December 2023

[WX-PA]

1 hour ago, bluewave said:

With a little luck we can sneak in a better +PNA look like 12z instead of 6z.But we know these long range GFS OP runs always change. I think it will again come down to seeing if we can get at least a transient break from the trough out West. 
 

12z

 

6z

 

It's amazing we need luck to get snow in the northeast in January. If that's the case everybody give up your hobby folks..It's a different climate.

[STORMANLI]

1 hour ago, rclab said:

Afternoon everyone. Would it help if the weenie emoji was changed to something like this? I used it in a reply to a forky post. Stay well all, as always ….

 

And then "Frank It Up"!!?

[rclab]

1 hour ago, STORMANLI said:

And then "Frank It Up"!!?

“Ouch” as always …..

[donsutherland1]

White Christmas vs. 50° Christmas: New York City:

[bluewave]

3 hours ago, WX-PA said:

It's amazing we need luck to get snow in the northeast in January. If that's the case everybody give up your hobby folks..It's a different climate.

It seems like we need luck these days to get the Pacific to relax. The amped up Pacific Jet in recent years keeps driving troughs into the Western US. The NYC 6”+ snowstorm composite taking in 19 events since the 09-10 winter shows how important it is to get the Pacific on our side. The primary feature necessary has been a strong 500 mb ridge over the Rockies in the West. The secondary feature has been a Greenland block. 
 

NYC 6”+ snowstorm composite of the last 19 events since 09-10 

 

 

Days used:
1/31/2021
03/14/2017
12/26/2010
12/17/2020
02/09/2017
02/13/2014
02/08/2013
11/15/2018
01/22/2016
02/03/2014
01/26/2011
03/22/2018
01/26/2015
01/22/2014
02/25/2010
01/04/2018
03/05/2015
01/03/2014
12/19/2009

 

[SnowGoose69]

12 minutes ago, bluewave said:

It seems like we need luck these days to get the Pacific to relax. The amped up Pacific Jet in recent years keeps driving troughs into the Western US. The NYC 6”+ snowstorm composite taking in 14 event since the 09-10 winter snows now important it is to get the Pacific on our side. The primary feature necessary has been a strong 500 mb ridge over the Rockies out West. The secondary feature has been a Greenland block. 
 

NYC 6”+ snowstorm composite of the last 14 events since 09-10 winter.

 

It seems we no longer can get overrunning events with trofiness in the west.  Events like December 84/90 January 89/December 08 just do not happen anymore....it seems everything just wants to super amp or undergo massive phases in those good overrunning type setups so you just get way too much mid level torching vs long duration overrunning to start.   Many people mention how the coastal low track like January 87 has sort of vanished which is why people in CNY/CPA have struggled somewhat the last 10-15 years but the weaker/moderate SWFE seems to have sort of vanished too

[Dark Star]

5 hours ago, forkyfork said:

you should have to explain the hypsometric equation to be able to post

Is that what the kids are calling it these days?

[donsutherland1]

Parts of the Northeast saw their coldest temperatures so far this season. Low temperatures included:

Boston: 21°
Bridgeport: 20°
Islip: 24°
New Haven: 22°
New York City: 25°
Newark: 25°
Philadelphia: 29°
Poughkeepsie: 17°
White Plains: 20°

The cold will now move out of the region after its latest short stay. Afterward, generally warmer than normal conditions will likely prevail through most of the remainder of December.

A transition to a colder pattern could commence during the first week of January. Severe cold appears unlikely early in the transition. There remains uncertainty concerning the magnitude and duration of the colder period that could develop. At this time, it appears more likely than not that it will be seasonably cold or somewhat colder than normal with a duration of 1-2 weeks.

The ENSO Region 1+2 anomaly was +1.5°C and the Region 3.4 anomaly was +2.0°C for the week centered around December 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.85°C and the ENSO Region 3.4 anomaly has averaged +1.95°C. A basinwide El Niño event is ongoing. El Niño conditions may strengthen somewhat further this month.  

The SOI was -30.67 today.

The preliminary Arctic Oscillation (AO) was +1.941 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. Therefore, blocking will likely return in January, if historic experience is representative. The latest GEFS shows a return to Atlantic blocking.

On December 20 the MJO was in Phase 7 at an amplitude of 0.834 (RMM). The December 19-adjusted amplitude was 0.818 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 43.5° (4.4° above normal). That would make December 2023 the 6th warmest December on record.

 

[LibertyBell]

51 minutes ago, bluewave said:

It seems like we need luck these days to get the Pacific to relax. The amped up Pacific Jet in recent years keeps driving troughs into the Western US. The NYC 6”+ snowstorm composite taking in 19 events since the 09-10 winter shows how important it is to get the Pacific on our side. The primary feature necessary has been a strong 500 mb ridge over the Rockies in the West. The secondary feature has been a Greenland block. 
 

NYC 6”+ snowstorm composite of the last 19 events since 09-10 

 

 

Days used:
1/31/2021
03/14/2017
12/26/2010
12/17/2020
02/09/2017
02/13/2014
02/08/2013
11/15/2018
01/22/2016
02/03/2014
01/26/2011
03/22/2018
01/26/2015
01/22/2014
02/25/2010
01/04/2018
03/05/2015
01/03/2014
12/19/2009

 

Is this why it snows so much more in Japan at the same latitude? They are also on the western fringe of an ocean but they don't have to deal with the eastern Pacific.

North America is unfortunately a puny continent compared to Eurasia, I wonder how much more snow we would have if there was no Pacific Ocean influence to mess things up (in other words if North America was the size of Eurasia.)

 

[LibertyBell]

43 minutes ago, SnowGoose69 said:

It seems we no longer can get overrunning events with trofiness in the west.  Events like December 84/90 January 89/December 08 just do not happen anymore....it seems everything just wants to super amp or undergo massive phases in those good overrunning type setups so you just get way too much mid level torching vs long duration overrunning to start.   Many people mention how the coastal low track like January 87 has sort of vanished which is why people in CNY/CPA have struggled somewhat the last 10-15 years but the weaker/moderate SWFE seems to have sort of vanished too

no more bowling bowl type systems or super clippers -- they all go north of us

we get the super weak 1-2 inch ones (at best), no more moderate snowfalls of 3-5 or 4-6 inches and even 6-8 inch snowfalls are rare (just like moderate snowfall winters are), it's either a small 1-2 inch snowfall or 10"+ lol

The last system of the type I'm thinking of was in late February 2008 when we got a surprise 6-8" in a very mild pattern.

[Volcanic Winter]

What would 1/29/22 be classified as? That had a phase IIRC right? I feel like had that storm cut NW like 40-50 miles it would be remembered as a top tier event. Was so close to something special, and was an extremely fun (and nail biting) storm to track on here. 

[MJO812]

I miss bombing clippers

[eduggs]

6 hours ago, bluewave said:

With a little luck we can sneak in a better +PNA look like 12z instead of 6z.But we know these long range GFS OP runs always change. I think it will again come down to seeing if we can get at least a transient break from the trough out West. 
 

Ensembles have a transient relaxation of the western trof next weekend. 500mb anomaly charts look decent around that time too. Unfortunately the actual surface weather is likely to be rain to dry NW flow. That's the weakness of 500mb height anomaly charts. Favorable anomalies are only loosely correlated to local snowfall. Snow threat identification requires a closer examination of the full synoptic evolution, not just 500mb and not just a snapshot in time. 500mb anomaly charts are also better suited for identifying setups that won't deliver as opposed to ones that will.

[eduggs]

1 hour ago, bluewave said:

It seems like we need luck these days to get the Pacific to relax. The amped up Pacific Jet in recent years keeps driving troughs into the Western US. The NYC 6”+ snowstorm composite taking in 19 events since the 09-10 winter shows how important it is to get the Pacific on our side. The primary feature necessary has been a strong 500 mb ridge over the Rockies in the West. The secondary feature has been a Greenland block. 
 

NYC 6”+ snowstorm composite of the last 19 events since 09-10 

 

 

As you mention, certain key features are correlated to NYC snowfall, particularly if you isolate major snowstorms. So this is a situation where the features are necessary but not sufficient. That's part of the frustration with long range forecasting. Even if we see these features modeled, we usually don't get a snowstorm. The other major issue for the LR is that ensemble modeling is not stable or reliable enough beyond 10 days to make accurate regional forecasts.

[bluewave]

15 minutes ago, eduggs said:

Ensembles have a transient relaxation of the western trof next weekend. 500mb anomaly charts look decent around that time too. Unfortunately the actual surface weather is likely to be rain to dry NW flow. That's the weakness of 500mb height anomaly charts. Favorable anomalies are only loosely correlated to local snowfall. Snow threat identification requires a closer examination of the full synoptic evolution, not just 500mb and not just a snapshot in time. 500mb anomaly charts are also better suited for identifying setups that won't deliver as opposed to ones that will.

It was implied in my post since I just figured everyone realized that it had to be cold enough for that pattern to produce a 6”+ snowstorm in NYC. We get that pattern plenty of times when it is too warm for snow. So it’s necessary but not sufficient if cold air is lacking. Plus there are many times when some aspect of that pattern present when it’s cold enough but lesser amounts of snow occur. 

[snowman19]

Ensembles have a transient relaxation of the western trof next weekend. 500mb anomaly charts look decent around that time too. Unfortunately the actual surface weather is likely to be rain to dry NW flow. That's the weakness of 500mb height anomaly charts. Favorable anomalies are only loosely correlated to local snowfall. Snow threat identification requires a closer examination of the full synoptic evolution, not just 500mb and not just a snapshot in time. 500mb anomaly charts are also better suited for identifying setups that won't deliver as opposed to ones that will.

The early January cool down is fitting the “script” of past strong/super Nino events to a tee. There is very good evidence (forcing) that come mid-late January we go RNA and it gets mild again. The big question is February. If this one continues as past events have, that will be the wintry month of the winter. Wait and see time now. So far the timeline is fitting perfectly ever since late November. 


See this:

[eduggs]

4 minutes ago, bluewave said:

It was implied in my post since I just figured everyone realized that it had to be cold enough for tat pattern to produce a 6”+ snowstorm in NYC. We get that pattern plenty of times when it is too warm for snow. So it’s necessary but not sufficient if cold air is lacking.

Are you suggesting that "cold" is independent from "pattern?" That doesn't make a lot of sense to me. You might as well just wait until "cold" and "moisture" are collocated at the same time and place before forecasting snow. 

A so called favorable "pattern" is never sufficient for snow around here.

[bluewave]

5 minutes ago, eduggs said:

Are you suggesting that "cold" is independent from "pattern?" That doesn't make a lot of sense to me. You might as well just wait until "cold" and "moisture" are collocated at the same time and place before forecasting snow. 

A so called favorable "pattern" is never sufficient for snow around here.

Sometimes it is when the source regions are devoid of cold enough air as was the case on 12–05-20.

[eduggs]

6 minutes ago, snowman19 said:

The early January cool down is fitting the “script” of past strong/super Nino events to a tee. There is very good evidence (forcing) that come mid-late January we go RNA and it gets mild again. The big question is February. If this one continues as past events have, that will be the wintry month of the winter. Wait and see time now. So far the timeline is fitting perfectly ever since late November. 


See this: https://www.twitter.com/webberweather/status/1737967733260882329?s=46&t=NChJQK9_PUjA1K7D2SMojw

IMO the coupled global atmosphere and ocean systems are way too complex for easily identifiable and repeatable patterns. Personally I think there are general recurrent features, but not as predicable as you suggest. "El Nino" is a numerical range used to represent a particular geophysical variable in a general region. No two El Nino seasons are even close to being the same.

[bluewave]

3 minutes ago, eduggs said:

IMO the coupled global atmosphere and ocean systems are way too complex for easily identifiable and repeatable patterns. Personally I think there are general recurrent features, but not as predicable as you suggest. "El Nino" is a numerical range used to represent a particular geophysical variable in a general region. No two El Nino seasons are even close to being the same.

Complexity is just an excuse for the inability to see the greater underlying repeating patterns throughout nature which includes weather forecasting. 

[eduggs]

4 minutes ago, bluewave said:

Sometimes it is when the source regions are devoid of cold enough air as was the case on 12–05-20.

What you posted is not a "pattern." It's a graphical representation of a set of numerical values at the continental-scale. It's a purely static depiction. Any meaningful definition of weather "pattern" should incorporate the wave dynamics associated with evolution and propagation of airmasses. In that way, "pattern" and "cold" should always be interrelated.

In fairness, everyone on this forum would be better off if we all stopped using the term "pattern" because it usually just leads to misunderstandings and unfulfilled expectations.

[bluewave]

8 minutes ago, eduggs said:

What you posted is not a "pattern." It's a graphical representation of a set of numerical values at the continental-scale. It's a purely static depiction. Any meaningful definition of weather "pattern" should incorporate the wave dynamics associated with evolution and propagation of airmasses. In that way, "pattern" and "cold" should always be interrelated.

In fairness, everyone on this forum would be better off if we all stopped using the term "pattern" because it usually just leads to misunderstandings and unfulfilled expectations.

Then you haven’t been following this thread recently since the wave dynamics leading to these patterns have been spoken about repeatedly. 

Most people on this forum know that a pattern which produces snow is contingent on cold air. We know that the pattern I outlined which produces the benchmark storm track needs cold air for snow.

 

 

[eduggs]

6 minutes ago, bluewave said:

Complexity is just an excuse for the inability to see the greater underlying repeating patterns throughout nature which includes weather forecasting. 

I'll say it another way.

The physical and psychological attributes that make a good basketball player are complex. If we relied only on simplistic metrics like height to predict basketball prowess, we would not be very successful basketball scouts. 

The forecasting of complex patterns requires very precise identification of causal factors and large practice-set sample sizes, both of which are currently lacking in LR weather forecasting.

[eduggs]

3 minutes ago, bluewave said:

Then you haven’t been following this thread recently since the wave dynamics leading to these patterns have been spoken about repeatedly. 

Most people on this forum know that a pattern which produces snow is contingent on cold air. We know that the pattern I outlined which produces the benchmark storm track needs cold air. 

 

 

I have been following intently, for years. I appreciate you enthusiasm a lot. I think your concept of "pattern" is on shaky ground. I also don't think the current state of LR forecasting allows you or anyone else to identify productive snow periods more than about 10 days in advance.

I would respectfully encourage you and everyone else to follow Walt's lead and focus more of specific synoptic feature combinations in the mid-range and less of fleeting fantasy "patterns" out in fantasy land.

[bluewave]

7 minutes ago, eduggs said:

I'll say it another way.

The physical and psychological attributes that make a good basketball player are complex. If we relied only on simplistic metrics like height to predict basketball prowess, we would not be very successful basketball scouts. 

The forecasting of complex patterns requires very precise identification of causal factors and large practice-set sample sizes, both of which are currently lacking in LR weather forecasting.

Scouts can be overrated if you ever saw the movie Moneyball. 

The patterns only appear complex if you are missing the lowest common denominator or underlying reality. 
 

[eduggs]

16 minutes ago, bluewave said:

Then you haven’t been following this thread recently since the wave dynamics leading to these patterns have been spoken about repeatedly. 

Most people on this forum know that a pattern which produces snow is contingent on cold air. We know that the pattern I outlined which produces the benchmark storm track needs cold air for snow.

 

By the way, the reason why next weekend fails to deliver is not because of lack of cold. It's because the modeled PVA is either too far offshore of fails to fully round the base of the northern stream trof to initiate surface low formation close enough to our region to produce precipitation.

The difference between snow and no snow is in those fine-scale synoptic details and their evolution in time. Snapshot anomaly charts and "pattern" recognition just can't capture those details.

[bluewave]

Just now, eduggs said:

By the way, the reason why next weekend fails to deliver is not because of lack of cold. It's because the modeled PVA is either too far offshore of fails to fully round the base of the northern stream trof to initiate surface low formation close enough to our region to produce precipitation.

The difference between snow and no snow is in those fine-scale synoptic details and their evolution in time. Snapshot anomaly charts and "pattern" recognition just can't capture those details.

We were discussing a nearly 384 hr GFS OP very low skill hypothetical which changes every 6 hours to pass the time since people have been so bummed out about a lack of snow. Just read back a few pages to see the many challenges the actual pattern will have to produce snow. These continuing challenges through December were outlined here starting back in the late fall. So we were outlining changes which would probably need to happen in order for NYC to break its 1 and 2 inch record long losing streaks. 

[North and West]

White Christmas vs. 50° Christmas: New York City:

.

[MJO812]

Can we just enjoy the fact that the models are actually showing a pattern change and it's gaining traction. 

 

[North and West]

Is that what the kids are calling it these days?

I have been watching TWC my whole life and my closest, lifelong friends are meteorologists… and I’ve never heard them mention that before.


.