We're Trying; But NOT YET--It will still be a Long Time...

[Wthrman13]

This isn't really directed at the NHC. It's more of making a point, that, in spite of it all, nature STILL has the last call...we've got plenty to learn. I've been leary of computer models ever since they came out...but, they are only a tool. They are not the forecast. The best predictor of what this system is going to do is to do it the old fashioned way...follow the barometric pressure in front of it's movement. Whereever it is dropping faster than other areas (even if it's miniscule), will provide us with the answer of where Katrina is going. The models have obviously been pretty confused for a few days with this one...all you have to do is look at them and see that they are confused...they are making wild, radical changes with each run.

Sorry, but since computer models are my area, I have to rise to their defense every once in a while. You are absolutely right, they are only a tool. But regardless, they are the absolute *backbone* of modern weather forecasting. Without the models, we would literally be back in the old days of the 40s, where the best we could do was predict short range movement of pressure systems by the method you mentioned. The problem is, the very method you are espousing is itself much more rife with potential error and ambiguity than a computer model's output. It is useful for short term correction and validation of a storm's potential track, but by and large, the model's reproduce this kind of information rather well. It is by no stretch of the imagination, the *best* way. While old-fashioned means of forecasting the weather may offer nostalgic and educational value, they are vastly inferior to what we can do now with the *proper* use of computer models.

This doesn't mean that computer models don't have their ups and downs, or perform great on every single storm, but I will tell you this, without them, the NHC (and everyone else) would have even less of a clue about what Katrina is going to do then they do now.

I swear, whenever we get a storm where the computer models are in any kind of disagreement, these kind of comments pop up, and I'm reduced to the role of putting out fires...

[mobilebay]

This isn't really directed at the NHC. It's more of making a point, that, in spite of it all, nature STILL has the last call...we've got plenty to learn. I've been leary of computer models ever since they came out...but, they are only a tool. They are not the forecast. The best predictor of what this system is going to do is to do it the old fashioned way...follow the barometric pressure in front of it's movement. Whereever it is dropping faster than other areas (even if it's miniscule), will provide us with the answer of where Katrina is going. The models have obviously been pretty confused for a few days with this one...all you have to do is look at them and see that they are confused...they are making wild, radical changes with each run.

Sorry, but since computer models are my area, I have to rise to their defense every once in a while. You are absolutely right, they are only a tool. But regardless, they are the absolute *backbone* of modern weather forecasting. Without the models, we would literally be back in the old days of the 40s, where the best we could do was predict short range movement of pressure systems by the method you mentioned. The problem is, the very method you are espousing is itself much more rife with potential error and ambiguity than a computer model's output. It is useful for short term correction and validation of a storm's potential track, but by and large, the model's reproduce this kind of information rather well. It is by no stretch of the imagination, the *best* way. While old-fashioned means of forecasting the weather may offer nostalgic and educational value, they are vastly inferior to what we can do now with the *proper* use of computer models.

This doesn't mean that computer models don't have their ups and downs, or perform great on every single storm, but I will tell you this, without them, the NHC (and everyone else) would have even less of a clue about what Katrina is going to do then they do now.

I swear, whenever we get a storm where the computer models are in any kind of disagreement, these kind of comments pop up, and I'm reduced to the role of putting out fires...

These comments are made every time a storm is within 500 miles of New Orleans.

[Wthrman13]

I just need to see some discussion that says Katrina was going to go to Key West since, say, 6:00? Is that enough time??? Can you please post a link, Wthrman13? I'd love to be corrected...but, this system is heading towards Key West or just to the North of there, IT APPEARS?! Show me the discussion, I'd love to read it....

You are overplaying your hand here. The storm, even on it's current vector, will end up well north of Key West. And if you look back over the NHC discussions of the last day, you will indeed find mention of the GFDL model which forecasted this very thing, and you will also find mention that they did not completely discount it. What they did was go with the consensus of the models, which had it further north. That was the best call they could have made at the time.

Simply go the NHC web page and look in their discussion archive.

[Ixolib]

These comments are made every time a storm is within 500 miles of New Orleans.

Well, to be honest, anytime a storm is within 500 miles of ANY populated area!!

[Sean in New Orleans]

Well, we are human and we have absolutely no room for arrogance or I "said so's." Talk about a miss with Katrina...with all of the science, million dollar computers, discussion, intelligence, and the NHC couldn't even predict the path of this system in the next hour!!! Good God. Now, if anyone has seen my posts, they know, I will praise the NHC and have done so in the past, but, this system should make any forecaster or weather afficionado feel humbled. We STILL can't do it...we cannot predict nature completely accurately. We can't even predict with radar, satellite, computers, etc, etc, that a hurricane will shift to the SW within the next hour. And we are discussing that this system will hit Appalachicola?!? LOL, in a real big way. Let's get real. There is no telling where this system is going to go...I don't care what one single person says or argues on this board, or any other board, for that matter. As for my OPINION...this hurricane has just as good a chance of hitting Corpus Christi as it does Appalachicola. Yes...this system could easily continue West clear across the GOM and I'm not being obnoxious here....there are scenario's of this happening and it was even mentioned tonight by WWL's Chief Met Carl Arredondo on the 10:00 news. Now who really knows what is going to happen??? Anyone care to predict the next hour or two!?!?!

Sean I've read your posts. You may not post a lot but when a strom is in the GOM you sure do. I remember you saying the NHC was wrong about Ivan, Dennis, and others. In my opinion This storm will not go any further west than say Pensacola.

Innacurate, and not fair...perhaps you weren't around when I posted this thread.... http://www.storm2k.org/phpbb2/viewtopic.php?t=67409

[mobilebay]

Your right Sean I was out of line. Sorry!

[Sean in New Orleans]

This isn't really directed at the NHC. It's more of making a point, that, in spite of it all, nature STILL has the last call...we've got plenty to learn. I've been leary of computer models ever since they came out...but, they are only a tool. They are not the forecast. The best predictor of what this system is going to do is to do it the old fashioned way...follow the barometric pressure in front of it's movement. Whereever it is dropping faster than other areas (even if it's miniscule), will provide us with the answer of where Katrina is going. The models have obviously been pretty confused for a few days with this one...all you have to do is look at them and see that they are confused...they are making wild, radical changes with each run.

Sorry, but since computer models are my area, I have to rise to their defense every once in a while. You are absolutely right, they are only a tool. But regardless, they are the absolute *backbone* of modern weather forecasting. Without the models, we would literally be back in the old days of the 40s, where the best we could do was predict short range movement of pressure systems by the method you mentioned. The problem is, the very method you are espousing is itself much more rife with potential error and ambiguity than a computer model's output. It is useful for short term correction and validation of a storm's potential track, but by and large, the model's reproduce this kind of information rather well. It is by no stretch of the imagination, the *best* way. While old-fashioned means of forecasting the weather may offer nostalgic and educational value, they are vastly inferior to what we can do now with the *proper* use of computer models.

This doesn't mean that computer models don't have their ups and downs, or perform great on every single storm, but I will tell you this, without them, the NHC (and everyone else) would have even less of a clue about what Katrina is going to do then they do now.

I swear, whenever we get a storm where the computer models are in any kind of disagreement, these kind of comments pop up, and I'm reduced to the role of putting out fires...

I look at computer models, as well...but, since, they are your specialty, maybe you will admit that they need more data inserted into the programs before the public relies on them so heavily. They are a great tool, but, when it comes to nature, they still need plenty more data. They aren't ready for how heavily they are relied upon. And they are right plenty times, but, not enough for "science," IMO. Science is an exact. And computer models are far from exact.

[Sean in New Orleans]

Your right Sean I was out of line. Sorry!

No biggy...We have one thing in common..we love weather. (And I love your hometown, as well)!

[Wthrman13]

This isn't really directed at the NHC. It's more of making a point, that, in spite of it all, nature STILL has the last call...we've got plenty to learn. I've been leary of computer models ever since they came out...but, they are only a tool. They are not the forecast. The best predictor of what this system is going to do is to do it the old fashioned way...follow the barometric pressure in front of it's movement. Whereever it is dropping faster than other areas (even if it's miniscule), will provide us with the answer of where Katrina is going. The models have obviously been pretty confused for a few days with this one...all you have to do is look at them and see that they are confused...they are making wild, radical changes with each run.

Sorry, but since computer models are my area, I have to rise to their defense every once in a while. You are absolutely right, they are only a tool. But regardless, they are the absolute *backbone* of modern weather forecasting. Without the models, we would literally be back in the old days of the 40s, where the best we could do was predict short range movement of pressure systems by the method you mentioned. The problem is, the very method you are espousing is itself much more rife with potential error and ambiguity than a computer model's output. It is useful for short term correction and validation of a storm's potential track, but by and large, the model's reproduce this kind of information rather well. It is by no stretch of the imagination, the *best* way. While old-fashioned means of forecasting the weather may offer nostalgic and educational value, they are vastly inferior to what we can do now with the *proper* use of computer models.

This doesn't mean that computer models don't have their ups and downs, or perform great on every single storm, but I will tell you this, without them, the NHC (and everyone else) would have even less of a clue about what Katrina is going to do then they do now.

I swear, whenever we get a storm where the computer models are in any kind of disagreement, these kind of comments pop up, and I'm reduced to the role of putting out fires...

I look at computer models, as well...but, since, they are your specialty, maybe you will admit that they need more data inserted into the programs before the public relies on them so heavily. They are a great tool, but, when it comes to nature, they still need plenty more data. They aren't ready for how heavily they are relied upon. And they are right plenty times, but, not enough for "science," IMO. Science is an exact. And computer models are far from exact.

Absolutely. I'll be the first to say that models definitely need more data in their initial conditions (also better ways of analyzing the data from multiple disparate sources onto a regular model grid: this is the classic data assimilation problem, which we have been making great strides in recently), as well as much better representations of such physical processes as surface fluxes, turbulence, and cloud microphysics. You will find no argument from me there.

You also hit the nail right on the head, when it comes to the public and computer models. The public (at least that portion that are weather enthusiasts) is trending toward relying on the models too heavily. Even trained meteorologists can fall into this trap. The problem is not that the models are bad, it's that people expect FAR too much out of them, without realizing their many limitations. The expectation of what the models should be able to do has begun to far outpace what they actually can do, to the point where people start actually thinking that we are better off without them. Nothing could be further from the truth. Again, it's all relative. You think the models have problems forecasting the weather? Try taking them away tomorrow and see how quickly our forecasting ability goes down the toilet.

I also disagree with your characterization of the models being out of the realm of science. Without getting into a long discussion about the nature of science, let's just say that most science is nowhere near "exact". Some areas of science are closer than others, and ironically, I think that meteorology is one of those that is very close to "hard" science, since it is essentially a division of physics. At least in meteorology we actually have the thing we are studying right in front of our noses, namely, the atmopshere, and thus we can tell how well our theories are explaining things by simply waiting a few days to see how well our predictions come about. This is the very heart of science. Observation, hypothesis, and testability. Try applying the same criteria to say, paleontology, which deals with unobservable past events, and you'll find that meteorology is on a much firmer footing (at least in my opinion. Note I'm not saying that paleontology is not a science, just that not all sciences are created equal). The fact that the models are not "exact" doesn't make them any less scientific, but the fact that they are continually improving given new understanding of the underlying physics, and new input data, and general refinement and testing, is exactly why they ARE scientific.

[fci]

Wthrman13:
With all due respect, and I am sincere since I am an amatuer and you are a Pro; it is hard for me to read a defense that appears to deny that this time the NHC blew it.

You can cite that:
"Finally, some of the guidance, including the GFDL and UKMET have been showing the possibility of this SW turn for days, and the NHC has been saying as much in their discussions.

Saying it in their discussions and saying it in their forecasts are completely different things!!

Chalk it up to the fact that Mother Nature is the only one who knows what is going to happen and that the NHC uses all of the resources that they have to try to predict what a storm will do.

However, it is pretty lame to credit the NHC for having mentioned it in their discussions. I suspect that residents of the Keys and of South Dade were not all glued to the discussions and "possibility" expressed in the discussions of the storm coming VERY close to them or would dump 12-16 inches on them.

I saw more comments from Derek Ortt about the possible SW movement than from the NHC!!!

Sometimes, you just have to admit that they simply missed it.....
And it WILL happen again since Mother Nature will not be told what to do.
We just have to be diligent to follow storms closely until they are no longer a threat to us and not count on models, forecasters or gut feelings...
NHC guides us but is certainly not to be taken as the gospel

Just my two cents worth and not intended to disrespect at all. I have a world of regard for the NHC and all of the Pro Mets who teach us through S2K.

But let's just admit it when they miss it... and learn from it if possible.

[Wthrman13]

Wthrman13:
With all due respect, and I am sincere since I am an amatuer and you are a Pro; it is hard for me to read a defense that appears to deny that this time the NHC blew it.

You can cite that:
"Finally, some of the guidance, including the GFDL and UKMET have been showing the possibility of this SW turn for days, and the NHC has been saying as much in their discussions.

Saying it in their discussions and saying it in their forecasts are completely different things!!

Chalk it up to the fact that Mother Nature is the only one who knows what is going to happen and that the NHC uses all of the resources that they have to try to predict what a storm will do.

However, it is pretty lame to credit the NHC for having mentioned it in their discussions. I suspect that residents of the Keys and of South Dade were not all glued to the discussions and "possibility" expressed in the discussions of the storm coming VERY close to them or would dump 12-16 inches on them.

I saw more comments from Derek Ortt about the possible SW movement than from the NHC!!!

Sometimes, you just have to admit that they simply missed it.....
And it WILL happen again since Mother Nature will not be told what to do.
We just have to be diligent to follow storms closely until they are no longer a threat to us and not count on models, forecasters or gut feelings...
NHC guides us but is certainly not to be taken as the gospel

Just my two cents worth and not intended to disrespect at all. I have a world of regard for the NHC and all of the Pro Mets who teach us through S2K.

But let's just admit it when they miss it... and learn from it if possible.

No offense taken, and just because someone isn't a "pro met" doesn't mean they don't have a clue either

I was more responding to what I felt to be a somewhat innaccurate characterization of the state of forecasting, and of the computer guidance, than I was to this specific incident where the NHC was wrong in their official forecast. All I was doing was pointing out that they did mention the possibility of a SW turn in their forecast discussions, and also mentioned the large spread of the models. That they failed to "go" with the few models that showed this SW turn should hardly be taken as a sign of their forecast incompetency, so yeah, if people are attacking that, then I am going to defend them. If all they are saying is that because of forecast uncertainty and model uncertainty, the NHC was somewhat off on this particular segment of forecast, then of course it's hard to argue with that, and I don't think I was doing that anywhere in my previous posts.

At any rate, this is one of the reasons why there has been debate recently on whether to keep the forecast track line in the official forecasts released to the public, or whether to just go with the cone. The NHC continually emphasizes the cone of uncertainty and how not just to follow the line of the forecast track when making decisions. Frankly everyone along the south Florida coast was under a hurricane warning and should therefore treat it as if the hurricane were coming right at them, because as we've seen, hurricanes can and do deviate from the exact forecast track.

Unfortunately, the NHC is going to catch the flak any time a storm deviates significantly from their forecast track, despite their continued acknowledgement of the uncertainties in the track forecast and their placement of the uncertainty cone on the official graphics and implicitly in the probability tables.

So, yeah, the exact forecast track was off, but again, the folks in the warning area should have been taking due precautions and keeping up to date. The key is relating to the public both the uncertainties in forecast track, the reality of computer model guidance spread, and the fact that track forecasts really have improved, all at the same time. A tough pill to swallow apparently, but still one that needs to be administered. If someone takes a look at the NHC forecast, sees it going 100 miles north of where he lives and says, "ah, I have nothing to worry about", the NHC/NWS/emergency management officials can hardly be blamed for that.

[Deb321]

I don't take what the NHC says as gospel, but IMO they have done a pretty good job so far. People need to pay attention to the cone of error and not the line within the cone. I was in the eye of both Frances and Jeanne last year and I know the importance of watching the entire warning area. As has been posted here, Mother Nature is in control and with the tools modern technology has given to our Met, Scientists, ect. they can only do the best they can and maybe get it right.

[otowntiger]

Never let your guard down until a storm is pass your latitude or inland.

Actually the old 'north of your lattitude' rule didn't didn't work for Miami. She was well above their lattitude before she turned southwest right at them.

[x-y-no]

Wthrman13:
With all due respect, and I am sincere since I am an amatuer and you are a Pro; it is hard for me to read a defense that appears to deny that this time the NHC blew it.

Erm ...

The hurricane warning area extended down to Florida City, and the tropical storm warning through the Keys and over on the SW coast, IIRC. So how exactly did they "blow it?"

The forecast landfall was about 10 miles north of me over 24 hours out, and the eye went directly over my location. 10 miles aint too shabby at 24 hours, IMHO. So how exactly did they "blow it?"

Intensity was Cat 1 at landfall, and for over a day they were forecasting Cat 1 at landfall. So how exactly did they "blow it?"

[wjs3]

Wthrman & everyone:

Great discussion.

I don't know what other amateurs' experience with model guidance is, but I've been taking meteo classes online, and the end of the class--where we used model guidance to try to forecast even tomorrow's synoptic weather--it's incredibly, incredibly humbling. I think of myself as weather-involved, and some of the blown forecasts...I never realized how hard it was. It's made me look at model guidance at times like this totally differently.

I'd urge everyone who's interested in weather (and who hasn't done this yet--maybe I'm the exception) to try this sometime...read up and try to forecast the weather in your howmetown for the next day or two. Broad strokes are easier, but getting specific--like exactly where it will rain or exactly when the wind will shift...wow.

No, it won't educate the public about the strengths of our understanding of the atmosphere, and the weaknesses too, but let me tell you, it sure has made me a better "consumer" of weather information.

great point, wthrman--this is not quantum physics--we can see everything we are trying to explain and predict. Help me here, though, there are important points about the weather where we see the consequences rather than directly measureing the variable, right? For example vertical motion and vorticity...we can see the results of those--like clearing in sinking air, and divergence/convergence as vorticity changes, but we can't meausre what they are at a specific time in a specific place--right? (Correct me if I'm wrong!)

Great discussion.

[manofsteele79]

Sean,

the part that disturbs me is they had a model, the GFDL, that predicted the WSW then SW movement and it was ignored due to it being an outlier. Just another thing to keep in mind..... human beings created these models so these models are no smarter than the mets.... they just crunch numbers a helluva lot faster.

FYI, Derek Ortt isn't buying the popular Big Bend target (they get targeted regularly, but never have any landfalls it seems).... he's saying Destin and west.

[Wthrman13]

great point, wthrman--this is not quantum physics--we can see everything we are trying to explain and predict. Help me here, though, there are important points about the weather where we see the consequences rather than directly measureing the variable, right? For example vertical motion and vorticity...we can see the results of those--like clearing in sinking air, and divergence/convergence as vorticity changes, but we can't meausre what they are at a specific time in a specific place--right? (Correct me if I'm wrong!)

You are correct. In large scale flows vertical motion is diagnosed (various techniques are available to do this), not actually measured, because large scale vertical motion is usually very weak (on the order of a few centimeters per second). Luckily, vertical motion is coupled to horizontal motion through conservation of mass (the continuity equation), so if you know the horizontal motion field accurately enough, you can get the vertical motion field. In practice, there are enough errors in the measurement of the horizontal motion field to make the retrieved vertical motion field noisy and suspect, so other, more sophisiticated techniques have to be used.

About the only time vertical motion is really actually measured in the atmosphere is when it is strong and localized, and probed with a Doppler radar. This occurs, as you might expect, most often in thunderstorms.

[tronbunny]

wthrman13:

Thank you for your discussion of modeling.
as with computers and programs, they are only as good as the data put into them.
We gather tons of synoptic data, and we use the computer models to 'predict' what happens next. This data is run through algorithms/formulas that are based on physics (more specifically the physics of fluid dynamics). We know a lot about fluid dynamics, but there are still aspects of it that are unquantifiable, so far.
We may miss one tiny measurement in those thousands of bits of synoptic data that changes the outcome of a formula. That is the error factor. If y'all believe that the average human of high intelligence can crunch all those numbers as accurately or quickly as the computer models, you are missing the point.
The models are excellent guides... there is some data that may be missing from all the tons of synoptic measurements that may be observed in ways that are unexplained, by a very talented few meteorologists, that when added to the model runs, come out with an even more accurate picture (data that hasn't yet been added to all the fomulas that the models use, or data that hasn't got a real-hard synoptic measurement point)
Let's not write off the models, combined with the very valuable experience with our scientists at the NHC.

[fci]

Wthrman13:
With all due respect, and I am sincere since I am an amatuer and you are a Pro; it is hard for me to read a defense that appears to deny that this time the NHC blew it.

Erm ...

The hurricane warning area extended down to Florida City, and the tropical storm warning through the Keys and over on the SW coast, IIRC. So how exactly did they "blow it?"

The forecast landfall was about 10 miles north of me over 24 hours out, and the eye went directly over my location. 10 miles aint too shabby at 24 hours, IMHO. So how exactly did they "blow it?"

Intensity was Cat 1 at landfall, and for over a day they were forecasting Cat 1 at landfall. So how exactly did they "blow it?"

Never had a Hurricane Watch for the Keys and they did get Hurricane conditions (or really close to them).

Dade was at the bottom of the Hurricane Warning area and even local Mets predicted the "weaker south side" of the storm for their area.

They had it coming in at about 2 AM Saturday and it came in 8 hours earlier.

NEVER publicly forecasted the turn to the SW. Mentioned in discussions which only weather-nuts like us read.

I still believe that they blew it
Hey, it's my opinion and yours is different and is definitely respected by me but not agreed to.

[CajunMama]

I've read through this thread and I have to say thank you to all those who posted in here. You may not have agreed but you agreed to disagree respectfully and it made reading this thread pleasant. THANK YOU! THANK YOU! THANK YOU!