December 2024

[Brian5671]

3 minutes ago, NEG NAO said:

chances are one will be correct...maybe both......

OP models for day 10...nuff said

[Allsnow]

Dr. No says no 

[MJO812]

Just now, Allsnow said:

Dr. No says no 

Better than previous runs but we know this model isn't like it use to be. 

[North and West]

Huge changes run to run.  They are really struggling with this pattern.

I wonder which one will be real.



.

[NEG NAO]

15 minutes ago, MJO812 said:

Better than previous runs but we know this model isn't like it use to be. 

yes especially when its not the solution we want to see,,,,,,,

[bluewave]

33 minutes ago, brooklynwx99 said:

I don't see that at all... there's strong HP over the top as the coastal takes shape. this looks like snow or bust with the evolution on the 12z GFS / CMC

The 12Z Euro is even more northern stream dominant with  stronger low in the Great Lakes.

[MJO812]

Just now, bluewave said:

The 12Z Euro is even more northern stream dominant with  stronger low in the Great Lakes.

It now develops a coastal offshore which is a positive .

[bluewave]

9 minutes ago, MJO812 said:

It now develops a coastal offshore which is a positive .

The coastal could be too suppressed. But even a northward correction in later runs would be an issue along the coast with the low in the Great Lakes instead of a cold high.Very difficult to pull off a good thread the needle along the coast with such a fast northern stream Pacific flow.

[MJO812]

27 minutes ago, bluewave said:

The coastal could be too suppressed. But even a northward correction in later runs would be an issue along the coast with the low in the Great Lakes instead of a cold high.Very difficult to pull off a good thread the needle along the coast with such a fast northern stream Pacific flow.

Timing and it has happened.  Thread the needle.

[Yanksfan]

So we go from a Canadian clipper that never enters the US to suppression depression in 12 hours. Gotta love the GFS.

[donsutherland1]

In terms of snowfall over the next 10-14 days, the GGEM might offer a reasonable good case scenario for the immediate NYC area. IMO, trying to envision a significant or major storm ignores the reality of the forecast pattern. Interior sections continue to have the best chance of seeing a moderate snowfall. Some changes to the forecast pattern are still possible, but really substantial changes would be needed for there to be a blockbuster storm.

Consider how many times big maps are posted on Social Media. Only a small number actually verify. Posting aggressive maps while ignoring the overall forecasting environment sets one up for a high probability of failure.

[MJO812]

1 hour ago, bluewave said:

The 12Z Euro is even more northern stream dominant with  stronger low in the Great Lakes.

Eps looks better than op. The AI version also.

[bluewave]

44 minutes ago, MJO812 said:

Timing and it has happened.  Thread the needle.

It’s more about the northern stream being too dominant than timing. We were better off last February with the borderline super El Niño. At least some spots were able to go over 10” on the season due to the STJ being able to dominate over the northern stream for about a week. 

[Allsnow]

8 minutes ago, bluewave said:

It’s more about the northern stream being too dominant than timing. We were better off last February with the borderline super El Niño. At least some spots were able to go over 10” on the season due to the STJ being able to dominate over the northern stream for about a week. 

Great snow band here that month…

[mgerb]

6 hours ago, wdrag said:

Thanks Matt,  never really sure where all the NY Subforum posters are located... I tend to start at I78 north.. but understand south of I78 as you pointed out in the stats.  I am concerned the drought monitor is not nearly responsive enough (flashy trends both ways).  

One thing I'll mention about your last point is this week's DM map was valid through 12Z 12/10, before the ~2" fell in northern NJ, thus wasn't accounted for in the decision to leave things status-quo in the 12/12 map. I'd expect next week's map should show some improvement up north (esp northwest of I 287 in NJ); less sure about areas further south, where precip over the last week has been around or slightly above normal, but not enough to support much improvement. At least it appears that we'll continue seeing regular precip events to keep things from degrading further, but the hope obviously is to have some above-normal months this winter/spring to help prepare for the warmth/demand of the spring and summer. 

[NorthShoreWx]

4 hours ago, psv88 said:

22 last night. North wind stayed up on the north shore so we didn’t really radiate. Areas further south away from the sound radiated better and had less influence from the sounds warm waters. Rarely happens but it does happen occasionally. 

We only made it down to 25 here as the wind stayed up all night.  Looks like today's max is going to be 32.  It's backed off to 31 now.

[SACRUS]

As we march towards the winter solstice and continue to lose daylight (from later sunrises), the sunset is a minute later from the 4:28 PM low and is now 4:29.  

 

[Snowlover11]

WWA here sunday night into monday.

[Wxoutlooksblog]

33 minutes ago, Snowlover11 said:

WWA here sunday night into monday.

In the NYC Metro Region I do not think anything will accumulate if there is even any wet snow at all (which I doubt). The one threat I have noted several times that kept hope alive this month was for Dec 21-22nd. Right now IMO it doesn't look likely to come to fruition. But we'll see. Other than that unlikely threat, I see no accumulating snow threats for the NYC Metro Region for at least the next 2 weeks.

WX/PT

[lee59]

After a high of 36, already down to 30. Maybe another night in the teens.

[donsutherland1]

Today was another cold day. The cold will last through the weekend before milder air returns early next week. It could then turn unseasonably mild for a time. Additional rain is possible early next week. Following the rain, it will again turn somewhat colder before a much sharper shot of cold arrives for during or after the next weekend. The potential exists for the temperature to fall into the teens for the first time this season in New York City.

Beyond that, the pattern will likely remain changeable through much of the rest of the month on account of a fast jet stream.  The overall anomaly for the final week of the month is unusually uncertain with most of the ensemble guidance and the weekly guidance in disagreement. However, the probability of a mild end to the month and mild start for the first few days of January has increased.

In recent days, an occasional run of the operational GFS showed a significant snowstorm from Washington, DC to New York City. However, the pattern makes such an event very unlikely for this region. Since 1950, there were 5 December snowstorms that brought 6" or more snow to all three of these cities. Four (80%) occurred with a PNA+/NAO- pattern. The NAO is forecast to be positive. In addition, three (60%) occurred when the MJO was in Phase 8, which is not likely over the next 10 days. Only the December 23-25, 1966 event produced 6" or more snow in all three cities with a positive NAO, but the AO was strongly negative (< -2.000), which is not likely during the next 10 days. In sum, the interior sections will be far more favored for an appreciable or perhaps greater snowfall than the Washington-Baltimore-Philadelphia-New York City area over the next 10 days. A smaller snowfall is plausible.

The NAO fell to a preliminary -2.751 on September 24th (all-time September record: -2.371, September 12, 1971). That was the 9th lowest value on record. La Niña winters following September cases where the NAO fell to -1.900 or below featured a predominantly positive NAO. The most recent such winters were 2016-2017 and 2022-2023. The mean temperatures for those winters in New York City were 39.3° and 41.0° respectively. The 1991-2020 normal value is 36.2°. A warmer to much warmer than normal outcome is favored by the November run of the ECMWF for Winter 2024-2025.

The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was -0.3°C for the week centered around December 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged -0.20°C. Neutral ENSO conditions may still evolve into a La Niña event during the winter. Uncertainty as to whether a La Niña will actually develop continues to increase. Currently, 47% of dynamical models and 22% of the statistical models forecast the development of a La Niña.

The SOI was +3.32 today.

The preliminary Arctic Oscillation (AO) was +0.817 today.

Based on sensitivity analysis applied to the latest guidance, there is an implied 78% probability that New York City will have a colder than normal December (1991-2020 normal). December will likely finish with a mean temperature near 37.2° (1.9° below normal).

 

[SnowGoose69]

One thing is for sure, all ensembles today finally show a pattern beyond D12 that resembles the first 7 days of December more or less, albeit slightly better as ridge isn't displaced as far east.  The question is does it even last til 1/15 before everything pulls back to a La Nina type pattern.  I think the La Nina being nearly non existent helps somewhat

[STORMANLI]

20° am low

I recorded a high barometric pressure of 30.96" today.

This is the 2nd highest reading since Valentine's Day 1981 when it reached 31.05".

[snowman19]

4 hours ago, Allsnow said:

Dr. No says no 

So does Dr. 18z GFS

[snowman19]

1 hour ago, Wxoutlooksblog said:

In the NYC Metro Region I do not think anything will accumulate if there is even any wet snow at all (which I doubt). The one threat I have noted several times that kept hope alive this month was for Dec 21-22nd. Right now IMO it doesn't look likely to come to fruition. But we'll see. Other than that unlikely threat, I see no accumulating snow threats for the NYC Metro Region for at least the next 2 weeks.

WX/PT

Even up this way in Rockland I doubt any snow at all accumulates tomorrow night. That WWA is more for the glazing/freezing rain threat. And agree about next Saturday. Color me very, very skeptical of any meaningful snow event

[MJO812]

49 minutes ago, snowman19 said:

So does Dr. 18z GFS

Check the gefs

[psv88]

33 today. 

[jm1220]

31 minutes ago, psv88 said:

33 today. 

And down to 23 now. We’ll radiate a lot better tonight if winds stay calm. 

[HeadInTheClouds]

Made it down to 12 last night, 20 right now after a high of 34. Looking like around an inch Sunday night. I'll take anything right now. 1.5 inches so far this season. 

[WestBabylonWeather]

Not terribly concerned with the far range models that are always wrong

 

winter is here.