Potential extensive winter event, I-95 west and with again a chance for NYC first inch(es) of snow Mon or more likely Tue Jan 16, 2024 (serves as OBS thread as well)

[wdrag]

1 hour ago, bluewave said:

I agree with Walt that the Euro is probably too suppressed. We have seen these issues pop up since one of the upgrades around 2014 or 2015. The Euro had a great run with East Coast storm tracks from Sandy to Nemo. But something changed around 2014 or 2015. It’s either over amped at times like Jan 2015 or suppressed like Feb 2021. Plus there have been other suppression examples where the model suddenly corrects NW in the short term to match the consensus. That being said, the GEM and UKMET are pretty amped up at this range. So my concern at this point is more later runs ticking NW and presenting warmer solutions along the immediate coast than an outright suppression scenario. But we will see since there is no rush to get the exact track of this one correct until the big cutter goes by to our north tomorrow. 

Recent years suppression case

 

I still stay with the idea of a snow event inland and coastal rain/snow mix... BUT... we need to see the EC-EPS start shifting west by tomorrow morning. Right now it's trend through the 06z/12 cycle is weaker and weaker. 

 

If the Euro scored... that would be huge.  I'll be working today so you'll know how things are trending sooner than I.  

There could be a radical sudden EC-EPS shift in the next cycle 12z/12 or 00z/13 as I recall last Dec that took a snowstorm away from us by shifting to a CHICAG) storm. You may recall?  

IF no EC west shift,  then I would think the GGEM/GFS would trend noticeably east.  

I just have to wait it out. I can't be sure if its superior EC initial analysis per Roger comment earlier in this thread or something else?

[Tatamy]

9 minutes ago, cleetussnow said:

Ima save this post.  

Snowman19 is entitled to his opinions however there are other posters here whom I pay more attention to.  It doesn’t hurt to have someone with his point of view on the board.  He does substantiate his posts however a lot of that seems to be cut and paste pieces from selected posters on X.  

[wdrag]

I think one thing I important in all of our/my comments...  willingness to acknowledge the unknown-uncertainty. 

[wdrag]

Just now, Tatamy said:

Snowman19 is entitled to his opinions however there are other posters here whom I pay more attention to.  It doesn’t hurt to have someone with his point of view on the board.  He does substantiate his posts however a lot of that seems to be cut and paste pieces from selected posters on X.  

If that's true... another reason to not post on X or any other platform where your impressions are swept away to not be checked-evaluated. 

Here... you're out there to be post examined. That is valuable for others to consider whether you have anything consistently reliable to contribute. 

[pstar3182]

Exactly - outside 48 hours this forum is cosplay and wish-casting peppered in with in-depth analysis from extremely talented hobbyist to pro-mets.  Don't lose site of the uncertainty. 

[jdj5211]

06Z GFS was a nice hit for the area.  Won't be heavy snow but showed a solid 18 hour storm....easily can pick up 4-8 inches in that setup.

[brooklynwx99]

i don’t think that AK vort is the whole reason. the CMC has the same feature and amps up just fine. i think the ECMWF just struggles consolidating the trough itself 

[Typhoon Tip]

36 minutes ago, wdrag said:

I still stay with the idea of a snow event inland and coastal rain/snow mix... BUT... we need to see the EC-EPS start shifting west by tomorrow morning. Right now it's trend through the 06z/12 cycle is weaker and weaker. 

 

If the Euro scored... that would be huge.  I'll be working today so you'll know how things are trending sooner than I.  

There could be a radical sudden EC-EPS shift in the next cycle 12z/12 or 00z/13 as I recall last Dec that took a snowstorm away from us by shifting to a CHICAG) storm. You may recall?  

IF no EC west shift,  then I would think the GGEM/GFS would trend noticeably east.  

I just have to wait it out. I can't be sure if its superior EC initial analysis per Roger comment earlier in this thread or something else?

This entire handling discrepancy between guidance systems strikes me as data ingest problems.

I've posted this over in the NE thread - but the source/orgin for this event is not arriving via canonical Pacific routing but is actually an inject from SPV decay over the NW Terriorties/eastern EPO domain.  It's not abundantly clear that is either well sampled, or even natively handled ( physically..) in the guidance given that processing headache ...

1

2

3

[NJwx85]

20 minutes ago, Typhoon Tip said:

This entire handling discrepancy between guidance systems strikes me as data ingest problems.

I've posted this over in the NE thread - but the source/orgin for this event is not arriving via canonical Pacific routing but is actually an inject from SPV decay over the NW Terriorties/eastern EPO domain.  It's not abundantly clear that is either well sampled, or even natively handled ( physically..) in the guidance given that processing headache ...

1

2

3

Tip, I think the Southern stream vort that will be coming into the Pacific Northwest late tomorrow night continues to be the key player. This piece shown below on the GFS is well timed and eventually becomes part of the storm over the deep South. 

[NEG NAO]

3 minutes ago, NJwx85 said:

Tip, I think the Southern stream vort that will be coming into the Pacific Northwest late tomorrow night continues to be the key player. This piece shown below on the GFS is well timed and eventually becomes part of the storm over the deep South. 

<blockquote class="imgur-embed-pub" lang="en" data-id="a/H0jELlp" data-context="false" ><a href="//imgur.com/a/H0jELlp"></a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

in other words the old GIGO theory

In computer science, garbage in, garbage out (GIGO) is the concept that flawed, or nonsense (garbage) input data produces nonsense output. Rubbish in, rubbish out (RIRO) is an alternate wording. The principle applies to all logical argumentation: soundness implies validity, but validity does not imply soundness.

[NJwx85]

2 minutes ago, NEG NAO said:

in other words the old GIGO theory

In computer science, garbage in, garbage out (GIGO) is the concept that flawed, or nonsense (garbage) input data produces nonsense output. Rubbish in, rubbish out (RIRO) is an alternate wording. The principle applies to all logical argumentation: soundness implies validity, but validity does not imply soundness.

The animated image I was trying to embed in the post wouldn't work for some reason. I don't know what I am doing wrong. I always used to be able to embed directly from Imugr. 

In any event, I think the key player is that Southern vort. It will be coming into Oregon tomorrow. If that piece doesn't phase with the incoming trough due to poor timing the system will be either weak or too far offshore. The Euro seems to want to shear it out so there's that too.

[Typhoon Tip]

22 minutes ago, NJwx85 said:

Tip, I think the Southern stream vort that will be coming into the Pacific Northwest late tomorrow night continues to be the key player. This piece shown below on the GFS is well timed and eventually becomes part of the storm over the deep South. 

Yeaaah... I'm not gonna say 'unlikely' from this vantage, but ... that feature, albeit important in general, appears to be handled similarly between the GEFs and EPS... It's running out ahead and dematerializing in the compression gauntlet over the SE. 

(that analysis can and probably should be refined further, however)

However, the N/stream additional S/W power at mid (500 mb) level  72hours diving S out of western Canada in the GFS that the Euro doesn't have - sort of resembles an 'intermediate jet stream' feature.  

The GFS phases ... which leads to more power getting relayed E than the Euro, which doesn't perform this phenomenon because it doesn't "see" that middle stream mechanical influence.

Here...

I just didn't want to get too detailed in the previous post .. but all this is ultimately coming from the complex handling over the EPO domain. What is actually going to get sent down river determines what's tumbling over the dam

[WIN]

1 hour ago, jdj5211 said:

06Z GFS was a nice hit for the area.  Won't be heavy snow but showed a solid 18 hour storm....easily can pick up 4-8 inches in that setup.

It's funny how perspectives have changed over the last 20 years or so. In the 80s and most of the 90s, 4 to 8 was considered a heavy snowstorm.

[SBUWX23]

1 minute ago, WIN said:

It's funny how perspectives have changed over the last 20 years or so. In the 80s and most of the 90s, 4 to 8 was considered a heavy snowstorm.

I was thinking this the other day. We have been fortunate with some of the historic events in the last 10 or so years. 

[NJwx85]

3 minutes ago, Typhoon Tip said:

Yeaaah... I'm not gonna say 'unlikely' from this vantage, but ... that feature, albeit important in general, appears to be handled similarly between the GEFs and EPS... It's running out ahead and dematerializing in the compression gauntlet over the SE. 

(that analysis can and probably should be refined further, however)

However, the N/stream additional S/W power at mid (500 mb) level  72hours diving S out of western Canada in the GFS that the Euro doesn't have - sort of resembles an 'intermediate jet stream' feature.  

The GFS phases ... which leads to more power getting relayed E than the Euro, which doesn't perform this phenomenon because it doesn't "see" that middle stream mechanical influence.

Here...

I just didn't want to get too detailed in the previous post .. but all this is ultimately coming from the complex handling over the EPO domain. What is actually going to get send down river determines what's tumbling over the dam

Here is the 06z GFS, you can see that initial piece phasing in which amplifies the trough.

 

The 00z Euro shears the piece out and you're left with a positively tilted trough.

[Typhoon Tip]

9 minutes ago, NJwx85 said:

Here is the 06z GFS, you can see that initial piece phasing in which amplifies the trough.

 

The 00z Euro shears the piece out and you're left with a positively tilted trough.

Yeah, it's straight-up a wave addition or not addition taking place between the GFS vs Euro respectively. 

Not sure why the EPO relay is different - that's what I was after in describing the original bifurcation stuff. There's excruciatingly tedious albeit crucially important differences in what exactly is sent along and ...well, there we go

[EastonSN+]

11 minutes ago, SBUWX23 said:

I was thinking this the other day. We have been fortunate with some of the historic events in the last 10 or so years. 

70s 80s and 90s. I remember growing up and almost every single channel 2/4/7 weather forecast would start with "snow will be north/well north and west of the city". 2000 through 2018 mirrored 55 through 69 as epic periods which have undoubtedly skewed our seasonal snowfall averages.

[ILoveWinter]

17 minutes ago, WIN said:

It's funny how perspectives have changed over the last 20 years or so. In the 80s and most of the 90s, 4 to 8 was considered a heavy snowstorm.

4-8 in the immediate NYC metro would be amazing considering the garbage we've experience in the past few years but yes in the wider context I agree.

[Typhoon Tip]

17 minutes ago, SBUWX23 said:

I was thinking this the other day. We have been fortunate with some of the historic events in the last 10 or so years. 

Is it possible that some of that 'success' interpretation is attributable to increasing integrated PWAT that's objectively measured everywhere.   I mean shy of invoking the sensitive climate topic ... part of that CC is the increased WV loading, and it's definitively being registered in deposition rates.

Anyway, just wondering if we took system A from 1920 ( say..) and ran it through modeling/reanalysis now, would that same system be more prolific. 

[NJwx85]

3 minutes ago, Typhoon Tip said:

Yeah, it's straight-up a wave addition or not addition taking place between the GFS vs Euro respectively. 

Not sure why the EPO relay is different - that's what I was after in describing the original bifurcation stuff. There's excruciatingly tedious albeit crucially important differences in what exactly is sent along and ...well, there we go

If you look at the last four runs of GFS valid 00z Wednesday the model seems to be handling that piece the same way, albeit with slightly different timing and degrees of amplification. But it is phasing it in rather than shearing it out like the Euro. It would be inaccurate to say that the GFS is trending one way or another. It has been consistent at least over the last 24 hours. We will see what happens with the next run shortly.

[NEG NAO]

5 minutes ago, ILoveWinter said:

4-8 in the immediate NYC metro would be amazing considering the garbage we've experience in the past few years but yes in the wider context I agree.

who is even mentioning 4 - 8 ??? Walt says 1 -3 " right now which is being generous IMO

[RU848789]

3 hours ago, wdrag said:

The Canadian is my winter model of choice for big snow axis. Yes it can be wrong.  I agree with Roger... the Euro is out on its own.  So we/I have to make forecasts and can't worship one model as almighty.  Odds are the EC will be too weak.

Lets forget Feb ahead,  and enjoy the extremes of winter storms that have been presented to us the first 20 days of January here in the eastern USA.

Amazing how fast the power problems of Tuesday were resolved in the USA. Excellent work by the power companies!

Kind of rough near BUF and MKC for the playoff games this weekend, unless they've been moved?

For me, there is little doubt now that a widespread news making hazardous winter event will spread from the Ohio Valley across the I95 megalopolis but impacts still in doubt.  I myself think widespread delays and cancels are coming. NYC-LI probably 1-3" of snow as I see it but could be wrong- rain factor as I buy the much closer to the coast scenario hooking onto the oncoming cold front dropping down Sunday-Monday.  That's Don's stats and some of the modeling am seeing.  

I84: besides looking pretty good for a powdery snowfall Tuesday-early Wednesday, I like the RGEM idea of 1" of snow with a preceding cold frontal passage this Sunday.  

Timing of GEFS storm is a little slower than what I think will occur and storm focus should be, imo, 09z Tue-09z Wed. Uncertainty on timing. 

Adding a bunch of graphics.. btw: 06z GEFS even heavier than its 00z version.  View these as ideas-NOT gospel.

I like WPC dark green (30-49%) axis as the winter hazard concern.   06zGEFS positive snow depth through early Wednesday which includes the stuff from tonight through the weekend. The idea is show how extensive this will be south of 40N. The 24 hour prob 4" from the GEFS, CMCE  and last the EC prob for 4" is lightest. CMCE surprisingly far east. 

I'll check back tonight.  If the future Canadian loses it... then all this is for naught for me. I maintain in large scale synoptic situations here in the northeast...if the Canadian doesn't have it... its an unlikely event. Canadian ia slightly warmer model and you adjust the edges but it's a solid model. 00/12 NAEFS now taking a solid .4" qpf  back ti the Delaware River. 

Walt - great post from someone who has actually had to make NWS forecasts with conflicting/limited data.  The one thing I think many of us don't always think about is that the Euro is the best model - at predicting 500 mbar pressure anomalies globally (that's what the verification scores are based on - and not that that isn't important, but I've never seen "verification scores" for the various models, including the Euro on east coast winter cyclones.  And that's where I think input like yours is really important based on experience and history.  Doesn't mean the Euro can't be right, but one can't automatically think it is just because it's the "best" model.  

On the flip side, I think we've seen a bit of "confirmation bias" (wishcasting just a bit?) over the past 24 hours, where at 0Z 1/11, the Euro was somewhat of a snowy outlier and some were saying it was "leading the pack" and other models would move towards it, somewhat discounting the other 3 globals, but with regard to last night's 0Z runs, with the Euro being a non-snowy outlier, very few are saying the Euro is "leading the pack" and other models will move towards it.  

I'm no expert at all on synoptics, but I've done a lifetime of science where myself and my group had to evaluate scientific models and experimental results (chemical process development in pharma in R&D) and it was always difficult to not give in to confirmation bias, discarding or at least somewhat discounting data one "didn't like." 

Just some observations from the cheap seats - will be interesting to see how this one evolves and we're still 4+ days out with the main energy still way out in the Pacific and not sampled well (no ashore until Sat night/early Sun), plus how today's storm evolves will certainly influence how Tuesday's storm evolves.  One thing for sure: the models will change, especially over the next 24-48 hours, but hopefully not much after that.  That's why tracking is so fascinating.  

[mikem81]

RGEM will be SE of 6Z

[NJwx85]

The 00z GGEM is yet another possibility.

The important Southern stream piece that comes into Oregon tomorrow is seen here off the Northeast coast. It's running so far out ahead of the trough that it doesn't phase in until the system is over Canada and you end up with a very amplified pattern and further West track.

[NEG NAO]

9 minutes ago, NJwx85 said:

If you look at the last four runs of GFS valid 00z Wednesday the model seems to be handling that piece the same way, albeit with slightly different timing and degrees of amplification. But it is phasing it in rather than shearing it out like the Euro. It would be inaccurate to say that the GFS is trending one way or another. It has been consistent at least over the last 24 hours. We will see what happens with the next run shortly.

last 4 runs of just the OP ?

[winterwarlock]

5 minutes ago, NEG NAO said:

who is even mentioning 4 - 8 ??? Walt says 1 -3 " right now which is being generous IMO

there are plenty that like to hug the clown maps verbatim and post them 

[ILoveWinter]

5 minutes ago, NEG NAO said:

who is even mentioning 4 - 8 ??? Walt says 1 -3 " right now which is being generous IMO

Yea was just responding to a previous comment!

[Typhoon Tip]

10 minutes ago, NJwx85 said:

If you look at the last four runs of GFS valid 00z Wednesday the model seems to be handling that piece the same way, albeit with slightly different timing and degrees of amplification. But it is phasing it in rather than shearing it out like the Euro. It would be inaccurate to say that the GFS is trending one way or another. It has been consistent at least over the last 24 hours. We will see what happens with the next run shortly.

Lol... certainly no shortage of adventure - if not 'entertainment'...

[NEG NAO]

12Z ICON

[rclab]

18 minutes ago, WIN said:

It's funny how perspectives have changed over the last 20 years or so. In the 80s and most of the 90s, 4 to 8 was considered a heavy snowstorm.

Good morning WIN. I go back to the 50’s and 60’s. A heavy snow warning was given for an anticipated 4 inches of snow. Early TV forecasts by Dave Garroway and Jack Lescoulie were Quite different from today. Stay, as always.