Jan Medium/Long Range Disco: Winter is coming

[Kevin Reilly]

53 minutes ago, snowfan said:

No, not bad. But the surface….verbatim….is meh for now. Emphasis on for now. 

I am thinking the first step to a better pattern is to get rid of the damm cut off low that moved west over the mid-west and is now beginning to move east. 

[Kevin Reilly]

5 minutes ago, IronTy said:

JB just posted about how the upcoming period has the most severe cold potential of any period he's seen in years.  Finally some good news that you can take to the bank, guaranteed.  

JB just posted about how the upcoming period has the most severe cold potential of any period he's seen in years.  Every year as we come out of Christmas like we are all looking for some dam late presents or something!

[osfan24]

1 hour ago, stormy said:

The historic Jan. 66 blast didn't begin until Jan. 22.    During the next 2 weeks we had nearly 40 inches of snow.  Everybody needs to settle down and be patient!

My post was not to say the winter is a bust. We could most certainly shuffle the deck in mid-January and then go on a run in our true prime climo. I was only talking about this upcoming window from early to mid January.

[Ralph Wiggum]

1 hour ago, stormy said:

The historic Jan. 66 blast didn't begin until Jan. 22.    During the next 2 weeks we had nearly 40 inches of snow.  Everybody needs to settle down and be patient!

This!! Majority of pro forecasters here and elsewhere have repeated ad nauseum that the expectation this was always IF we are going to see a legit wintry deep pattern that would not happen until 2nd or 3rd week of January thru late Feb. It's hard to believe but it is possible still. I ha e very minimal accums up here but I'm not far west of the fall line and have seen flakes 5 times already. So yes. It CAN snow still. And yes. It WILL snow again. Patience.

[osfan24]

14 minutes ago, IronTy said:

JB just posted about how the upcoming period has the most severe cold potential of any period he's seen in years.  Finally some good news that you can take to the bank, guaranteed.  

Even if he was right, which he probably wasn't, those of us looking for snow and big snow at that do not want severe cold. Congrats Atlanta!

[Ralph Wiggum]

1 hour ago, Ji said:

you cant have a epic winter if you get no snow from Dec to Mid January. YOu can have epic storm or epic month but i think the epic winter stuff now is not likely to happen

Bro, lower your expectations. Epic winter are rare for a reason.

[RIC_WX]

1 hour ago, stormy said:

The historic Jan. 66 blast didn't begin until Jan. 22.    During the next 2 weeks we had nearly 40 inches of snow.  Everybody needs to settle down and be patient!

Being conscious of my tone, we should probably be very cautious when referencing analogs from what was objectively the coldest decade of the entire 20th century and attempting to apply them to modern times.  

[eduggs]

1 hour ago, CAPE said:

For those who look at the 18z GFS and think it is a crap run verbatim (Hi Ji), remember it is a single op run and we are still 8 + days out from the initial window of interest. Look at the big picture at h5- the shortwaves are on the playing field, rolling across the southern US, while the HL look is favorable(note the oranges/ reds in the right places). We just can't know the details yet.

 

Everything depends on the evolution and orientation of the height fields. Individual shortwave interactions make or break regional weather outcomes. The 10 days 12z GFS vs CMC charts illustrate that. The colors (anomalies) being in the "right" places can't tell us much beyond 10 days. Even worse if the height anomalies are time-averaged in addition to being ensemble-averaged. That degree of smoothing completely masks the critical details. By the time those "colors" are usefully predictive, the mid range models can already start working out finer-scale details including shortwave interactions.

Looking for periods where the LR anomalies are favorable is completely backwards IMO. It mistakenly assumes an unknown future "flow state" can have a causal impact on a future weather outcome. The reality is that height anomalies and future regional weather are correlated but NOT sequentially causally connected. They only appear to be that way in hindsight and when performing reanalysis. Years of poor performance of this forecasting strategy should have encouraged a shift towards the Walt Drag method. But people see what they want to see. They crave understanding if they don't have control. And they squint to see a light at the end of a dark tunnel.

[eduggs]

January is always the most likely month of the year for cold and snow in the Mid-Atlantic coastal plain, regardless of the state of climate indices. So predicting that there will be cold periods in January and maybe some snow is not a bold call. But there is also reason to be concerned that this historically bad stretch of winters might be systemic. The tendency for ULLs to tilt and deepen west of us over the mid-continent but flatten and dampen to our east could be somehow related to a changing climate. Our already too-small-sample size of seasonal analogs may be increasingly useless as we move forward in time. The possibility that this winter could be another ratter is a legitimate concern. All we can reasonably see out into the weather future is about 10 days, and this upcoming period has at least as much potential as any so far this winter. But no, I do not agree that patience is warranted. There is less time left in winter than it would seem.

[CAPE]

12 minutes ago, eduggs said:

Everything depends on the evolution and orientation of the height fields. Individual shortwave interactions make or break regional weather outcomes. The 10 days 12z GFS vs CMC charts illustrate that. The colors (anomalies) being in the "right" places can't tell us much beyond 10 days. Even worse if the height anomalies are time-averaged in addition to being ensemble-averaged. That degree of smoothing completely masks the critical details. By the time those "colors" are usefully predictive, the mid range models can already start working out finer-scale details including shortwave interactions.

Looking for periods where the LR anomalies are favorable is completely backwards IMO. It mistakenly assumes an unknown future "flow state" can have a causal impact on a future weather outcome. The reality is that height anomalies and future regional weather are correlated but NOT sequentially causally connected. They only appear to be that way in hindsight and when performing reanalysis. Years of poor performance of this forecasting strategy should have encouraged a shift towards the Walt Drag method. But people see what they want to see. They crave understanding if they don't have control. And they squint to see a light at the end of a dark tunnel.

Damn dude, you've had way more than me.

[Ji]

Damn dude, you've had way more than me.

Go google that

[CAPE]

3 minutes ago, Ji said:

Go google that

gib·ber·ish

Gibberish, also called jibber-jabber or gobbledygook, is speech that is nonsense: ranging across speech sounds that are not actual words, pseudowords, language games and specialized jargon that seems nonsensical to outsiders.

[87storms]

I’ll say this. 
I’m not canceling winter and as long as we’re in a nino, I’ll never cancel it. Even if it means ‘winter’ will only be a one and done 18”+ storm. 
However, I think if we get to Jan 1 and guidance shows nothing of note through the 15th, it will at that point be safe to say that a 2009-10 or 2002-03 blockbuster is definitely off the table.
We may get a 2014-15 or 65-66 style ending, though. So at that point, I’ll probably downgrade my outlook to 15-30” instead of 20-40” areawide (not including my DCA siting penalty). We can easily get 15-30” in one storm.
ofc I’ll grade my outlook based on my original forecast, so it’s probably not going to earn an A. 

I’m not even focusing on a good winter at this point lol…getting a 1-3” clipper would be an upgrade over the last 2 years. I agree with your general thesis, though…aka it’s too early to throw in the towel.

[jayyy]

gib·ber·ish
Gibberish, also called jibber-jabber or gobbledygook, is speech that is nonsense: ranging across speech sounds that are not actual words, pseudowords, language games and specialized jargon that seems nonsensical to outsiders.

Truly dumbfounded by a lot of the things I read on here. Makes me appreciate folks like yourself even more. Keep doing you man. Love the positivity you have and sticking to pure analysis (minus the emotions many others inject into their “forecasts”.

Some folks either a) live in the wrong CWA and/or need a new hobby if their expectations are wall to wall winter in the Mid-Atlantic. It’d be one thing if we lived in New Hampshire… but Maryland Delaware and Virginia?! Come on. If “epic” winters were commonplace, they wouldn’t be epic.

It’s becoming increasingly intolerable to scroll through these threads, so I just wanna shout you out for being one of the more consistent and level headed posters in here.

[87storms]

…I should have said 1.5 years, since early to mid Jan 2022 did produce.

[KChuck]

43 minutes ago, eduggs said:

All we can reasonably see out into the weather future is about 10 days

10 days you say? I'd be happy if we'd be able to hit 5 days out on snow events! 

[nj2va]

1 hour ago, eduggs said:

Everything depends on the evolution and orientation of the height fields. Individual shortwave interactions make or break regional weather outcomes. The 10 days 12z GFS vs CMC charts illustrate that. The colors (anomalies) being in the "right" places can't tell us much beyond 10 days. Even worse if the height anomalies are time-averaged in addition to being ensemble-averaged. That degree of smoothing completely masks the critical details. By the time those "colors" are usefully predictive, the mid range models can already start working out finer-scale details including shortwave interactions.

Looking for periods where the LR anomalies are favorable is completely backwards IMO. It mistakenly assumes an unknown future "flow state" can have a causal impact on a future weather outcome. The reality is that height anomalies and future regional weather are correlated but NOT sequentially causally connected. They only appear to be that way in hindsight and when performing reanalysis. Years of poor performance of this forecasting strategy should have encouraged a shift towards the Walt Drag method. But people see what they want to see. They crave understanding if they don't have control. And they squint to see a light at the end of a dark tunnel.

Is this what happens when chat gpt tries to interpret weather models?

[WinterFire]

https://x.com/webberweather/status/1740164865161924685?s=46
 

Fwiw even Webb isn’t canceling winter (and tbh he’s been more bullish on this winter than he’s given credit for, he just likes to troll the snow weenies on Twitter)

[psuhoffman]

2 hours ago, eduggs said:

Everything depends on the evolution and orientation of the height fields. Individual shortwave interactions make or break regional weather outcomes. The 10 days 12z GFS vs CMC charts illustrate that. The colors (anomalies) being in the "right" places can't tell us much beyond 10 days. Even worse if the height anomalies are time-averaged in addition to being ensemble-averaged. That degree of smoothing completely masks the critical details. By the time those "colors" are usefully predictive, the mid range models can already start working out finer-scale details including shortwave interactions.

Looking for periods where the LR anomalies are favorable is completely backwards IMO. It mistakenly assumes an unknown future "flow state" can have a causal impact on a future weather outcome. The reality is that height anomalies and future regional weather are correlated but NOT sequentially causally connected. They only appear to be that way in hindsight and when performing reanalysis. Years of poor performance of this forecasting strategy should have encouraged a shift towards the Walt Drag method. But people see what they want to see. They crave understanding if they don't have control. And they squint to see a light at the end of a dark tunnel.

Beyond about day 7 and definitely day 10 we don’t have the skill to examine details and specific threats. The best we can do is identify the long wave pattern and what our chances to get a specific threat might be in that case pattern. 

[Ji]

Gl low!



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[NorthArlington101]

Gl low!



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Well the 00z GFS goes for the “what storm?” approach which might be preferable

[Ji]

Well the 00z GFS goes for the “what storm?” approach which might be preferable

Gfs also lost that silly Jan 2-3 coastal that had no support

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[Ji]

Cmc looks like it may deliver

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[WEATHER53]

6 hours ago, Terpeast said:

Did anyone notice the 12z euro? I know it’s the op run, but look

Cold high up top, gulf low brewing. It’s a miss, but it’s close. 

This is the look for DC snowstorms. Low might be south but not in OV. 

[WEATHER53]

5 hours ago, Ji said:

its one random run of the OP but nobody thought they would see a map like this on Jan 8

I knew and said the delays need to stop by 1/10

correctiin to 1/10

[Ji]

This is the look for DC snowstorms. Low might be south but not in OV. 

According to wxrisk.com the 18z was more north

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[Ji]

I knew and said the delays need to stop by 1/19!

Here you go. Pattern change as advertised!


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[WEATHER53]

1 minute ago, Ji said:

According to wxrisk.com the 18z was more north

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I’m happy to see something nice and be able to comment accordingly .

How is Da**d T. these days?

 

[eduggs]

23 minutes ago, psuhoffman said:

Beyond about day 7 and definitely day 10 we don’t have the skill to examine details and specific threats. The best we can do is identify the long wave pattern and what our chances to get a specific threat might be in that case pattern. 

I think you've hit on why it has a poor track record in terms of assessing storm threats in the LR. There are a couple problems:

1. "Longwave pattern" is a very general concept. It's continental-scale - meaning correlations with regional weather are weak - particularly in a predictive sense. Yes significant snow is well correlated to characteristic "patterns," but since there are far more of these "patterns" than significant snowstorms, we know that these features are necessary but not sufficient for big snowfall.

2. Significant uncertainty exists in ensemble modeling forecasts beyond 10 days. Even if aspects of a 500mb height field are well predicted over parts of the globe, other areas are poorly predicted. It's usually not possible to know which regions will be well modeled. This keeps overall confidence in LR pattern recognition relatively low.

3. The sub-continental scale details only resolvable inside 10 days largely determine whether a global scale longwave pattern can be productive for regional wintry precipitation or not. This would be true even if you knew the precise longwave pattern in advance.

Add these up and the argument is that using low confidence LR anomaly charts to try to identify general "patterns" is not very effective for LR regional storm threat identification. At the very same time you are able to start determining if a nearing "pattern" is a head-fake or not you are just starting to pick out the finer scale mid-and upper level details. Some of the same models are used for both objectives (pattern ID and details), and they both start to clarify at the far end of the mid-range simultaneously. That's why I believe multi-model ensemble QPF and 850mb temperature charts inside 10 days are the better starting point for threat identification. Followed by looping the raw 500mb heights with vorticity of both the ensembles and operational models inside about 8 days.

It's funny how people are so quick to come up with excuses for why a sure-fire pattern change advertised on the models failed to materialize. It's usually something random like a bridging ridge, west or east-based something, one of the indices... AO, EPA, NAO offset ENSO. What those excuses are really a reflection of is that modeled LR "patterns" are not causally connected to future outcomes. One does not cause the other. They are both simultaneous reflections of the state of the atmosphere-ocean system at a given time.

[Ji]

I’m happy to see something nice and be able to comment accordingly .
How is Da**d T. these days?
 

I think he still hates us

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