Winter 2024-25 Discussion/Speculation

[Stormchaserchuck1]

In January-February-March, the October NAO actually has a pretty good opposite correlation with the NAO of those months.. it's about 45%. This is impressive because no other months of the year have a correlation <50%. 

Default of these maps is positive, so it's showing after a + index state

I know this -NAO is falling into the realm of September, but just barely.. because it's the last few days of the month, it probably has a 49% correlation to the Winter NAO (since Oct is 45% and Sept is 51%).  

[Terpeast]

For a week in a row, CFS has shows February, not December to be the best winter month. Skeptical because it goes against the nina grain and what we’ve seen in the last several winters. Precip pattern shows a coastal track, too.

Not particularly putting any weight on this, just not much more than a “hmm” moment.

 

[psuhoffman]

On 9/15/2024 at 6:45 AM, CAPE said:

The more poleward Aleutian ridge is the most important feature for our area in a Nina. That along with the stretched/southward displaced TPV idea the climate models have been hinting at would provide a mechanism for cold air delivery at times. During colder periods the thermal boundary could push over/just to the south of us. Models have also been hinting at possible HL blocking. Fwiw the advertised h5 look on the latest CFS runs look quite acceptable for Jan, and Feb too.

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

[SnowenOutThere]

2 hours ago, psuhoffman said:

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

It's ok, I'm sure the dastardly underwater volcanoes causing that will calm down soon. 

[Maestrobjwa]

5 hours ago, Terpeast said:

For a week in a row, CFS has shows February, not December to be the best winter month. Skeptical because it goes against the nina grain and what we’ve seen in the last several winters. Precip pattern shows a coastal track, too.

Not particularly putting any weight on this, just not much more than a “hmm” moment.

 

That's when you know it's wrong--ain't no February the best month in a nina, lolol Man this has the be the easiest winter to forecast ever! Don't even have to go to school to do it 

[Terpeast]

22 minutes ago, Maestrobjwa said:

That's when you know it's wrong--ain't no February the best month in a nina, lolol Man this has the be the easiest winter to forecast ever! Don't even have to go to school to do it 

Well, we thought a cold and active february was a lock even the last week of jan this year. Models were showing it for months. Then it slipped away at the last minute.

You never know. 

[CAPE]

5 hours ago, psuhoffman said:

Your micro analysis is correct. But on the macro we live at a location that needs a decent negative departure to get snow and consistently for years every projection shows 80% of the hemisphere red. 

I have learned to largely ignore the colors on the super LR tools and follow the height lines, focusing instead on the flow around/between upper level features. That look should bring some cold southward. Ofc it's a single panel attempting to depict the general longwave pattern for an entire month. 

[GaWx]

6 minutes ago, CAPE said:

I have learned to largely ignore the colors on the super LR tools and follow the height lines, focusing instead on the flow around/between upper level features. That look should bring some cold southward. Ofc it's a single panel attempting to depict the general longwave pattern for an entire month. 

But don’t forget that the mean H5 shown on this and other long range models could easily be wrong. Last winter is just one example. If H5 had even been close, last winter would have been much better. They’ve overall averaged too cold in recent years in the E US.

[CAPE]

4 minutes ago, GaWx said:

But the mean H5 shown on this and other long range models could easily be wrong. Last winter is just one example. If H5 had even been close, last winter would have been much better. They’ve overall averaged too cold in recent years in the E US.

Certainly could be. These tools have proven to be variable and quite limited, and thus the 'Fwiw' disclaimer when I post them.

[psuhoffman]

On 9/17/2024 at 4:46 PM, CAPE said:

I have learned to largely ignore the colors on the super LR tools and follow the height lines, focusing instead on the flow around/between upper level features. That look should bring some cold southward. Ofc it's a single panel attempting to depict the general longwave pattern for an entire month. 

Sorry if I didn’t articulate it well. I agreed with your analysis of that prog.  It wasn’t awful, about as good as we could expect in a Nina. I’d take it. 
 

I was making a 30,000 ft view comment not specific to that plot.  And yea in theory the flow should matter more. Unless it’s just warm all over which has actually been the case too often. 
 

This has been the reality the last 9 years.  

and our snow had been what you would expect in those temps!  Sure we could get lucky and someday we get a cycle where the pattern puts that little tiny blue dot that’s over BC over us instead. But the probabilities of that when 90% of the hemisphere has seasonal temp anomalies that wouldn’t support a snowy winter here isn’t very good regardless of the pattern. 
 

Just for reminders this is what a snowy winter looks like. The last 5 above normal snowfall winters at BWI

That’s what snowy looks like.  It’s been a long arse time since we saw those kind of seasonal negative anomalies anywhere in the mid latitudes.  But that’s what we need!  
 

Now this doesn’t mean we can’t get any snow. And I’ll be tracking as always looking for that fluke that might happen on an otherwise hostile regime. I’ve recalibrated.  But I doubt if we can get a seasonal anomaly that looks like our “snowy winters” one with current SST profiles no matter what the specific long wave pattern details are. We’re rooting for one off fluke events imo. 

[dallen7908]

  If anyone is bored, there is a storm to track along the Brooks Range ...  
From the weather discussion, it looks like the NAM is the outlier. 


"Snow will be moving into the area Friday
  morning and continue through Sunday morning before tapering off
  to light snow and flurries. The snow may be heavy at times,
  including along the Dalton Highway. Temperatures will be chilly,
  with highs in the 20s and low 30s as well as lows in the teens." 

 

[chris21]

On 9/18/2024 at 9:35 PM, psuhoffman said:

Sorry if I didn’t articulate it well. I agreed with your analysis of that prog.  It wasn’t awful, about as good as we could expect in a Nina. I’d take it. 
 

I was making a 30,000 ft view comment not specific to that plot.  And yea in theory the flow should matter more. Unless it’s just warm all over which has actually been the case too often. 
 

This has been the reality the last 9 years.  

and our snow had been what you would expect in those temps!  Sure we could get lucky and someday we get a cycle where the pattern puts that little tiny blue dot that’s over BC over us instead. But the probabilities of that when 90% of the hemisphere has seasonal temp anomalies that wouldn’t support a snowy winter here isn’t very good regardless of the pattern. 
 

Just for reminders this is what a snowy winter looks like. The last 5 above normal snowfall winters at BWI

That’s what snowy looks like.  It’s been a long arse time since we saw those kind of seasonal negative anomalies anywhere in the mid latitudes.  But that’s what we need!  
 

Now this doesn’t mean we can’t get any snow. And I’ll be tracking as always looking for that fluke that might happen on an otherwise hostile regime. I’ve recalibrated.  But I doubt if we can get a seasonal anomaly that looks like our “snowy winters” one with current SST profiles no matter what the specific long wave pattern details are. We’re rooting for one off fluke events imo. 

One of the reasons I moved to a location 4000 feet high a mile from Roan Mountain, TN. Upslope snow is about the only guarantee these days.

[CAPE]

 

[Ji]

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He seems bullish on winter

[CAPE]

4 hours ago, Ji said:

He seems bullish on winter

Agrees with the CFS for Jan and Feb.

[psuhoffman]

5 hours ago, Ji said:

He seems bullish on winter

That pattern is better than 2020 or 2023. It’s not a total snowless dud type pattern. But it’s not a snowy pattern either. It’s likely something like 2018/2021/2022. Maybe in the new normal that is snowy lol. 

[Maestrobjwa]

4 hours ago, psuhoffman said:

That pattern is better than 2020 or 2023. It’s not a total snowless dud type pattern. But it’s not a snowy pattern either. It’s likely something like 2018/2021/2022. Maybe in the new normal that is snowy lol. 

Perhaps we oughta name it the scenery snow pattern 

[CAPE]

12 hours ago, psuhoffman said:

That pattern is better than 2020 or 2023. It’s not a total snowless dud type pattern. But it’s not a snowy pattern either. It’s likely something like 2018/2021/2022. Maybe in the new normal that is snowy lol. 

This is what I'm thinking. Remains to be seen if a Nino with relatively warm air in Canada can give us the above normal snowfall seasons anymore. Need a Modoki with legit -AO/NAO in the next few years.

[Bob Chill]

Intuition is telling me this winter will be OK. We've been on a multi year stretch of stale cold. Always slower and shallower than first anticipated. Setups have been half decent at times but I can't count how many times mid level flow had already turned sw too far in advance before a shortwave arrives. It feels like if all shortwaves arrived just 12-18 hours sooner than they actually did (like models often showed in the mid range lol), stats would look a lot better. Not great but not in the gutter either. Subtle variances in lw trough alignment can always mess with us and we've been getting our asses handed to us. WDI index is high to win a few even if thru dumb luck 

Before 2015 got rolling in Feb, we failed in similar ways quite a bit. Once the lw trough axis shifted things heated up. 2015 isn't an analog in any way to me. Just using it as an example of failing with stale cold or mid levels scouring top early. 

My total wag is this winter will have several condensed periods that feel like real winter. Periods of -epo/+pna make a lot of sense to me like the climate models are starting to think about now. 

Counter-intuitive surprises are probably here to stay in any enso IMHO. Good luck guessing that right year after year if it keeps happening lol. Volatility is baking in it seems lol

We had some see-saw winters sandwiched between the big nino years of 02-03/09-10. My wag is a mix of that stuff. Haven't thought much about it. We'll see how it goes 

 

[Round Hill WX]

Weatherbell's winter forecast...seems reasonable given the indices. 

A Look at Winter (weatherbell.com)

[GramaxRefugee]

1 hour ago, Round Hill WX said:

Weatherbell's winter forecast...seems reasonable given the indices. 

A Look at Winter (weatherbell.com)

Seems like a lot more on the MJO than I recall previous years.

 

[frd]

Central and Eastern Canada to get a little closer to normal if true 

 

 

[40/70 Benchmark]

On 9/24/2024 at 1:21 PM, Bob Chill said:

Intuition is telling me this winter will be OK. We've been on a multi year stretch of stale cold. Always slower and shallower than first anticipated. Setups have been half decent at times but I can't count how many times mid level flow had already turned sw too far in advance before a shortwave arrives. It feels like if all shortwaves arrived just 12-18 hours sooner than they actually did (like models often showed in the mid range lol), stats would look a lot better. Not great but not in the gutter either. Subtle variances in lw trough alignment can always mess with us and we've been getting our asses handed to us. WDI index is high to win a few even if thru dumb luck 

Before 2015 got rolling in Feb, we failed in similar ways quite a bit. Once the lw trough axis shifted things heated up. 2015 isn't an analog in any way to me. Just using it as an example of failing with stale cold or mid levels scouring top early. 

My total wag is this winter will have several condensed periods that feel like real winter. Periods of -epo/+pna make a lot of sense to me like the climate models are starting to think about now. 

Counter-intuitive surprises are probably here to stay in any enso IMHO. Good luck guessing that right year after year if it keeps happening lol. Volatility is baking in it seems lol

We had some see-saw winters sandwiched between the big nino years of 02-03/09-10. My wag is a mix of that stuff. Haven't thought much about it. We'll see how it goes 

 

Yes. This is what I have been arguing...that pattern hasn't been great, but we have also had bad luck in that the timing has consistently been poor.

[psuhoffman]

On 10/2/2024 at 11:21 AM, 40/70 Benchmark said:

Yes. This is what I have been arguing...that pattern hasn't been great, but we have also had bad luck in that the timing has consistently been poor.

I don't know about the bad luck part.  Sure we've had opportunities that didn't work out...but I don't feel like the fail rate has been higher than is typical.  What if some of the few snow events we did get had NOT worked out!  

Numerically I think we've had about what we should expect from the status quo longwave pattern of the last 8 years.  I say that because there have been 2 comparable historical periods with a very similar predominant longwave pattern.  The 1950s and 1970s.  And while the current snowfall results have been worse than both, they have only been about 15-20% worse depending on the location and that is what several regression studies indicate can be expected due to warming since those two periods.  So IMO our snowfall results have been what they should be if you factor in the pattern and adjust expectations down from past similar periods due to the warmer climate. 

 

See below, if you adjust for the colder climo of the 1950's and 1970s...the current ass pattern matches pretty closely with the ass patterns of those two prior periods, and the results when adjusted for warming are exactly what should be expected. 

Past Ass

Current Ass

Until this current pac dominant pattern breaks we probably shouldn't expect much deviation from what we've experience since 2016.   In our specific location that is below normal snowfall...with the only debate being how much below.  

 

[40/70 Benchmark]

3 hours ago, psuhoffman said:

I don't know about the bad luck part.  Sure we've had opportunities that didn't work out...but I don't feel like the fail rate has been higher than is typical.  What if some of the few snow events we did get had NOT worked out!  

Numerically I think we've had about what we should expect from the status quo longwave pattern of the last 8 years.  I say that because there have been 2 comparable historical periods with a very similar predominant longwave pattern.  The 1950s and 1970s.  And while the current snowfall results have been worse than both, they have only been about 15-20% worse depending on the location and that is what several regression studies indicate can be expected due to warming since those two periods.  So IMO our snowfall results have been what they should be if you factor in the pattern and adjust expectations down from past similar periods due to the warmer climate. 

 

See below, if you adjust for the colder climo of the 1950's and 1970s...the current ass pattern matches pretty closely with the ass patterns of those two prior periods, and the results when adjusted for warming are exactly what should be expected. 

Past Ass

Current Ass

Until this current pac dominant pattern breaks we probably shouldn't expect much deviation from what we've experience since 2016.   In our specific location that is below normal snowfall...with the only debate being how much below.  

 

It has up here...perhaps not down there...but that is how it goes. Everything went right last decade, so it evens out. 

[psuhoffman]

32 minutes ago, 40/70 Benchmark said:

It has up here...perhaps not down there...but that is how it goes. Everything went right last decade, so it evens out. 

Except from 2000-2020 while north of us was setting records left and right we were actually slightly below avg (old averages anyways) for the period. Our snow climo was already degrading even during the favorable pattern we were in during that period. 

[JenkinsJinkies]

47 minutes ago, psuhoffman said:

Except from 2000-2020 while north of us was setting records left and right we were actually slightly below avg (old averages anyways) for the period. Our snow climo was already degrading even during the favorable pattern we were in during that period. 

I wonder if 2003, 2009/10, and 2016 masked that to the untrained observer?

[psuhoffman]

3 hours ago, JenkinsJinkies said:

I wonder if 2003, 2009/10, and 2016 masked that to the untrained observer?

I believe so. Precipitation events are also increasing so when we do get a rare snowy year they can be big.  Not only is our mean and median dropping but variance is increasing. From 1996 to 2016 we were getting more 10”+ snowstorms even while getting less snow overall!  We were getting some of our snowiest winters while getting less snow overall. The big red flag to me was that places that used to be correlated to our snow decoupled. NYC started getting a lot of above avg snow seasons while we were below. There started to be a very sharp cutoff just to our north. Kinda like used to happen just to our south!  I mean even in a snowy winter at some point you’re just too far south for it to matter. IMO that line was shifting north on average.  
 

Because we use current averages as a baseline it masks this some because we’ve already lost a significant % of our snow climo. I think this is the best way to illustrate it. 
 

From 1996-2016 the mean pattern was this!

look at that. Over 21 years that was the average base pattern. 
 

But at DCA only 6 years of the 21 were above avg snow! And this was the averages at the 3 reporting stations

DCA: 15.9” IAD: 23.7”. BWI: 22.9”

Now if we compare that to what’s happened since that looks like snow Valhalla. But the 30 year mean at all 3 airports going into that period was 18.5”, 23.6” and 22.3” 

The mean avg across all 3 stations going into 1996 was 21.5” but from 1996 to 2016 with the best possible long term cycle we could hope for the seasonal avg was 20.9”.  The mean avg snowfall across the area was actually slightly less during those 21 years than the 30 years before despite being what should have been a very snowy period which was very snowy…just to our north!  
 

I think the “you’re too far south for the pattern to matter” line has been shifting north for a while and even once the pattern gets better there is a chance on some years it’s still to our north. 
 

 

 

[Eskimo Joe]

Just give me climo snowfall with -1 temps for the seasonal and I'll consider it a win.

[Terpeast]

52 minutes ago, Eskimo Joe said:

Just give me climo snowfall with +2 temps for the seasonal and I'll consider it a win.

Fixed