December 2025 OBS and Discussion

[lee59]

I'm not sure how much it has affected the UHI but the city skyline has changed a lot in the past 20 or so years. Many more skyscrapers, Western Brooklyn and Queens are like a continuation of Manhattan. So I would think this would have  at least some affect on the UHI

 

 

[sussexcountyobs]

Snow continues here. Maybe 2" on unpaved surfaces. 1" on paved surfaces.  Road covered again after plow came by an hour ago. Will go shovel driveway in a bit. 32

[MJO812]

Christmas miracle

[lee59]

1 minute ago, sussexcountyobs said:

Snow continues here. Maybe 2" on unpaved surfaces. 1" on paved surfaces.  Road covered again after plow came by an hour ago. Will go shovel driveway in a bit. 32

What a difference here, 44 and light rain

[sussexcountyobs]

1 minute ago, lee59 said:

What a difference here, 44 and light rain

Where are you ?

[Fozz]

6 minutes ago, MJO812 said:

Christmas miracle

I wish this wasn’t fantasyland.

[bluewave]

43 minutes ago, lee59 said:

I'm not sure how much it has affected the UHI but the city skyline has changed a lot in the past 20 or so years. Many more skyscrapers, Western Brooklyn and Queens are like a continuation of Manhattan. So I would think this would have  at least some affect on the UHI

 

 

Not enough for you to notice much of a change in Brooklyn and Queens sensible temperatures since 1980 had the CO2 levels remained steady instead of rapidly climbing. The recent development last 20 years in Western Brooklyn and Queens is a drop in the bucket compared to the overall UHI footprint of NYC which really expanded between the 1890s and 1960s.
 

1 hour ago, NorthShoreWx said:

I've always agreed with all of this.  I just don't see it as settling the main question 

Add 15-20% to snowfall totals from the late 1800s through the 1980s and the long term downward decline becomes even steeper.

[brooklynwx99]

euro is a nice moderate event, comes in more amped with the TPV leaning more southwest 

[sussexcountyobs]

Still some flakes falling, but it's basically over. 1.8" total. 32.4

5.1" season total so far.

[TJW014]

Moderate rain. Very few wet flakes/white rain mixing in.  

[lee59]

53 minutes ago, sussexcountyobs said:

Where are you ?

Long Island

[wdrag]

Wantage NJ (this southern part at 740' MSL). 1.8" final-wet clingy snow.  Less on driveway and virtually none on paved roads now... temp rising to 32.4F. 

[sussexcountyobs]

Kudos to Vernon Township DPW. They are in my neighborhood now. 2nd time plowing and salting. Roads are perfect.

[eduggs]

Turned into a pretty snowy evening for NW burbs especially with some elevation. As already mentioned, the NAM, GFS, and ECM did pretty good along the southern periphery of snow. HRRR and RGEM not so much - too warm.

Apart from the ECM and ECM-AI (haven't seen?), 18z wasn't great for this weekend's potential event.

[ForestHillWx]

Interesting micro-climate observation out my way; as I climbed in elevation north of 287/78 interchange on 206, it flipped to heavy snow about 1/4 mile south of my home.

1/2” on all surfaces, even pavements. 

[eduggs]

Some modeling shows possible snow showers or squalls tomorrow. Something to keep an eye on... despite the lack of "snowstorms" so far this year, I've seen snow a lot more to date than the past few years. The vibe feels different.

[lee59]

55 minutes ago, bluewave said:

Not enough for you to notice much of a change in Brooklyn and Queens sensible temperatures since 1980 had the CO2 levels remained steady instead of rapidly climbing. The recent development last 20 years in Western Brooklyn and Queens is a drop in the bucket compared to the overall UHI footprint of NYC which really expanded between the 1890s and 1960s.
 

Add 15-20% to snowfall totals from the late 1800s through the 1980s and the long term downward decline becomes even steeper.

I agree between the 1890s and 1960s NYC expanded a lot and it keeps getting bigger. Maybe it isn't substantial but I wouldn't call all that building of skyscrapers a drop in the bucket. What makes me even bring it up is when I cross the Throgs Neck bridge and look toward the city I see the Manhattan skyline but then to the south you see the Brooklyn and Queens skyline and it looks like another  large city was built.

[bluewave]

48 minutes ago, lee59 said:

I agree between the 1890s and 1960s NYC expanded a lot and it isn't getting any better. Maybe it isn't substantial but I wouldn't call all that building of skyscrapers a drop in the bucket. What makes me even bring it up is when I cross the Throgs Neck bridge and look toward the city I see the Manhattan skyline but then to the south you see the Brooklyn and Queens skyline and it looks like two more large cities were built.

The increase in development in Western Brooklyn and Queens last 20 years in relation to the totality of the existing UHI footprint is still very small compared the increasing CO2 forcing over the same period. Drop in the bucket for sensible temperatures but a big shift to the character of those neighborhoods that have more high rises than they used to. The skyscrapers replaced already dense low rise urban development that was there previously driving the UHI. It’s not like the new development is replacing a rural area that was great for radiational cooling before 2004.

 

[North and West]

Christmas miracle

But




.

[Stormlover74]

5 minutes ago, North and West said:

But




.

what say you?

@Santa Claus

[Jersey_Snowhole]

1 hour ago, MJO812 said:

Christmas miracle

I’ll take things that will never happen for 1,000 Alex. 

[mob1]

26 minutes ago, eduggs said:

Some modeling shows possible snow showers or squalls tomorrow. Something to keep an eye on... despite the lack of "snowstorms" so far this year, I've seen snow a lot more to date than the past few years. The vibe feels different.

For skiers, this has been a fantastic start to the season. Belleayre is nearly fully open, which is exceedingly rare for this time of year, and VT is faring extremely well.

 

In general, even if nothing pans out, I'd rather cold with at least the prospects of some snow threats than warmth. It's exciting and the emotional roller coaster is part of it, it's similar to how I root for terrible sports teams (something about hope being eternal). 

[coastalplainsnowman]

11 minutes ago, Jersey_Snowhole said:

I’ll take things that will never happen for 1,000 Alex. 

I'd love to know how strongly correlated a snowfall prediction 360 hours out is to actual results.  I know we like to joke that if it's on there at 360 that's bad because that means it won't happen, but it's probably just a wee bit better to be in the jackpot 360 hours out than for it to be showing no storm?  Or is the correlation so weak as to be negligible?  At what point is it better than negligible?  10 days?  8 days?   I imagine those results exist somewhere?  When I'm retired someday I'm going to have a lot of fun messing around with this sort of data.

[MANDA]

2 hours ago, ForestHillWx said:

Interesting micro-climate observation out my way; as I climbed in elevation north of 287/78 interchange on 206, it flipped to heavy snow about 1/4 mile south of my home.

1/2” on all surfaces, even pavements. 

Same here.  Left Chatham about 4:00 and it was 41 with light to some moderate rain.  They were salting the roads like it was the end of days.  Never snowed down there and even if it had dumping salt at 4:00 was going to do nothing even if it switched to snow by 6.  Would have been mostly washed away.

Took back roads home (Sussex Turnpike) and once I got to Randolph it switched to snow like someone flipped a switch.  Snow, sometimes heavy rest of the way home.  By the time I got home at 5:30 (made a stop) all local roads were snow covered.  My rural not well traveled street had been plowed.  Snow ended about 7:00.  Took measurement at that time and had .90" as an event total.  Currently sitting at 1.6" for the season.  Temperature hovered right around 32 during the snowfall but once it ended it bounced up to 34.5.  About 1/2" remains on the deck at 9:30 due to compaction and some melting.  Nice little event.  Spoke to a friend up in Newton and it was pretty nasty up on the side roads up that way.

[WestBabylonWeather]

Keep hope alive Mr metfan. Eventually we will get one 

[Nibor]

2 hours ago, Jersey_Snowhole said:

I’ll take things that will never happen for 1,000 Alex. 

Brave. Some might say the bravest statement. Too bad Alex isn’t here to witness your bravery. 

[Krs4Lfe]

Sometimes it seems hard to envision a sharp weather pattern change when you’re in a totally opposite pattern at the moment. I remember how cold December 2022 was, especially during Christmastime but then we had straight 50s and 60 degrees right through new year. Patterns can flip on a dime, for better or for worse. The cold has been quite enjoyable but we all know it can’t last forever. It would be a bit unreasonable to believe January won’t at least start out warm. Maybe it doesn’t end up that way in the end, but very likely it ends up warm just by the sheer nature of this cold pattern can’t stick around forever  

[JerseyWx]

6 hours ago, bluewave said:

This is due to the overall climate warming since the 1970s and not an expansion of UHI. Even cooler surrounding areas are wall to wall AC usage now from May to September when they weren’t in the past. The warming in rural, suburban, and urban areas has been proportional. 

People will say it's my "heat tolerance," but out my way I seldom use the AC in May and September, outside of short stretches.  In recent years we've even gone well into June without it.  Before we got that heatwave this past June in fact it was quite cool.  The city is outrageous with how it retains heat.  Sometimes I see they are close to 90 at midnight whereas I'll be in the mid 70's.

[donsutherland1]

New York City finished December 1-10 with a mean temperature of 34.1F (1.2C). That was the coldest first 10 days of December since 2007 and sixth coldest since 2000.

A quick look at the guidance shows that a light snow event (probably 1"-3") across the New York City area is likely on Sunday. Given how snow events have been challenging to come by in recent years, to some it might seem like a big event. Even the previously bone-dry NBM shows 0.12" QPF. 

[bluewave]

7 hours ago, JerseyWx said:

People will say it's my "heat tolerance," but out my way I seldom use the AC in May and September, outside of short stretches.  In recent years we've even gone well into June without it.  Before we got that heatwave this past June in fact it was quite cool.  The city is outrageous with how it retains heat.  Sometimes I see they are close to 90 at midnight whereas I'll be in the mid 70's.

I grew up in Long Beach on the South Shore and we only needed the AC a handful of times back in the 1970s. First for the August 1973 heatwave and then the July 1977 heatwave. We gradually increased the AC usage during the 1980s and especially the early 1990s.

By the time we reached 2010, we had three ACs running much of the time compared to only one in the 1970s. Plus there was a rapid expansion of central AC even in Long Beach when it was a rarity near the shore in the 1970s. This is one of the reasons that HVAC is such a good career opportunity for people due to the increased demand in a warming world.

As for the UHI issue, there was a 10°+ difference between NYC during 1896 heatwave and the surrounding countryside. This mostly occurs with summer heatwaves where the city absorbs more heat during the day. It also occurs during calm and clear nights with radiational cooling.

The growth of skyscrapers in Western Brooklyn and Queens certainly changes the character of the neighborhood and of course you can see the change in the skyline since around 2004.

But prior to that that area had densely packed lower rise buildings built of bricks. These new high rises are mainly glass and steel which absorb significantly less solar energy than bricks do.

Plus a cluster of tall buildings will create a big area of shade which prevents the streets and sidewalks from absorbing as much heat as they did with smaller buildings with less shadows.

The warmest parts of NYC are in Queens near spots like Corona were small to medium size brick structures dominate. So changing from lower rise brick and concrete structures to skyscrapers may not change the UHI much in Western Brooklyn and Queens to really be noticeable to residents there. That’s why I said a drop in the bucket to what was already one of the largest UHI zones in North America.

The rural and suburban areas have warmed at a similar rate to places like Corona Queens over the years. So this is why both areas require more summer AC usage than they did during the 1970s.

My guess is that the higher dewpoints and maybe stronger winds are probably why a rural spot like the Charlotteburg Reservoir has seen a steeper increase in low temperatures than LGA since 1981.