December 2025 OBS and Discussion

[MJO812]

1 hour ago, SnoSki14 said:

You aren't getting snow in the city next week. High is retreating, low will cut west. Not enough cold out ahead of it either. 

It's a lost cause

Quite possible but its still close to watch it. 

[eduggs]

The surface features aren't driving this outcome. The position and strength of the surface highs and lows follow the upper levels.

The trend over the past 2 days is for the shortwave to not "dig" as far south. The vortmax that passes through the Great Lakes is becoming increasingly prominent. The path of this shortwave and vorticity advection ends up tracking pretty similarly to Sunday's wave that precedes it. That leads to a stronger surface reflection (primary) near Western PA and southeasterly low level flow that quickly changes snow to rain along the coastal plain.

The hope is that maybe guidance is keying on the wrong packet of vorticity and that the models will shift back towards a more favorable trof evolution. As of now this is transitioning towards a SWFE-type event that favors the interior, particularly New England. But it's still close to a wintry outcome... and highly trackable.

[eduggs]

It's difficult to know how significant it is that the GFS op is significantly wetter and further west compared to the GEFS mean. The GEPS and EPS are also a bit southeast and drier. Obviously the averaging-effect decreases the mean precipitation the more you go out in forecast time. But the majority of the individual ensemble members are also well east of the GFS. The op also appears to be a bit faster than ensemble consensus... maybe in response to the sharp Great Lakes shortwave/vortmax that is at the leading edge of the trof.

I suspect the op (maybe higher resolution?) is more accurately resolving the shortwave progression than the ensembles. I expect the ensembles to play catchup, and I don't think we're done trending yet.

[eduggs]

Just noticed that there are still pretty big differences between the CMC and GFS days 4-5 at 500mb. The CMC actually doesn't look too bad aloft... that's a borderline snowstorm to pretty close N&W. The GFS upper levels look like they would support more rain and less snow than depicted. I feel like the GFS will end up more right... hope I'm wrong.

[eduggs]

The 0z UKMET and 18Z ECM-AI squash the shortwave and yield very little precip. At 4.5 days out this possibility is still plausible.

[Snowlover11]

Nothing burger unless you live 45+ Miles NW of nyc.

[MJO812]

1 minute ago, Snowlover11 said:

Nothing burger unless you live 45+ Miles NW of nyc.

Yep

Typical

[SnoSki14]

46 minutes ago, MJO812 said:

Yep

Typical

This set-up would probably work in January with a colder antecedent air mass. Track isn't bad. Fast flow doesn't allow low to amp up and move inland. 

[Krs4Lfe]

2 hours ago, MJO812 said:

Yep

Typical

No reason to have thought otherwise this early in the season. Central Park still waiting for its first freeze. Almost unheard of to enter December without having a freeze. Won’t be confident in any snow depictions until we get some real cold air in the region  

[NEG NAO]

0Z Euro - a few days after mid-week event next weekend) has been showing up on various models last few days-colder airmass to work with-also will be entering MJO phase 8

[wdrag]

While no wind thread today... am getting a tracking thread  started for Tuesday by 930AM, 

[MJO812]

8 minutes ago, NEG NAO said:

0Z Euro - a few days after mid-week event next weekend) has been showing up on various models last few days-colder airmass to work with-also will be entering MJO phase 8

That timeframe should be watched.

[forkyfork]

brutal

[forkyfork]

[Krs4Lfe]

18 minutes ago, forkyfork said:

That’s the real killer here because if there was more sea ice, then it definitely would’ve been colder and northern Canada, which bleeds down to the rest of Canada and is the source region for the Northeast’s cold air. With such a low arctic sea ice, it limits the amount of cold air that can be tapped into in the northeast and that ends up screwing over locations along the coast until climatology becomes cold enough later in December and January. That’s just one of the many reasons why Tuesday’s storm will likely be rain from most south of I 84 because they’re simply isn’t enough cold air around.

[anthonymm]

12 hours ago, SnoSki14 said:

You aren't getting snow in the city next week. High is retreating, low will cut west. Not enough cold out ahead of it either. 

It's a lost cause

C-1" ---> rain. Good for the ski resorts in NY and southern VT though! They need snow.

[sussexcountyobs]

State salt trucks are filled and sitting along rt. 23 in Sussex county. Guess they're expecting some lake effect snow showers this afternoon. They learned their lesson a couple weeks ago. Lol

[MJO812]

32 minutes ago, Krs4Lfe said:

That’s the real killer here because if there was more sea ice, then it definitely would’ve been colder and northern Canada, which bleeds down to the rest of Canada and is the source region for the Northeast’s cold air. With such a low arctic sea ice, it limits the amount of cold air that can be tapped into in the northeast and that ends up screwing over locations along the coast until climatology becomes cold enough later in December and January. That’s just one of the many reasons why Tuesday’s storm will likely be rain from most south of I 84 because they’re simply isn’t enough cold air around.

Its also early December.  Be patient , the cold is coming.

[eduggs]

This is the kind of storm that I can imagine looking borderline for snow right down to the Bronx until the NAM sends the vortmax to Buffalo and torches 900mb to 8C... signaling the rest of guidance to rain to Albany.

That said, synoptically, right now as modeled, it's pretty close for snow even in the City itself. The ICON and GFS have shifted slightly colder/south at 12z and 6z respectively, and ensembles (if you believe they are useful at this range) are south of their parent operational runs. The antecedent cold is marginally supportive. It wouldn't take a huge change in the shortwave structure aloft to lead to a snowier outcome further south.

It's not what I would bet on, but there is still some reasonable chance... especially outside of concrete jungles.

[qg_omega]

3 hours ago, MJO812 said:

That timeframe should be watched.

That’s a brutal phase 8 response

[MJO812]

6 minutes ago, qg_omega said:

That’s a brutal phase 8 response 

Yep break out the shorts 

 

[Cobalt]

23 minutes ago, qg_omega said:

That’s a brutal phase 8 response

As opposed to the brutal 4-5-6 response from last year?

On 9/28/2024 at 12:27 PM, qg_omega said:

4-5-6 all winter

 

On 8/18/2024 at 12:31 PM, qg_omega said:

+4 to +8 DJF early call

 

On 8/18/2024 at 12:30 PM, qg_omega said:

No reason to not go warmest winter ever, Nina + -PDO = 4+5+6 all winter

 

On 8/16/2024 at 9:43 PM, qg_omega said:

Warmest winter ever looks increasingly likely