Analog96 Posted January 7, 2011 Share Posted January 7, 2011 The ECMWF were run 4 times a day? -It seems the GFS has gotten better this year, with the recent upgrade. -A lot of people like to accuse the GFS of flip-flopping. -BUT, is this because of the GFS being a bad model or is it because its run double the amount of times as the ECMWF? -IF the ECMWF were run 4 times a day, would it flip flop a lot too? Thoughts? Link to comment Share on other sites More sharing options...
ayuud Posted January 7, 2011 Share Posted January 7, 2011 The ECMWF were run 4 times a day? -It seems the GFS has gotten better this year, with the recent upgrade. -A lot of people like to accuse the GFS of flip-flopping. -BUT, is this because of the GFS being a bad model or is it because its run double the amount of times as the ECMWF? -IF the ECMWF were run 4 times a day, would it flip flop a lot too? Thoughts? it would be a disaster Link to comment Share on other sites More sharing options...
Ji Posted January 7, 2011 Share Posted January 7, 2011 I miss when the euro ran once a day at 7pm Link to comment Share on other sites More sharing options...
Ellinwood Posted January 7, 2011 Share Posted January 7, 2011 You need to stop making threads about the models, or at least research some of these thoughts that pop into your head first. Link to comment Share on other sites More sharing options...
ravensrule Posted January 7, 2011 Share Posted January 7, 2011 You need to stop making threads about the models, or at least research some of these thoughts that pop into your head first. Fellow Met love you can't beat it. Link to comment Share on other sites More sharing options...
Kelvin Wave Posted January 7, 2011 Share Posted January 7, 2011 The Euro is, on paper, the better of the two models, but it has nothing to do with the fact that it is not run 4x daily. It has a better data pre-processing (assimilation) technique (4D-VAR). This is the key to the Euro's success. It has been shown (can't remember the paper, consult NCEP) that if you take data that has been initialized by the Euro and plug it into the GFS as initial conditions, then the GFS is virtually as good as the Euro. Unfortunately, NCEP has neither the money nor the resources to use 4D VAR (it takes about as long to run the 4D-VAR as it does to run the actual model!). Link to comment Share on other sites More sharing options...
wall_cloud Posted January 7, 2011 Share Posted January 7, 2011 I'm fine with the 2x per day runs of the ECMWF. Ideally I'd like it about 1-2 hrs earlier to give me some more time to peruse the data before my forecast is due but we don't operate under ideal circumstances all the time. Link to comment Share on other sites More sharing options...
Scotty Lightning Posted January 7, 2011 Share Posted January 7, 2011 What if the GFS only ran twice a day? What if radiosondes were launched regularly at 6z and 18z? What if NCEP had a "premium" model page(it would never happen, but fun to think about)? Link to comment Share on other sites More sharing options...
dtk Posted January 7, 2011 Share Posted January 7, 2011 The Euro is, on paper, the better of the two models, but it has nothing to do with the fact that it is not run 4x daily. It has a better data pre-processing (assimilation) technique (4D-VAR). This is the key to the Euro's success. It has been shown (can't remember the paper, consult NCEP) that if you take data that has been initialized by the Euro and plug it into the GFS as initial conditions, then the GFS is virtually as good as the Euro. Unfortunately, NCEP has neither the money nor the resources to use 4D VAR (it takes about as long to run the 4D-VAR as it does to run the actual model!). The first part is debatable, and people keep trying to reference a conference paper that I take great exception to. In fact, the only thing they were able to show is that they were able to mitigate some (not all) of our worst forecasts....they were never able to show that this made the (old version of) GFS "nearly as good as the Euro" on a consistent basis. As you know, initial conditions are created by updating a model forecast / first guess with information from observations (through variational, OI, ensemble, or some other method). There is no way to separate out (completely) the influence of the forecast model from the initial condition....on top of the fact that these things are cycled and have "memory" of previous updates. NCEP (we) are actively pursuing the development of both 4DVAR and hybrid var-ensemble (this development is much closer to being implemented than 4DVAR) techniques for future upgrades; and it's going to be a matter of being creative with resource usage. Lastly, there are plenty of aspects of the EC model that are probably superior to ours (outside of their 4DVAR, which is better than our 3DVAR, I won't argue that). They run at higher resolution, use a different method for solving the dynamics (semi-lagrangian, which developers here have been working on implementing into the GFS), and have substantially different physics. Link to comment Share on other sites More sharing options...
dtk Posted January 7, 2011 Share Posted January 7, 2011 I'm fine with the 2x per day runs of the ECMWF. Ideally I'd like it about 1-2 hrs earlier to give me some more time to peruse the data before my forecast is due but we don't operate under ideal circumstances all the time. And this is one issue we face as we move toward higher resolution and more advanced (expensive) data assimilation techniques. We will never be able to push back delivery times of GFS products, so we have to be more creative about how we implement new things. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 The first part is debatable, and people keep trying to reference a conference paper that I take great exception to. In fact, the only thing they were able to show is that they were able to mitigate some (not all) of our worst forecasts....they were never able to show that this made the (old version of) GFS "nearly as good as the Euro" on a consistent basis. As you know, initial conditions are created by updating a model forecast / first guess with information from observations (through variational, OI, ensemble, or some other method). There is no way to separate out (completely) the influence of the forecast model from the initial condition....on top of the fact that these things are cycled and have "memory" of previous updates. NCEP (we) are actively pursuing the development of both 4DVAR and hybrid var-ensemble (this development is much closer to being implemented than 4DVAR) techniques for future upgrades; and it's going to be a matter of being creative with resource usage. Lastly, there are plenty of aspects of the EC model that are probably superior to ours (outside of their 4DVAR, which is better than our 3DVAR, I won't argue that). They run at higher resolution, use a different method for solving the dynamics (semi-lagrangian, which developers here have been working on implementing into the GFS), and have substantially different physics. A question I always had is how will the modeling community change as we continue to flatten out the rate of improvements in models with the persistent advancement towards the theoretical ceiling. As these developments continue, will we ever reach a day when the GFS is also a "premium" service? While I know law requires it to be in public domain, will that possibly change? Will the ECMWF ever reach a day when they will need to branch into different modeling sub-branches including mesoscale modeling, etc. to keep an overall competitive advantage to justify the premium costs? Link to comment Share on other sites More sharing options...
dtk Posted January 7, 2011 Share Posted January 7, 2011 A question I always had is how will the modeling community change as we continue to flatten out the rate of improvements in models with the persistent advancement towards the theoretical ceiling. As these developments continue, will we ever reach a day when the GFS is also a "premium" service? While I know law requires it to be in public domain, will that possibly change? Will the ECMWF ever reach a day when they will need to branch into different modeling including mesoscale modeling, etc. to keep an overall competitive advantage to justify the premium costs? These are legit questions (and way above my role/pay grade). I do not think you will ever see the GFS (or any NCEP products) become a "premium service", but that is just my feeling. I don't have a feeling as to whether or not this is even good or bad, it's just the reality of the situation. Based on my understanding in how the EC works (and the agreement signed by member states), I don't think they're moving in that direction (I think they're going in the opposite direction, i.e. more emphasis on seasonal/climate prediction). Also, why even bother with a mesoscale model if in the foreseeable future they may be running their global model at higher resolution than we run our regional models? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted January 7, 2011 Share Posted January 7, 2011 These are legit questions (and way above my role/pay grade). I do not think you will ever see the GFS (or any NCEP products) become a "premium service", but that is just my feeling. I don't have a feeling as to whether or not this is even good or bad, it's just the reality of the situation. Based on my understanding in how the EC works (and the agreement signed by member states), I don't think they're moving in that direction (I think they're going in the opposite direction, i.e. more emphasis on seasonal/climate prediction). Also, why even bother with a mesoscale model if in the foreseeable future they may be running their global model at higher resolution than we run our regional models? A thought I had, but I don't think they would want to be running a 4 km global anytime soon. Also, I would have to believe high resolution models in a less aggressively filtered state to preserve things important in microscale/mesoscale (for instance high frequency mountain induced waves) forecasting have a place. No global model, at least to my understanding, would be able to get away with that without increasing the noise levels substantially. I just wasn't sure if ECMWF may someday want to use their model expertise to filter into other model subsets. The increased emphasis on longer range forecasting makes perfect sense though. Link to comment Share on other sites More sharing options...
Huffwx Posted January 7, 2011 Share Posted January 7, 2011 What if you got voted Weenie of the year after spending big $$ for a met degree>> Link to comment Share on other sites More sharing options...
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