December 2025 OBS and Discussion

[Brian5671]

2 minutes ago, Krs4Lfe said:

Once the block hooks up with the southeast Ridge, like it’s been doing more often than not over the past few years that will keep most of the east US warm. The southeast Ridge is almost always under modeled so I’m not sure it’s a good look.

that would guarantee a couple of weeks of cutters too

[jm1220]

If we have a slightly negative or neutral PNA that would drive a more zonal jet stream, it could work with a -NAO, but a sharply negative -PNA would drive such a deep trough on the west coast that the SE ridge would respond and possibly link with the NAO block. That’s obviously what we want to avoid. 

[wxallannj]

5 hours ago, SACRUS said:

 

Through the 15th / first half of Dec Departure

LGA: -8.6
NYC: -8.6
EWR: -7.9
JFK: - 7.6

Saw that in NYC it was the coldest 15 days of December since 2005.

[Volcanic Winter]

1 hour ago, snowman19 said:

I wasn’t born yet lol but looking back on the weather history, the 1989-90 winter was probably (easily) the most extreme pattern flip we’ve seen in the last 50 years. We went from a record cold arctic tundra starting in November right through the end of December, then got a big cutter on New Year’s Eve and that was all she wrote, light switch flip to an unmitigated torch for all of January and February….

That’s really incredible. Weather and climatology are so fascinating to me, so many variables at any given time producing innumerable outcomes - sometimes resulting in extreme permutations.

I was born in the late 80’s so of course wasn’t around for the extremes of that decade. One of my first vivid weather memories however was the blizzard of 96… not a bad one to have. Was in Monmouth county for that as a kid. 

[snowman19]

21 minutes ago, jm1220 said:

If we have a slightly negative or neutral PNA that would drive a more zonal jet stream, it could work with a -NAO, but a sharply negative -PNA would drive such a deep trough on the west coast that the SE ridge would respond and possibly link with the NAO block. That’s obviously what we want to avoid. 

I believe @bluewave discussed the possibility of that happening (SE ridge hooking up with the -NAO) last week. A -PNA would definitely make that possibility more likely as you said

[EastonSN+]

10 minutes ago, snowman19 said:

I believe @bluewave discussed the possibility of that happening (SE ridge hooking up with the -NAO) last week. A -PNA would definitely make that possibility more likely as you said

Especially if the RNA is closer to the west coast and -2 or less.

Would not happen in a +PNA.

[Krs4Lfe]

28 minutes ago, EastonSN+ said:

Especially if the RNA is closer to the west coast and -2 or less.

Would not happen in a +PNA.

Yeah that's the benchmark to watch. If we see a deeply negative PNA, then rest of winter would probably be similar to winter 2023 and 2024. Big time snow and cold in the west, and warm and mild over here

[NEG NAO]

[North and West]

It was wild to say the least.    Most of the snow was suppressed south however.   Savannah, GA had a 10 inch snowstorm right before Xmas.   Around the 30th-it broke and never came back-Jan/Feb/Mar were absolute infernos

I remember being at my grandparents’ on New Year’s Eve and snow changing to rain. I then remember going to church in January in shorts, and then it snowed in early April.

Best part is that I got to do the weather report for my class the first week of December.

Wild second grade for sure.


.