January 2019 General Discussion & Observations

[North and West]

1 hour ago, dWave said:

Yeah I grew up so envious of those living "north & west." 3" events in the city was enough to make me happy back then. That what I grew up under so like most things, ppl use there formative years as the baseline for the rest of their life. All these big snow events on a regular basis in the 2000s has been a dream come true, but I never got confortable with it. I feel it can end any time lol. 

Bingo. And I am North and West... but not enough. When I was a kid, it felt like truly it was only Sussex County Specials. 

[the_other_guy]

1 hour ago, EastonSN+ said:

On the flip side, 4 inches fell in Nov. 1995 and it was the snowiest winter ever.

4 inches fell Nov. 2002 and it was the 2nd snowiest winter.

6 inches fell 2012 and my area ended above average while NYC reached average.

So for every 1989, 2011 there are the above cases. Basically early snow has no affect on winter.

Your posting Nov snowfall history without context.

 

Look at the third week in November. If it falls after that that usually leads to an above normal season.

 

If it falls before that it almost ALWAYS leads to a well below normal season.

 

There have only been a couple of instances where the above scenario has led to above normal seasonal snowfall...And they were both well below normal snowfall winters except for one big storm. In one case...they waited til March.

 

We don’t have much iron clad history in wx, And what we do have seems to be getting shattered in a new climate. But this statistic is pretty hard.

[Brian5671]

4 minutes ago, jfklganyc said:

Your posting Nov snowfall history without context.

 

Look at the third week in November. If it falls after that that usually leads to an above normal season.

 

If it falls before that it almost ALWAYS leads to a well below normal season.

 

There have only been a couple of instances where the above scenario has led to above normal seasonal snowfall...And they were both well below normal snowfall winters except for one big storm. In one case...they waited til March.

 

We don’t have much iron clad history in wx, And what we do have seems to be getting shattered in a new climate. But this statistic is pretty hard.

Yeah, I think the takeaway is that October or early Nov snow is not good-late November works...

[snowheavyattimes]

51 minutes ago, Brian5671 said:

Yeah, I think the takeaway is that October or early Nov snow is not good-late November works...

Yes but what is the scientific explanation for early season snow = lack of later season snow. That’s the question I have.

[redbanknjandbigbasslakepa]

We need a big cutter to flip this pattern and get some higher heights in the NAO region. Looks like we’ll get that next weekend with a big rainstorm. I think between 1/25-2/1 we could see a somewhat more favorable pattern. Until then no snow in NYC aside of a flurry or shower. 

[TJW014]

75 miles north and east, and I'll be happy.

[the_other_guy]

17 minutes ago, redbanknjandbigbasslakepa said:

We need a big cutter to flip this pattern and get some higher heights in the NAO region. Looks like we’ll get that next weekend with a big rainstorm. I think between 1/25-2/1 we could see a somewhat more favorable pattern. Until then no snow in NYC aside of a flurry or shower. 

I believe this theory was also floated in early January with a cutter. 

 

Not saying you are wrong, but another poster said 1/20 is our “next chance” after this weekend suppressed.

 

 

[NEG NAO]

24 minutes ago, redbanknjandbigbasslakepa said:

We need a big cutter to flip this pattern and get some higher heights in the NAO region. Looks like we’ll get that next weekend with a big rainstorm. I think between 1/25-2/1 we could see a somewhat more favorable pattern. Until then no snow in NYC aside of a flurry or shower. 

This look like a big rainstorm cutter next weekend ? Not that I trust the American models during the shutdown BUT going forward the -AO + PNA pattern developing would argue against cutters for a while

[EastonSN+]

1 hour ago, jfklganyc said:

Your posting Nov snowfall history without context.

 

Look at the third week in November. If it falls after that that usually leads to an above normal season.

 

If it falls before that it almost ALWAYS leads to a well below normal season.

 

There have only been a couple of instances where the above scenario has led to above normal seasonal snowfall...And they were both well below normal snowfall winters except for one big storm. In one case...they waited til March.

 

We don’t have much iron clad history in wx, And what we do have seems to be getting shattered in a new climate. But this statistic is pretty hard.

We need a met to chime in (bluewave/Neg AO/Goose). I do not think a week or 2 difference in Nov. Timing makes that much of a difference and March is still a snowfall month like last year which was epic.

What would be the scientific explanation? 

Besides 1989 and 2011 how many other cases saw snow before the 15th of November and were below average snowfall winters?

[PB COLTS NECK NJ]

23 minutes ago, NEG NAO said:

This look like a big rainstorm cutter next weekend ? Not that I trust the American models during the shutdown BUT going forward the -AO + PNA pattern developing would argue against cutters for a while

 

The pattern flip started today  ( the 10th has been opined on in here and the source region has changed , so that looks like it will work). As I said last week the risk for this weekends system was East of us not West.

I agree with the above , that`s not cutting. The 2 dates I posted in here 7 days ago were the 13th and 20th - the 13th heads off to our S and the confluence and placement of the TPV in Canada wins out.

But that was always an option. 

We aren`t getting a big cutter and that TPV is on the move as - 50 air is showing up in E Canada in the L/R. 

We are heading into a very cold period ( colder the deeper we go ) . But a " pattern change " doesn`t mean it has to snow. BN`s have now returning and the 19 - 23 period is the next favorable period for a system in the area.

But I would caution that not every good pattern produces snow , cold and dry is always an option , however one thing is evident warm and wet are over for the time being. 

[SnowGoose69]

6 minutes ago, EastonSN+ said:

We need a met to chime in (bluewave/Neg AO/Goose). I do not think a week or 2 difference in Nov. Timing makes that much of a difference and March is still a snowfall month like last year which was epic.

What would be the scientific explanation? 

Besides 1989 and 2011 how many other cases saw snow before the 15th of November and were below average snowfall winters?

It could make a difference.  Patterns have a tendency to set in for 5-6 weeks if you look at a given location and take the patterns over say a 5 year period you’ll find many instances of them lasting 5-6 weeks.  So let’s say you set into a pattern conducive to cold and storminess 11/5.  That pattern may end 12/10 or 15 and then you’re waiting til 1/20 or so if you don’t get lucky those first 2 weeks of December.  If the cold snowy pattern sets in 11/20 and you get a snow event you may also see more snow events in mid to late December in those years as you have the whole month.  Also a negative AO/NAO pattern taking over 11/1 or 11/5 is statistically less likely to tell the story of the ensuing winter than one that takes over 11/25

[gravitylover]

13 minutes ago, EastonSN+ said:

We need a met to chime in (bluewave/Neg AO/Goose). I do not think a week or 2 difference in Nov. Timing makes that much of a difference and March is still a snowfall month like last year which was epic.

What would be the scientific explanation? 

Besides 1989 and 2011 how many other cases saw snow before the 15th of November and were below average snowfall winters?

It's tough to formulate a scientific reason when using a human construct like the calendar. It might be different if it was a lunar calendar but I expect not too much. 

[EastonSN+]

6 minutes ago, SnowGoose69 said:

It could make a difference.  Patterns have a tendency to set in for 5-6 weeks if you look at a given location and take the patterns over say a 5 year period you’ll find many instances of them lasting 5-6 weeks.  So let’s say you set into a pattern conducive to cold and storminess 11/5.  That pattern may end 12/10 or 15 and then you’re waiting til 1/20 or so if you don’t get lucky those first 2 weeks of December.  If the cold snowy pattern sets in 11/20 and you get a snow event you may also see more snow events in mid to late December in those years as you have the whole month.  Also a negative AO/NAO pattern taking over 11/1 or 11/5 is statistically less likely to tell the story of the ensuing winter than one that takes over 11/25

Cool. But still a 2 or 3 week difference should make no difference in overall winter snowfall total I.e. this year. If this pattern produces we still endured the 5 week shutout and got to or above average. If the snow happened the end of November then the good pattern would have been just delayed to beg. Of Feb. Wouldn't that be worse?

[SnowGoose69]

Just now, gravitylover said:

It's tough to formulate a scientific reason when using a human construct like the calendar. It might be different if it was a lunar calendar but I expect not too much. 

There are more complicated theories that cold too early in November or December for a long period causes atmospheric impacts with heat distribution to the poles/tropics etc.  that have a tendency to cause the back half of the winter to be milder.  We do sometimes see the same thing occur in the summer.  Years where we’ve gotten too warm too early for several weeks in late April or mid May sometimes the core of the summer is colder.  I think maybe 1987 was an example of this but I might have the wrong year 

[gravitylover]

@SnowGoose69 I've been a heat distribution theory fan for a long time so someday I'd love to hear your ideas on that stuff. Especially in early and late season cases where wavelengths are transitioning from seasonally long/short to otherwise where one storm in the hemisphere can throw a wrench in the atmospheres plans.

[RU848789]

29 minutes ago, EastonSN+ said:

We need a met to chime in (bluewave/Neg AO/Goose). I do not think a week or 2 difference in Nov. Timing makes that much of a difference and March is still a snowfall month like last year which was epic.

What would be the scientific explanation? 

Besides 1989 and 2011 how many other cases saw snow before the 15th of November and were below average snowfall winters?

We don't need a met for this discussion - this is purely a stats discussion and there aren't enough data points to be making conclusions or even correlations between many of the things being posited around here, like a big storm in Nov and snowfall outcome after that - typically one needs a few dozen data points.  The stats rule of thumb has always been that one needs 30 data points to ensure statistical significance - that truly depends on the system and the data, but it's still a decent rule of thumb, and there's no question that <10 and especially <5 data points is not statistically significant for establishing correlations.  

https://statswithcats.wordpress.com/2010/07/11/30-samples-standard-suggestion-or-superstition/

[Gravity Wave]

1 minute ago, RU848789 said:

We don't need a met for this discussion - this is purely a stats discussion and there aren't enough data points to be making conclusions or even correlations between many of the things being posited around here, like a big storm in Nov and snowfall outcome after that - typically one needs a few dozen data points.  The stats rule of thumb has always been that one needs 30 data points to ensure statistical significance - that truly depends on the system and the data, but it's still a decent rule of thumb, and there's no question that <10 and especially <5 data points is not statistically significant for establishing correlations.  

https://statswithcats.wordpress.com/2010/07/11/30-samples-standard-suggestion-or-superstition/

That's what I always come back to in these discussions. The modern age of weather analysis and forecasting hasn't been around long enough to provide sufficient data to make solid rules for every situation or circumstance.

[donsutherland1]

3 hours ago, frd said:

 Don, any idea whether you think we still see a severe drop in the AO sometime in the next few weeks?

At times is was talked about, and the various longe range modeling has blocking at top, yet when I check the CPC for the AO ensemble forecast it has been varying. Granted, negative, but not as much agreement on a big dive like there was a few days ago. 

In the background the SSWE continues and warming at the pole seems on target along with the hopeful lag effect of a -AO and eventual drop to negative with the NAO. Maybe the "steep" decline in the AO awaits a lag to hit, speculating later this month?

Just wondering your thoughts on this,  and maybe the CPC product is not the best indicator of the AO's  furture forecast.  

 

 

    

Right now, I think a drop to -3.000 is more likely than not. The SSW's impacts are slowly working through the troposphere. The polar vortex has been split. I am not sure if the recent SSW is contributing to model volatility.

Finally, today's preliminary AO value is -1.914 (the lowest so far this winter) and below where it was forecast to be on today's date (yesterday's forecast).

[RU848789]

26 minutes ago, Gravity Wave said:

That's what I always come back to in these discussions. The modern age of weather analysis and forecasting hasn't been around long enough to provide sufficient data to make solid rules for every situation or circumstance.

And even when there's a more robust data set, like for tropical season predictions, the best they're doing is maybe 60% accuracy vs. the 33% accuracy one would get from random guessing (if the choices are above average, average and below average for any parameter).  Analog-based forecasting will never be more than a semi-quantitative tool, IMHO.  

[frd]

8 minutes ago, donsutherland1 said:

Right now, I think a drop to -3.000 is more likely than not. The SSW's impacts are slowly working through the troposphere. The polar vortex has been split. I am not sure if the recent SSW is contributing to model volatility.

Finally, today's preliminary AO value is -1.914 (the lowest so far this winter) and below where it was forecast to be on today's date (yesterday's forecast).

Thanks Don, much appreciated ! 

[Gravity Wave]

1 minute ago, RU848789 said:

And even when there's a more robust data set, like for tropical season predictions, the best they're doing is maybe 60% accuracy vs. the 33% accuracy one would get from random guessing (if the choices are above average, average and below average for any parameter).  Analog-based forecasting will never be more than a semi-quantitative tool, IMHO.  

Agreed, similarities and analogs are helpful but no two patterns will ever be completely alike and as we all know tiny changes can make huge differences downstream.

[RU848789]

12Z Euro has nada north of 195/276 and only an inch down in Philly to Toms River and only 2-3" for DC/Balt.  Right now, no major global model is showing more than 1" north of 195/276, so this threat is on life support, IMO.  Hoping for mood flakes now.  

[LongBeachSurfFreak]

Welcome back 1985. I’ll take another Gloria

[MJO812]

1 hour ago, RU848789 said:

12Z Euro has nada north of 195/276 and only an inch down in Philly to Toms River and only 2-3" for DC/Balt.  Right now, no major global model is showing more than 1" north of 195/276, so this threat is on life support, IMO.  Hoping for mood flakes now.  

Ukie never showed snow up here

[MJO812]

Just now, bluewave said:

Looks like the 12z EPS is going for a gradient type pattern storm around the Jan 19-20. The exact latitude of the gradient may come down to the MJO amplitude and influence at the time.

 

Nice - epo

[NycStormChaser]

Upton and Mt Holly not in agreement through Sunday morning. 

 

[weathermedic]

8 minutes ago, NycStormChaser said:

Upton and Mt Holly not in agreement through Sunday morning. 

 

That has changed slightly (OKX)

[NycStormChaser]

4 minutes ago, weathermedic said:

That has changed slightly (OKX)

Both issues at the same time. On their website there's a map for pinpoint and a map for a range 

[weathermedic]

Either way looks over done.

[MJO812]

3 minutes ago, weathermedic said:

Either way looks over done.

They are banking on some overrunning precip with the very cold temps for ratios.

Quite possible