:

some of them here in parking lots lasted til around May 1st

What did you do to snowhole?  Lol

[gravitylover]

2 hours ago, bluewave said:

2010-2011 was some of the biggest snow piles my whole time in Long Beach where the old amusement park used to be.

That was a fun place 50 years ago. 

[coastalplainsnowman]

1 hour ago, Brian5671 said:

some of them here in parking lots lasted til around May 1st

I remember years asking on this forum (or probably a predecessor forum) what's the longest they've seen a plowed pile of snow last.  Someone within this forum's geographic area responded June - I want to say it wasn't plowed but rather snow that had been somehow packed in somewhere in the shade on the side of some mountain.  June!

[Brian5671]

1 minute ago, coastalplainsnowman said:

I remember years asking on this forum (or probably a predecessor forum) what's the longest they've seen a plowed pile of snow last.  Someone within this forum's geographic area responded June - I want to say it wasn't plowed but rather snow that had been somehow packed in somewhere in the shade on the side of some mountain.  June!

some of those mall piles can last forever too especially if out of the sun.   I've never seen June around here...usually into April into some of our snowier winters but 2010-11 was special

[coastalplainsnowman]

1 hour ago, Brian5671 said:

some of them here in parking lots lasted til around May 1st

I prefer the stat of 'most consecutive days of snowpile' to the 'latest date of snowpile', and the best years to get those are one like this, where we get some decent snowpiles in mid december.  Even with a few modest plowable snows spread out in a favorable way, you can keep replenishing and have a snowpile in one spot from December 14th into April.

[cleetussnow]

29 minutes ago, coastalplainsnowman said:

I remember years asking on this forum (or probably a predecessor forum) what's the longest they've seen a plowed pile of snow last.  Someone within this forum's geographic area responded June - I want to say it wasn't plowed but rather snow that had been somehow packed in somewhere in the shade on the side of some mountain.  June!

Well there was the boston snow mountain 2015  melted in July.  Outside our region but still amazing.

 

 

The "South Boston Snow Farm" refers to temporary piles of cleared snow from Boston's record-breaking winter of 2015, dumped in a South Boston lot, creating a massive, slow-melting mountain of snow

[donsutherland1]

Tomorrow and Friday will be mild days with highs reaching or exceeding 50° in parts of the region. Friday will be the warmer day with highs in the 50s across much of the region. 

A soaking rain is likely tomorrow night and Friday. Much of the region could see a general 0.50"-1.50" of rain.

Behind the storm, the weekend will turn somewhat cooler. No exceptionally cold or warm weather appears likely for the first week of astronomical winter.

The probability that December 2025 will have a maximum monthly temperature below 60° has continued to increase. 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 -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around December 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.33°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely continue through at least mid-winter.

The SOI was -4.26 today. 

The preliminary Arctic Oscillation (AO) was +2.532 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied near 99% 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). 

Supplemental Information: The projected mean would be 3.4° below the 1981-2010 normal monthly value. 

 

[weatherpruf]

9 hours ago, Brian5671 said:

wow Dec 2015 didn't go below freezing once lol

i had tomato seedlings sprouting in the garden. it was so hot i wanted to put the ac on with a house full of guests. heck with that. at least we had some winter this year. hope spring eternal.

[JerseyWx]

1 hour ago, coastalplainsnowman said:

I remember years asking on this forum (or probably a predecessor forum) what's the longest they've seen a plowed pile of snow last.  Someone within this forum's geographic area responded June - I want to say it wasn't plowed but rather snow that had been somehow packed in somewhere in the shade on the side of some mountain.  June!

That seems too much for our region.  I really don't even see how plowed piles could last beyond the end of April around here, unless it was exceptionally cool.  Otherwise, by May the 70's and higher dewpoints would eat any snow alive.

[WestBabylonWeather]

4 hours ago, bluewave said:

2010-2011 was some of the biggest snow piles my whole time in Long Beach where the old amusement park used to be.

I remember. Dump trucks were taking snow away 

[donsutherland1]

Winter 2025-2026 is off to the 37th best start in terms of cold and snow in New York City. Records go back to 1869-1870.

[the_other_guy]

8 hours ago, bluewave said:

One of the more impressive December shifts from colder to warmer across the CONUS since 2000.

 

I said this yesterday. Very erratic

[jm1220]

2 hours ago, WestBabylonWeather said:

I remember. Dump trucks were taking snow away 

2010-11 was by far the best snow cover winter I’ve ever seen. 

[psv88]

20 minutes ago, jm1220 said:

2010-11 was by far the best snow cover winter I’ve ever seen. 

2013-2014 was pretty damn good too. 

[MJO812]

16 minutes ago, psv88 said:

2013-2014 was pretty damn good too. 

Alot of fluffy snowstorms that winter 

[eduggs]

All of the mid-range guidance through day 7 has the thermal boundary too far northeast for us to have much of a shot at snow. Out to day 10 isn't much better. I hope it changes. It's a pretty ugly and repetitive looking longwave setup that would seem to favor New England for snow chances. But it doesn't exactly look warm either after Friday and the real cold is not too far off. But it's sure no fun looking at a huge stagnant ridge over the central US.

[cleetussnow]

3 minutes ago, eduggs said:

All of the mid-range guidance through day 7 has the thermal boundary too far northeast for us to have much of a shot at snow. Out to day 10 isn't much better. I hope it changes. It's a pretty ugly and repetitive looking longwave setup that would seem to favor New England for snow chances. But it doesn't exactly look warm either after Friday and the real cold is not too far off. But it's sure no fun looking at a huge stagnant ridge over the central US.

Not enough blocking to get it done on the GFS.  Its going to be tough to get the snow down this way for a couple weeks with that set up.  
 

but we know it rains on Christmas.  As I say you can se your watch to it.

[NorthShoreWx]

2 hours ago, jm1220 said:

2010-11 was by far the best snow cover winter I’ve ever seen. 

 

1 hour ago, psv88 said:

2013-2014 was pretty damn good too. 

I'll throw in for 2014-2015.

2010-2011 got the deepest, but 2015 was a close second.  Plus we had drifts out back into April.

[NorthShoreWx]

Heads up, there's black ice out there right now.   Be wary on the roads.

[EasternLI]

14 hours ago, brooklynwx99 said:

that -NAO has grown rather significant to end to the month... can see a redeveloper around the 28th or so with lower heights being forced over the NE. hopefully we can trend it stronger and farther west

Still trending on the 00z.

[bluewave]

8 hours ago, the_other_guy said:

I said this yesterday. Very erratic

 

This is going to be one of the strongest -WPO blocks that we have seen for the month of December.

But it’s a different configuration of other factors that we have previously seen with December -WPOs in the past.

This one has a much more amplified Pacific Jet into the PACNW and BC than we have seen before with the historic flooding in those areas. Plus we have an out of phase +EPO and very strong ridge onto the Western US. 

The ridge that was out West is shifting further east leading to the moderation in temperatures across the CONUS.
 

Unique December 2025 500 mb and Pacific Jet stream pattern compared to previous very strong -WPO patterns

 

 

[brooklynwx99]

1 hour ago, EasternLI said:

Still trending on the 00z.

if you retro that Pacific trough a bit more and allow for the ridge axis over the Plain to shift 100mi towards Montana, things become very interesting 

[bluewave]

2 minutes ago, brooklynwx99 said:

if you retro that Pacific trough a bit more and allow for the ridge axis over the Plain to shift 100mi towards Montana, things become very interesting 

Yeah, we would want the ridge in a similar position to what we got with the recent clipper to make things interesting. I am just not sure yet whether the Pacific Jet can relax enough to allow for sufficient retrogression. The time to watch would probably be early in January.

 

[snowman19]

9 minutes ago, bluewave said:

 

This is going to be one of the strongest -WPO blocks that we have seen for the month of December.

But it’s a different configuration of other factors that we have previously seen with December -WPOs in the past.

This one has a much more amplified Pacific Jet into the PACNW and BC than we have seen before with the historic flooding in those areas. Plus we have an out of phase +EPO and very strong ridge onto the Western US. 
 

Unique December 2025 500 mb and Pacific Jet stream pattern compared to previous very strong -WPO patterns

 

 

Chris, are there even any analogs for what the models are projecting for next week into the first few days of January? It’s extremely anomalous like you said…huge Aleutian ridge (-WPO), out of phase +EPO, strong -PNA, -NAO, neutral/negative AO and a massive omega ridge/omega block dead center of the CONUS?