December 2022

[EasternLI]

5 minutes ago, EastonSN+ said:

AO region is completely different. PV was over Canada. We do have a neg AO though so could be very interesting.

Took a little exotic maneuvering, but we're making progress again. 

[kat5hurricane]

6 minutes ago, Brian5671 said:

13/14 too...although March was bone dry which stunk.   

It was an amazing back to back winter stretch. '14-'15 was a lot more moderate snowstorms but we had sustained snowpack for over a month with pack refreshers every couple of days seemingly. A thing of beauty for snowpack hounds such as myself.

[lee59]

1 hour ago, MJO812 said:

We don't need arctic air for snow

Pattern looks much better next week 

I agree, as we get deeper into winter we don't necessarily need arctic air. However the coldest of the air has for some time now been out west and then goes east mostly to our south. As of now the pattern does not seem to be changing much, we are just getting naturally chillier and this could be good enough for inland areas.

[Roger Smith]

Odd isn't it that Feb 15 was close to all-time record cold for winter months and then Dec 15 was the opposite, followed by a top class snowstorm in Jan 16, 

Here's a factoid for Don and other climate buffs, locally it was the coldest November since 1985. Seems to be evolving into a similar December for us, it remained rather cold but came up almost to the December normal value. I don't know if 1985-86 is much of a winter analogue in your area, I recall what it was like in Ontario, very cold around Christmas 85 then a lot of rather boring near-average weather without a lot of snow for that region. A very warm March followed.

[Stormlover74]

58 minutes ago, lee59 said:

I agree, as we get deeper into winter we don't necessarily need arctic air. However the coldest of the air has for some time now been out west and then goes east mostly to our south. As of now the pattern does not seem to be changing much, we are just getting naturally chillier and this could be good enough for inland areas.

The gfs gets quite chilly in about 10 days 

[Brian5671]

21 minutes ago, Stormlover74 said:

The gfs gets quite chilly in about 10 days 

always 10 days....

[MJO812]

12 minutes ago, Brian5671 said:

always 10 days....

No but every model has the change 

[EasternLI]

It's not a happy PV on guidance I'm seeing either. It's still up and running, but doing so with 2 black eyes and a broken arm at the end of most runs. Not only that, but increasingly. Definitely interested. 

[CIK62]

Snow still a Bust Sunday PM-Monday PM:                      EURO/CMC have slight chance of 1".           On to the 18th?

For its full run we get this measly % for an inch, mostly from 17-18 and 23.      Seems to be warming for Christmas anyway.

 

[wdrag]

Anyway, for Sunday 4P-Monday 4A, most of the 1-5" acc in the nw-ne sector thread but some modeling trying to bring 1/2" to NYC including the 18z/8 EC via Pivotal.  

[EasternLI]

Look at the tilt through the vertical column. That is not good, bordering on terrible for the vortex. It's been having a bad year with no signs of stopping. 

[donsutherland1]

Cooler air is now overspreading the region. Tomorrow through the weekend will likely see highs in the lower and middle 40s. A system could bring some rain or perhaps wet snow to parts of the region Sunday night into Monday. Some areas could see a light accumulation of snow.

With the development of an EPO-/AO-/PNA- pattern following a short-lived rebound in the EPO to positive levels, colder air intrusions could again become more frequent toward mid-December. The potential for snowfall could also begin to increase, as well, as a sustained colder pattern begins to develop, but significant snowfall is not likely during the transition to that colder pattern. No severe cold is likely through at least the first three weeks of December. The latest EPS weeklies suggest that near normal to below normal temperatures could prevail during the December 19-26 period.

The latest guidance suggests that the AO could fall to -3.000 or below during the second week of December. Since 1950, there were 24 cases that saw the AO reach -3.000 or below during December. Mean snowfall for those cases was 6.2" (Median: 6.0"). 50% of such cases saw December wind up with 6.0" or more snow (25% saw 10.0" or more). In contrast, during all other December cases, mean December snowfall was 3.5" (Median: 2.5"). In those cases, 21% of years saw December snowfall of 6.0" or more while 8% saw 10.0" or more snowfall.

The ENSO Region 1+2 anomaly was -0.5°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 30. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.42°C and the ENSO Region 3.4 anomaly has averaged -0.95°C. La Niña conditions will likely persist through mid-winter.

The SOI was +5.92 today.

The preliminary Arctic Oscillation (AO) was -3.372 today.

On December 6 the MJO was in Phase 3 at an amplitude of 0.995 (RMM). The December 5-adjusted amplitude was 0.867 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 51% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 39.2° (0.1° above normal).

 

[EasternLI]

[bkviking]

1 hour ago, EasternLI said:

Please say clearly your thoughts 

[Stormlover74]

It's the nam but colder and showing some snow monday morning

[eduggs]

The (18z) GFS soundings are torched, NAM is cold AF, and the Canadian is in between. One scenario is a non-event outside the elevated interior, and the other is an advisory snowfall including slush covered roads to the City's near suburbs.

The surface low position initially near Lake Erie historically suggests a warm outcome. And synoptically I keep expecting the meat of this event to shift into NY and western NE. But there is a pretty potent pocket of vorticity with steep lapse rates, an unusual angle of approach, and relatively cold surface air is nearby. There's is also a mesoscale banded feature at the tail end that may or may not mean anything.

This is an interesting event to track It would be great for this to move in early and provide some rare weekend, daytime snowflakes.

[eduggs]

That was a helpful nudge south, colder, and a hair stronger on the 0z GFS. The boundary layer temps are still on the higher end of guidance, but it gets snow to the hills a little bit closer to the City.

[MJO812]

Next weekends storm trended more favorable 

Earlier secondary with the primary further south. Great hit for the interior .

[SnoSki14]

4 minutes ago, MJO812 said:

Next weekends storm trended more favorable 

Earlier secondary with the primary further south. Great hit for the interior .

I think that could be our snowstorm 

[MJO812]

1 minute ago, SnoSki14 said:

I think that could be our snowstorm 

Courtesy of the Mid Atlantic 

 

[eduggs]

Don't try to catch a falling knife. Still lots of run to run changes and this is 7+ days out. This look for the late week storm next week is MUCH better than the mega cutter from a few days ago, but we should wait to see how it shakes out over the next few days before mentally investing too heavily.

We have 2 trackable winter events over the next 10 days! Not bad after a long warm season.

[brooklynwx99]

oops!

[Newman]

There's some pretty big solutions showing up on the GEFS, especially for the interior but even some for the coast

[Volcanic Winter]

26 minutes ago, eduggs said:

we should wait…

before mentally investing too heavily.

Too late, I’m all in. Choo choo baby. Hear that? Hype train is right on schedule. 

[mattinpa]

39 minutes ago, Newman said:

There's some pretty big solutions showing up on the GEFS, especially for the interior but even some for the coast

I’ll take Ensemble member 20

[Tatamy]

4 hours ago, mattinpa said:

I’ll take Ensemble member 20

The CMC is going with rain on the coast and ice inland for the event later next week.  The Euro is rain for most with ice well inland for this one.  The GFS seems to be on it’s own with the big snows.

[EasternLI]

7 hours ago, bkviking said:

Please say clearly your thoughts 

I'm increasingly thinking we're heading right for the -AO winter scenario. The vortex is in rough shape. Certainly not strengthening rapidly like it should be at this time of year. In addition, the tropical looks are starting to resemble phase 6, if not phase 7. That's according to both gefs and eps this morning at the end of those runs. This would also be a very bad development for the vortex. Precursors have also displayed themselves this season already. The Urals blocking is an example of that. There's signs pointing towards this outcome, and we haven't deviated from that path. If anything, we're further along that path in my eyes. 

[Tatamy]

06z GFS is an HECS.  This one would produce blizzard conditions and hurricane force winds in the offshore waters.  Big stuff on this run of the GFS.

[Tatamy]

21 minutes ago, Tatamy said:

The CMC is going with rain on the coast and ice inland for the event later next week.  The Euro is rain for most with ice well inland for this one.  The GFS seems to be on its own with the big snows.

FWIW the 0z ensembles of the CMC are markedly colder than the OP in terms of precip type for the event later next week- especially inland.

[MJO812]

Gfs continues to trend further south with both the primary and the secondary