Jump to content
  • Member Statistics

    17,601
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

MLK 2022 Storm Potential


stormtracker
 Share

Recommended Posts

Just now, Snowmadness said:

Along time lurker here, can someone tell me why the operational model is so different than the ensembles? I thought OP was a blend of all the ensembles.  18z OP certainly doesn’t look like a blend.  Almost all ensembles have low off the coast?? 

No. The OP is not a blend at all. The OP is the operational run that is run at a higher resolution. The ensembles are different variations of the run at lower resolutions, to depict different scenarios under various tweaked conditions. The ensemble mean is the blend of all ensembles.

  • Like 10
  • Thanks 1
Link to comment
Share on other sites

5 minutes ago, Snowmadness said:

Long time lurker here, can someone tell me why the operational model is so different than the ensembles? I thought OP was a blend of all the ensembles.  18z OP certainly doesn’t look like a blend.  Almost all ensembles have low off the coast?? 

            The ensemble members are run at lower resolution than the operational GFS.    And likely more importantly, the GFS had an upgrade early in 2021 that has not been applied to the GEFS. 

  • Like 3
  • Thanks 2
Link to comment
Share on other sites

7 minutes ago, WinterWxLuvr said:

Don’t disagree on the slowing, but that feature in the ne is definitely speeding up. These maps are at the same time.

BED6B40D-3A0D-452B-86CD-2BF5CF7C08C8.thumb.png.3df511c2479be3ccaeb3cade94263f39.png

3E1171E6-109B-4E50-AF7E-83C7565CB7A7.thumb.png.857ea3973decfe6f752f2a870ce650b8.png

 

That minor a change is noise at that range on an op. But go back 36 hours when I think the storm was as it’s southern most point on models and look at how much the SW has slowed. I agree there has been some weakening of the flow up top but I think the slower progression is the larger influencer. 
 

Say morning the SW is over western KS when 36 hours ago guidance already has it entering the Ohio valley bumping into that confluence and getting squashed.  The SW has also trended stronger and is digging much further west. That change seems a lot more significant than the relatively minor relaxation to the NE. Let’s put it this way, if that SW was as weak as models had it 4-5 runs ago and positively tilted over Indiana instead of cutting off over Kansas Sat morning I am pretty sure it would still be a non event even with the slightly less confluent flow. 

Link to comment
Share on other sites

2 minutes ago, high risk said:

            The ensemble members are run at lower resolution than the operational GFS.    And likely more importantly, the GFS had an upgrade early in 2021 that has not been applied to the GEFS. 

To be fair, that is not an explanation for why. The why is because their algorithm and UL evolution resulted in those evolutions. Different resolution/upgrades are more a testament to higher accuracy (hopefully) and consistency in identifying minutia details and more meso-features. 

Link to comment
Share on other sites

3 minutes ago, psuhoffman said:

That minor a change is noise at that range on an op. But go back 36 hours when I think the storm was as it’s southern most point on models and look at how much the SW has slowed. I agree there has been some weakening of the flow up top but I think the slower progression is the larger influencer. 
 

Say morning the SW is over western KS when 36 hours ago guidance already has it entering the Ohio valley bumping into that confluence and getting squashed.  The SW has also trended stronger and is digging much further west. That change seems a lot more significant than the relatively minor relaxation to the NE. Let’s put it this way, if that SW was as weak as models had it 4-5 runs ago and positively tilted over Indiana instead of cutting off over Kansas Sat morning I am pretty sure it would still be a non event even with the slightly less confluent flow. 

Do you find it strange that the OP has consistently been further west than its own ensembles. Could the OP be seeing something different. Not sure what I would give more weight to at the moment.

Link to comment
Share on other sites

I wonder, have there been any studies on the accuracy of a model at medium to long range when run at different  resolutions? It seems to me that both the Euro and GFS were better at the 5+ day range (more consistent run-to-run) back before the resolution upgrades that started a number of years back. I’m bringing this up because the EPS and GEFS are run at lower resolution and both have eastern tracks vs the op. Wondering if errors are getting amplified at range with these higher resolution models.

  • Like 1
Link to comment
Share on other sites

1 minute ago, Random Chaos said:

I wonder, have there been any studies on the accuracy of a model at medium to long range when run at different  resolutions? It seems to me that both the Euro and GFS were better at the 5+ day range (more consistent run-to-run) back before the resolution upgrades that started a number of years back. I’m bringing this up because the EPS and GEFS are run at lower resolution and both have eastern tracks vs the op. Wondering if errors are getting amplified at range with these higher resolution models.

There are verification scores for each model going out to D6.

Link to comment
Share on other sites

Just now, Random Chaos said:

I wonder, have there been any studies on the accuracy of a model at medium to long range when run at different  resolutions? It seems to me that both the Euro and GFS were better at the 5+ day range (more consistent run-to-run) back before the resolution upgrades that started a number of years back. I’m bringing this up because the EPS and GEFS are run at lower resolution and both have eastern tracks vs the op. Wondering if errors are getting amplified at range with these higher resolution models.

I can't answer to the first part, but because of higher resolution, the permutations these models identify and go in depth on have a greater downstream influence sooner in the run because of their resolution. Obviously, if that happens based on a feature 60 hours into a run, the downstream impact on big picture evolution is further magnified versus a run at lower res. 

Link to comment
Share on other sites

23 minutes ago, Snowmadness said:

Long time lurker here, can someone tell me why the operational model is so different than the ensembles? I thought OP was a blend of all the ensembles.  18z OP certainly doesn’t look like a blend.  Almost all ensembles have low off the coast?? 

Quick and dirty....

Global ops are high(er) resolution mid/long range models. They create a detailed movie every 6-12 hours

Ensemble controls are lower resolution versions of their respective ops but run with identical data at initialization as their respective global ops. When ensemble controls have a significantly different outcome by d4-5 than the operational, the most likely culprit is the high resolution of the op is prob overdoing something. A clue that things are more complicated than they may seem and always tells me to pay closer attention to details 

Ensemble means contain an average of 25-50 low resolution members that each run with slightly different data (perturbations or something like that) than their respective ops and controls. Main reason ens means exist is errors early or at initialization get magnified out in time. Little mistake early = big change later. With Ensemble suites the errors get smoothed (hopefully) and the ens mean output is statistically more likely to happen than the op or controls beyond 4-5 days 

  • Like 11
  • Thanks 9
Link to comment
Share on other sites

12 minutes ago, DDweatherman said:

I can't answer to the first part, but because of higher resolution, the permutations these models identify and go in depth on have a greater downstream influence sooner in the run because of their resolution. Obviously, if that happens based on a feature 60 hours into a run, the downstream impact on big picture evolution is further magnified versus a run at lower res. 

That’s exactly what I was thinking, just wondering if there was a study on it. Not talking verification scores so much as how these permutations are amplified. The raw data ingested is not exact, especially data that originated west of California, and errors or inaccuracies in the data could be amplified in the 5+ day period for us on the east coast in higher resolution models.

Link to comment
Share on other sites

25 minutes ago, high risk said:

            The ensemble members are run at lower resolution than the operational GFS.    And likely more importantly, the GFS had an upgrade early in 2021 that has not been applied to the GEFS. 

 

9 minutes ago, Amped said:

6z also had a pretty big disconnect between the GFS and the GEFS.   Looks a little fishy.  Time to put more trust in the EPS

It seems more than coincidental that the last 3 GFS runs, the GGEM, and the Euro have all been western outliers to their ensemble members.  But I'm not sure how much can be chalked up to simple resolution differences since the EPS members are run at comparable resolution to the GFS operational.  So I'm not sure what's going on.  Luckily this is still 5 days out so we have plenty of time to sort it out.  

  • Like 6
Link to comment
Share on other sites

55 minutes ago, MillvilleWx said:

Guys, it's a deterministic at Day 6. Yes, as it shows, it would be an I-81 special and people east of Rt 15 would get a driving sleet/rain before changing back. There's too many variables on the table to decipher before pegging any particular solution. There could even be a piece that's not even modeled that could throw another variable into the mix. Welcome to the world of chaos with a dynamic fluid that is the atmosphere. 

Bingo. Said this earlier in the other thread. It’s far too early - especially with so many pieces at play and such a dynamic setup - to be worrying about a particular runs surface look on day 6; worrying about p-type and clown maps is ill advised.  

Ensembles, h5, 500mb - my day 6 starter pack for model watching 

For me… what I took out of today is that a clear trend has been set for a significant coastal storm, instead of a far southern slider. Now we let the storm get into the euro and king (new) gfs’s  wheelhouse and iron out things like spacing / location of features, storm track, strength of storm, over the next 2 or so days before we get too excited / worried. When have we ever wanted to be in the jackpot day 5/6 anyhow!?  
 

Thank you for your calming words and of course, all of the knowledge you share here. You, PSU, Bob Chill, and several others here are invaluable to this forum. :clap:

  • Like 3
Link to comment
Share on other sites

13 minutes ago, Bob Chill said:

Quick and dirty....

Global ops are high(er) resolution mid/long range models. They create a detailed movie every 6-12 hours

Ensemble controls are lower resolution versions of their respective ops but run with identical data at initialization as their respective global ops

Ensemble means contain an average of 25-50 low resolution members that each run with slightly different data (perturbations or something like that) than their respective ops and controls. The reasoning behind ens means is errors early get magnified out in time. Little mistake early = big change later. With Ensemble suites the errors get smoothed (hopefully) and the ens mean output is statistically more likely to happen than the op or controls. 

        This is how it *should* be set up, but it's unfortunately not the case right now with the GEFS.    The operational GFS underwent a significant upgrade this past March, including changes to the PBL scheme, radiation, and data assimilation.     Those changes were not made to the GEFS.     So, even the GEFS control run cannot be considered only a lower-resolution version of the operational GFS.     Does that fact that the GEFS members and GFS have larger differences than just resolution explain why no GEFS member looks like the GFS solution?   Impossible to say....

  • Like 4
  • Thanks 2
Link to comment
Share on other sites

One thing in everyones favor is that strong storms running up the coastal plain are pretty rare. I would think it is either going to run the coast or be west.  If it's going to be west it is much more likely to end up a cutter. But that isnt necessarily a complete fail either. We can get a decent front end thump then dryslot with those as well. I just want to give the GFS some kudo's. It has been sniffing around with a MLK storm for over a week now. It hasnt verified yet. But if it does that model has really been improved. 

  • Like 3
Link to comment
Share on other sites

3 minutes ago, WxUSAF said:

 

It seems more than coincidental that the last 3 GFS runs, the GGEM, and the Euro have all been western outliers to their ensemble members.  But I'm not sure how much can be chalked up to simple resolution differences since the EPS members are run at comparable resolution to the GFS operational.  So I'm not sure what's going on.  Luckily this is still 5 days out so we have plenty of time to sort it out.  

         I can't argue with this.     It's certainly possible that higher resolution is the key to a further west solution.    I'm just trying to point out that resolution isn't the only significant difference between the GFS and GEFS.     Really wish that the GFS and GEFS could be upgraded simultaneously.....

  • Like 4
Link to comment
Share on other sites

2 minutes ago, WxUSAF said:

 

It seems more than coincidental that the last 3 GFS runs, the GGEM, and the Euro have all been western outliers to their ensemble members.  But I'm not sure how much can be chalked up to simple resolution differences since the EPS members are run at comparable resolution to the GFS operational.  So I'm not sure what's going on.  Luckily this is still 5 days out so we have plenty of time to sort it out.  

Nothing off the table, could track easily track over Detroit, or end up a cutoff low over Arizona.   There isn't anything really pinning this pattern down.

Link to comment
Share on other sites

4 minutes ago, WxUSAF said:

 

It seems more than coincidental that the last 3 GFS runs, the GGEM, and the Euro have all been western outliers to their ensemble members.  But I'm not sure how much can be chalked up to simple resolution differences since the EPS members are run at comparable resolution to the GFS operational.  So I'm not sure what's going on.  Luckily this is still 5 days out so we have plenty of time to sort it out.  

 

2 minutes ago, high risk said:

        This is how it *should* be set up, but it's unfortunately not the case right now with the GEFS.    The operational GFS underwent a significant upgrade this past March, including changes to the PBL scheme, radiation, and data assimilation.     Those changes were not made to the GEFS.     So, even the GEFS control run cannot be considered only a lower-resolution version of the operational GFS.     Does that fact that the GEFS members and GFS have larger differences than just resolution explain why no GEFS member looks like the GFS solution?   Impossible to say....

It’s intriguing. It’s possible that the resolution is the culprit on the eps and geps but the issue for the Gfs is more to do with the outdated gefs. It is weird that the same phenomenon is showing on all 3 global systems. 
 

@high risk: do you know since the upgrade how the ensembles score at this range compared to the op?  I think we’re still at a range the eps is slightly better than the euro op. 

Link to comment
Share on other sites

3 minutes ago, high risk said:

        This is how it *should* be set up, but it's unfortunately not the case right now with the GEFS.    The operational GFS underwent a significant upgrade this past March, including changes to the PBL scheme, radiation, and data assimilation.     Those changes were not made to the GEFS.     So, even the GEFS control run cannot be considered only a lower-resolution version of the operational GFS.     Does that fact that the GEFS members and GFS have larger differences than just resolution explain why no GEFS member looks like the GFS solution?   Impossible to say....

The operational GFS really was spectacular with the past two systems, so this upgrade seems awesome. I'm sure it's not super easy to just roll it out to the GEFS though. 

In any case, we are tracking a 6-day storm, so we're all definitely still in the game. Next run. 

  • Like 1
Link to comment
Share on other sites

3 minutes ago, high risk said:

         I can't argue with this.     It's certainly possible that higher resolution is the key to a further west solution.    I'm just trying to point out that resolution isn't the only significant difference between the GFS and GEFS.     Really wish that the GFS and GEFS could be upgraded simultaneously.....

When is the gefs getting the upgrade. They still waiting

until the short range fv3 system is ready? 

Link to comment
Share on other sites

2 minutes ago, high risk said:

         I can't argue with this.     It's certainly possible that higher resolution is the key to a further west solution.    I'm just trying to point out that resolution isn't the only significant difference between the GFS and GEFS.     Really wish that the GFS and GEFS could be upgraded simultaneously.....

This is an important point for sure, but the Euro/EPS and GGEM/GEPS having similar looking differences seems very odd.  

  • Like 1
Link to comment
Share on other sites

Just now, psuhoffman said:

 

It’s intriguing. It’s possible that the resolution is the culprit on the eps and geps but the issue for the Gfs is more to do with the outdated gefs. It is weird that the same phenomenon is showing on all 3 global systems. 
 

@high risk: do you know since the upgrade how the ensembles score at this range compared to the op?  I think we’re still at a range the eps is slightly better than the euro op. 

GEFS mean scores are statistically better than deterministic GFS for the medium range....but that has to come with all kinds of caveats (e.g. domain/temporally averaged, not necessarily applicable to individual events, etc.). 

  • Like 3
  • Thanks 8
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...