Jump to content
  • Member Statistics

    17,588
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Model Mayhem VI


Typhoon Tip

Recommended Posts

  • Replies 2.4k
  • Created
  • Last Reply
24 minutes ago, OceanStWx said:

The GFS yesterday certainly had some vorticity creation, but the 00z Euro run looks solid from a physical stand point. There is a very trackable shortwave that tracks over Vancouver and dives towards the GoM before rounding the corner and coming north.

Yes.

Agreed...I buy the euro.

Link to comment
Share on other sites

4 minutes ago, OceanStWx said:

I've thought for a while that even though we get more snow up here, that threshold for plowing is probably a better indicator of advisory criteria.

And it's kind of their own discretion too on what 2 inches means...they want 2 inches on the road, but I'm sure they've plowed with less than that (esp when 2"+ is forecast) and in some cases only went with treatment when it was barely 2 inches but also kind of slushy or if the forecast was only for 1-2 and they got high end.

Link to comment
Share on other sites

2 minutes ago, 40/70 Benchmark said:

Yes.

Agreed...I buy the euro.

I mean it's totally different from the GFS. The GFS is all southern stream thump followed by the best forcing moving out of most of New England.

The Euro on the other hand gives the best of both worlds, albeit a touch east of where many would like to see it. But then again Feb '13 pulled that off too. Powderfreak doesn't tell tales of that one, but PWM broke its all time snow storm record. 

Link to comment
Share on other sites

Ray, this is precisely opposite from theoretical physics, "...more progressive because there is more margin for error with regard to the degree of phasing...." 

Progressive (i.e., faster velocities in both wave translation and wind field velocities) flows cause havoc with model ability to correctly sync processes in the atmosphere between two disparate sources (phasing).  

There is in fact, less margin for error in faster flows, because less time means less time for forces to meld at all scales - which is what is needed for better phasing; i.e. the greater margin for error is when the flow is more meridional and slows down. 

 

Link to comment
Share on other sites

1 minute ago, OceanStWx said:

I mean it's totally different from the GFS. The GFS is all southern stream thump followed by the best forcing moving out of most of New England.

The Euro on the other hand gives the best of both worlds, albeit a touch east of where many would like to see it. But then again Feb '13 pulled that off too. Powderfreak doesn't tell tales of that one, but PWM broke its all time snow storm record. 

You have better excess to the requisite tools than I, but what do the mid levels look like in that run?

Is there H7 deformation through central MA?

I buy a sharp cut-off in that depiction, but may not be as far east as the algorithm implies...

Link to comment
Share on other sites

1 minute ago, Typhoon Tip said:

Ray, this is precisely opposite from theoretical physics, "...more progressive because there is more margin for error with regard to the degree of phasing...." 

Progressive (i.e., faster velocities in both wave translation and wind field velocities) flows cause havoc with model ability to correctly sync processes in the atmosphere between two disparate sources (phasing).  

There is in fact, less margin for error in faster flows, because less time means less time for forces to meld at all scales - which is what is needed for better phasing; i.e. the greater margin for error is when the flow is more meridional and slows down. 

 

No.

I mean more margin for error with regard to a hugger.

I'm not worried about a whiff.

Link to comment
Share on other sites

2 minutes ago, 40/70 Benchmark said:

You have better excess to the requisite tools than I, but what do the mid levels look like in that run?

Is there H7 deformation through central MA?

I buy a sharp cut-off in that depiction, but may not be as far east as the algorithm implies...

I'm sure your opulence is just fine.

Link to comment
Share on other sites

1 minute ago, 40/70 Benchmark said:

You have better excess to the requisite tools than I, but what do the mid levels look like in that run?

Is there H7 deformation through central MA?

I buy a sharp cut-off in that depiction, but may not be as far east as the algorithm implies...

Euro takes a closed H7 low from HAT to the benchmark, so definitely a little east for our QPF queen crowd. But the GFS hints at closing a low near PHL and then rots it over ALB. 

Link to comment
Share on other sites

Which brings me to the obvious ... 

This thing is not really phasing with very good efficiency across the operational guidance sources, per the 00z run.  It's probably about ...estimating, 60% ..

The teller on that is that the "southern component" impulse is outpacing the N stream and ending up into the lower/SW Maritime region well prior to the n-stream mid-levels closing off and moving either over the Del Marva, or...right over top SNE. 

The 'right over top' appears to be more of a GFS characteristic ...one that began at 18z yesterday.  It's not good.  ...if one wants maximizing potential for our lat/lon, you want 500 mb surface/closures/translations to move 'under' Long Island... It's no wonder (for me) that the 00z threatened to bring the lower level reflection up the Hudson (whether succeeding to actually do so or not...) with that mid level track(s).  In fact, the 700 mb clearly shows a tendency for dry slot intrusion as that particular circulation level in that 00z run was cutting it really close to moving west of Boston.  It seems to just avoid that, but not before you see a pretty clear pinching off of the higher RH at that level punching over the interior after an event front-side burst.  

So why the outpace?  

It's an interesting sort of 'chicken vs egg' solution.  In one respect, the slightly flatter western ridge, increases the west-east wind velocities everywhere, which then means the intermediate and/or southern stream Pacific dynamics are really scooting along as they dive at a shallower angle ..roughly around the Nebraska or so... Then, this is enough to entice the n-stream fragmentation of deeper cold heights to begin the subsume process, but it's all metaphoric to inviting the guest but failing to wait at the door.  The guess shows up but the host is gone off onto to better things...  

Contrasting, the flow needs to be a little more N-S in orientation, to swap out some of those velocities and put that dynamic into curving flows, ...that will help slow the whole system down and allow said host aloft time to really give the guest the warm welcome (well...in this case, 'cold' would be preferred) it deserves.  

It is true that yesterday there were questions as to the whether lead s/w (which is ultimately the trigger for the phase) was spuriously handled but, at least from what I posted on the subject matter, I was clear to point out that as an option, the s/w may be real, just that there may be too much response to it's presence near the SE coast because of the inherent instability that will be in that region when that feature nears. I little too much boom boom takes off and feeds back..etc. That could still be case... However, I think this whole situation has an endemic uncertainty wrt to the degree of phasing, more so than the primary issue over whether there will actually be a scenario along the EC offering impact. 

Link to comment
Share on other sites

15 minutes ago, 40/70 Benchmark said:

No.

I mean more margin for error with regard to a hugger.

I'm not worried about a whiff.

You said, "degree of phasing"  ... I stopped there - my bad, but that sounds like you directly inferred that progressive flows are better - which they are not.  oh well -

Link to comment
Share on other sites

6 minutes ago, OceanStWx said:

Checking the GEFS ensemble sensitivity, the biggest variance is a left/right track. A coherent H5 signal doesn't show up until around 48 to 60 hours (from 00z last night).

A stronger kicker coming down from northern Canada leads to a more tucked surface low.

yeah...this is what I'm wondering actually... 

I remember prior to the fabled April 1997 Fool's Day event there were products that shaded the 'spread' ...and said spread was smeared well west at D6 ... That was an indication that there were arguments among the member as to whether the D 6 position (at the time, SE of NS) should actually be closer to Cape Cod. 

Well...how'd that work out - 

I'm just wondering if you folks still use those tools/visual aids? 

Link to comment
Share on other sites

6 minutes ago, Typhoon Tip said:

You said, "degree of phasing"  ... I stopped there - my bad, but that sounds like you directly inferred that progressive flows are better - which they are not.  oh well -

All I meant was that if the trough is more progressive, we may be able to get away with a little more phasing....maybe I'm off on that.

Not trying to be an a$$...sometimes is just works out that way. :lol:

Link to comment
Share on other sites

1 minute ago, Typhoon Tip said:

yeah...this is what I'm wondering actually... 

I remember prior to the fabled April 1997 Fool's Day event there were products that shaded the 'spread' ...and said spread was smeared well west at D6 ... That was an indication that there were arguments among the member as to whether the D 6 position (at the time, SE of NS) should actually be closer to Cape Cod. 

Well...how'd that work out - 

I'm just wondering if you folks still use those tools/visual aids? 

Yes we do, but the transition is more towards variance of each type of spread. Like the GEFS have about 60% of the variance in outcomes explained by a left/right track spread. 20% is explained by a faster/slower track spread. So it's definitely a more detailed ensemble spread view.

Link to comment
Share on other sites

The EPS variance is a little more muddled, 40% of the variance is explained by an intensity difference south of New England. A weaker H5 wave topping the western CONUS ridge leads to a weaker low south of New England. But again 20% of the variance is explained by a faster/slower low track.

Link to comment
Share on other sites

I think some can still get locked into an op solution or micro analzye it at 4 days out, come up with thoughts....then next run it swings towards the other goal post. Thoughts either change or dont believe it. Due to the absurd consistency, it may feel like we are inside op range when we still arent quite there yet.

Link to comment
Share on other sites

3 minutes ago, OceanStWx said:

The EPS variance is a little more muddled, 40% of the variance is explained by an intensity difference south of New England. A weaker H5 wave topping the western CONUS ridge leads to a weaker low south of New England. But again 20% of the variance is explained by a faster/slower low track.

Hence the east track at the surface.

Link to comment
Share on other sites

3 minutes ago, 40/70 Benchmark said:

All I meant was that if the trough is more progressive, we may be able to get away with a little more phasing....maybe I'm off on that.

Not trying to be an a$$...sometimes is just works out that way. :lol:

Well, there is some truth to that, actually. Heh. 

All atmospheric wave phenomenon decay along a sinusoidal oscillatory wave dynamic.  

this is also true in the 'emergent totals' of wave interactions, too, whether constructive of destructive ...etc.  

So, taking that logic further ... most of what we see are the first order derivatives along those decaying curves.  But, mathematically it stands to reason that somewhere out there amid the slowly diminishing undulation of energy dynamics, a progressive system will pass through a set of variances that allow a briefer window of opportunity for some degree of phasing.   

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...