I think in assessing hurricane prediction and the benefits thereof the best statistics to look at would be the death toll due to hurricanes over time normalized to the strength of the storm. If you look back through the records
Hurricanes in History
you see that death tolls have gone from many hundreds to thousands before the era of satellite weather monitoring to typically dozens more recently. The obvious exception was Katrina, which was not a forecasting failure but one of infrastructure, preparedness and government management after the fact.
There is no denying that the media is a hype-fest in these situations but the NHC tends to provide very sober, detailed and frequently updated information within the limitations of its technical capability. When you are responsible for protecting the public and the data tells you that you have a storm whose intensity tops the charts and whose probable path is potentially catastrophic your only choice is to provide the most accurate outlook.
The real crux of the problem is that evacuation guidance must be given days before landfall to be effective and the chaotic nature of weather systems precludes perfect information that far in advance.
Hurricanes in History
you see that death tolls have gone from many hundreds to thousands before the era of satellite weather monitoring to typically dozens more recently. The obvious exception was Katrina, which was not a forecasting failure but one of infrastructure, preparedness and government management after the fact.
There is no denying that the media is a hype-fest in these situations but the NHC tends to provide very sober, detailed and frequently updated information within the limitations of its technical capability. When you are responsible for protecting the public and the data tells you that you have a storm whose intensity tops the charts and whose probable path is potentially catastrophic your only choice is to provide the most accurate outlook.
The real crux of the problem is that evacuation guidance must be given days before landfall to be effective and the chaotic nature of weather systems precludes perfect information that far in advance.
But is it accurate? No, most of it isn't. the NHC was predicting 6 to 9 feet floods above ground level in my neighborhood, so of course we left. There was no flooding at all here. Other parts of the state are now flooding where flooding was not predicted. Accuracy isn't all that great.
Then there is the media hype. They will pick and choose to find the worst thing they can show, while yelling "Disaster!". And people are so used to it, they believe it and defend the media. This isn't unique to hurricanes, it happens with anything the least bit sensational. The very worst case is shown and implied to be the whole. Hype sells.
I can recall driving back to Ohio from college on I-80 in the late spring of 1972 -- this when I-80 had latrines and few amenities along the route (i.e. no Dutch Pantry at Dubois!) -- there was mud half-way up some of the trees owing to the flooding.
Pano, the accuracy is what it is, pretty damn good 8 hours out and increasingly imprecise the further out the path is predicted. An evacuation warning 8 hours before it hits would cause more deaths and chaos than no warning at all. They are compelled by the time it takes to evacuate an area to make the call before the predicted path cone converges to a narrow band. That is an inevitable consequence of the chaotic nature of weather systems. The alternative would be to put the path cone out there and let folks decide how to interpret it themselves.
And yet if you look over most of the storm, the model did a pretty dang good job. Theres no "prioritize button" for predicting paths when a storm closes in on a major population center that is acutely vulnerable. How much deviation in a model is required to go from 9 ft surge to a foot? I don't know either, but some of the modelling I've been more intimate with suggests those margins are quite small. I'm going to bet that the neither of us know when very effects that caused Irma to deviate drastically from its model emerged, but the reports I've read point to that being a last minute occurrence. It's unfair to blame a model for information it didn't have, and at some point we have to accept the limits of our ability to peer into the future.
No one's model accounted for the late turn. Some times the events are too stochastic. That's not an argument to rest on laurels as it's the 3-4 day prediction data that is probably most actionable.
Yes and yes to all that, I agree. My point is that we believe the models when they are not accurate. But what else are you going to do? Almost everyone in my neighborhood was going to stay, even after evacuation was call for, but when the models called for a 3 or 4 foot storm surge, we all left. That was prudent considering how bad that could be. Later in the storm, like day of, they were calling for 6-9 foot of flood in this area. That's deadly. But it didn't happen - no flooding here at all. Same for most of the Gulf coast.
What has been accurate (enough) is the predicted landfall 24-48 hours out. Beyond that it's a guessing game, a game where the guesses aren't that good. Hurricanes can cause real damage, I've seen it first hand. But we still aren't as good at predicting it as we want to believe.
What has been accurate (enough) is the predicted landfall 24-48 hours out. Beyond that it's a guessing game, a game where the guesses aren't that good. Hurricanes can cause real damage, I've seen it first hand. But we still aren't as good at predicting it as we want to believe.
And may never be given the stochastic nature of these systems.
Sorry, Pano, I read your post more like some of the backlash articles that essentially said, "because the models aren't perfect they're 100% useless," and responded in kind (the things that erode my faith in humanity). My apologies.
Sorry, Pano, I read your post more like some of the backlash articles that essentially said, "because the models aren't perfect they're 100% useless," and responded in kind (the things that erode my faith in humanity). My apologies.
I don't think they are useless, just not nearly as good as we give them credit for. The models predict too many things that don't happen, while missing bad things that do.
Pano, you have to admit too that those storm surge predictions were dependent upon landfall and which locale receives the east side of the eye. As it stands, just a few degrees of difference put the storm into marco area and everyone else was largely spared any flooding. Could the same be said had the storm made landfall in sarasota? Stands to reason points southward would receive a large surge. Practically impossible to predict those couple of degrees. That said, i would also feel as though a giant exercise had been undertaken in light of such little damage. Its for that reason that weather people must not do infotainment or be overly dramatic because it breeds apathy. Shoot, after Charley people were calling for the NHC to stop even putting the line inside the cone, it builds too many expectations.
Yep...I suspect the chaotic nature of large scale weather systems will fundamentally limit the precise prediction of these events early enough to be of use. It's not that the forecast has large error bands because it is flawed, rather the path that the storm takes has a significant degree of variation with time that is not a simple function open to measurement and modeling of atmospheric parameters.
Some of the predictions were completely wrong at the time of landfall.
The map below was current when the hurricane eye passed over my town. Red is 6-9 feet of surge above ground, orange is 3-6 feet. We live in a tiny orange spot surrounded by red. This was current at the time the storm was there and we figured all was lost.
Result? Zero flooding. None anywhere near us. I'm not sure how a prediction could have been more wrong. I'm very glad they were wrong, of course.
Now there is flooding on several rivers in Florida because of all the rain. That's flooding that was either not predicted or not talked about beforehand.
The map below was current when the hurricane eye passed over my town. Red is 6-9 feet of surge above ground, orange is 3-6 feet. We live in a tiny orange spot surrounded by red. This was current at the time the storm was there and we figured all was lost.
Result? Zero flooding. None anywhere near us. I'm not sure how a prediction could have been more wrong. I'm very glad they were wrong, of course.
Now there is flooding on several rivers in Florida because of all the rain. That's flooding that was either not predicted or not talked about beforehand.
Attachments
Pano those forecast misses were a direct result of the path of the storm being inland as it moved up the Florida peninsula rather than tracking up the Gulf coast over the water. Once they forecast what the path will be the strength of the storm along the track and the wind directions relative to the land and the bays are determined by the path.
Yes, Kevin, I understand why it's wrong, just pointing out that when the path was known when the predictions were made - I.E. the storm was passing over and the predictions were still way off. The reason we have predictions is to get an idea of what will happen. It doesn't get much worse than this, no matter the reason.
The reason we have predictions is to get an idea of what will happen. It doesn't get much worse than this, no matter the reason.
Tell that to the 8,000 who died in Galveston in 1900 when a Cat 4 struck with minimal warning...
Hurricanes
Hi there Pano: Happy to hear you and family are ok after the last hurricane and hope your property is not extensively damaged. Understand your position on published information, since we are watching/evaluating the NOAA graphics and reading the "discussion" paragraph for the next TS/now Hurricane JOSE. Predictions are for an off shore pass-by with 30-40mph winds and rain here in Va Beach. Again wishing you and family well. ...regards, Michael
PS: Discussions paragraph on NOAA hurricane site, often cover the subject of "steering of TS/hurricanes.
Yes, Kevin, I understand why it's wrong, just pointing out that when the path was known when the predictions were made - I.E. the storm was passing over and the predictions were still way off. The reason we have predictions is to get an idea of what will happen. It doesn't get much worse than this, no matter the reason.
Hi there Pano: Happy to hear you and family are ok after the last hurricane and hope your property is not extensively damaged. Understand your position on published information, since we are watching/evaluating the NOAA graphics and reading the "discussion" paragraph for the next TS/now Hurricane JOSE. Predictions are for an off shore pass-by with 30-40mph winds and rain here in Va Beach. Again wishing you and family well. ...regards, Michael
PS: Discussions paragraph on NOAA hurricane site, often cover the subject of "steering of TS/hurricanes.
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