This article is a little bit misleading, unless I am misinterpreting his pictures. But that would be horrible for an article trying to explain pictures.
Now note the image that the article depicts for Hurricane Irma with this text:
"These misunderstandings have real-world consequences. As Hurricane Irma approached Florida’s east coast in 2017, people near the cone’s center began preparing and even evacuating."
The image and the graphical archive do not correlate. Where did the author get this image from? The actual NHC cone covers the entire width of Florida (apart from maybe the smallest western tip of the keys) for days before the storm arrives. Its actually pretty accurate.
IMO, this article and its poor visualizations is part of the problem.
Hi Jsight, Alberto Cairo here. I wrote the piece, but didn't design the maps, so I'll ask.
In any case, even if there's an inconsistency between the maps in the piece—which are intended to be illustrative, I guess—and the NHC ones, it doesn't undermine, I think, the overall message, which is that, regardless of whether you are inside of the cone or outside and close to it, it's safer to prepare just in case.
People should pay less attention to the center dots or line of the cone (many do that) and focus more on facts such as that (a) the cone is essentially tons of possible positions of the center of the storm in the next few days, (b) the storm may end up going outside of the cone 1/3 of the time (so I'd say it doesn't matter much that, say, Naples is outside of the cone, but very close to it on the map.)
I've been in Miami since 2012 and lived through Irma, so I remember what I wrote in the piece well. When the central line of the cone was running over Miami, people over here got crazy, and people on the West coast of Florida were watchful, but a bit less concerned (there's a link to an LATimes article in the piece that describes that), again likely because some folks tend to focus too much on the center line and dots inside the cone. There's tons of evidence for this kind of misinterpretation (one academic paper is linked from the piece).
The piece was reviewed by scientists at UM's School of Marine and Atmospheric Sciences; I won't say it's 100% correct, but I'm relatively confident the description, albeit simplified (I didn't explain what that "uncertainty" is for, instance!), is sound.
Truly nice of you to comment but did you not review the graphics and the source of them to make sure they matched your narrative? Seems important considering it is a piece about graphics and interpretation.
Again appreciate you taking the time to join the discussion.
Having been raised in Florida, you live through so many which are hyped up and so many of them end up missing or diverting away from the state altogether that people get cocky about it. Getting hit by the eye of the hurricane is much different than getting hit by the outer bands or even the middle core of it. The strongest winds are near the eye. The rest of the storm can still do rain and wind damage but it's nowhere near as bad, so it's easy to fall in to false sense of security. That being said, it's also easy to over-worry.
Having lived in Florida for many year, I'll say hurricanes are terribly destructive but in most* cases, the risk to humans is minimal. Stay in your house (unless it's a prefab), or go down the local shelter.
The worst parts of a hurricane are property damage, lost power, no gas, etc. It's much different than a wildfire or a tornado.
Call me an idiot, but risk vs reward...I'm gonna stay put. I've saved thousands in property damage that way too.
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* If you build a city below sea level, that can turn out pretty bad. Also, if you are in poor health, live directly on the beach, or live somewhere without shelters or robust infrastructure.
Risks are higher at the center of the cone. A hypothetical 100 mile wide storm that’s 40 miles west of the centerline still covers the centerline, but likely misses the eastern edge.
Also, staggered evacuation is a good thing, you don’t want everyone in a city to decide to leave at the same time.
That might be true mathematically but talking to forecasters who work on this, they greatly de-emphasize the center line. Instead, they do emphasize that the forecast is the cone, not the center line alone. They direct your attention away from the center line (readers tend to stick too much to it), and say something similar to what is in the article: areas outside will be likely affected, everyone should take precautions and prepare regardless of where we are — and we should read other graphics and messages that can tell us, for instance, whether there may be storm surge, flooding, or whether we need to evacuate or not; the cone tells us nothing about any of that.
One last thing: risks aren't necessarily higher on the center line. Just to give you an example: if you live in a low-level region far from the center line but that is prone to flooding, risks may be higher than if you are by the line but your house is on high ground (again, the cone says nothing about hazards, as pointed out).
The general problem that the article raises is still valid even though the pictures don’t match.
The article is pointing out that the increasing circle sizes represent variation of centerline paths, not the actual size of the hurricane (which is a common misconception). Just because the plots don’t match doesn’t make the article irrelevant.
I get your point, but there is another angle here. People have a strong tendency not to trust forecasters, despite relative accuracy. This article implies a lack of accuracy that wasn't actually the case.
It would be incredibly easy to come away from this article with the wrong lessons.
Where do you see the article implying the forecast was inaccurate? To me the author is only saying that how people interpret it is inaccurate which is the entire point of the article.
Yes, exactly. The cone is as accurate as it can be, by which I mean: accurate but with a huge degree of uncertainty. The challenge is that some readers tend to read it as deterministic, and get it wrong by:
1. Thinking "If I'm inside of the cone I'm in danger, if I'm outside I'm good" (wrong! 1/3 of the time the storm will be outside of the cone!)
2. If I'm inside of the cone AND under its center line/dots of I'll worry a lot, but if I'm inside and in between the center of the cone and its boundary, I can relax (I'd be VERY careful with this, as it isn't true either).
And your article drives this point home really well. I honestly don't understand the criticism - the hurricane example you picked from 2017 is just to make a point - which people in this thread are unnecessarily complaining about.
> People have a strong tendency not to trust forecasters
It's possible a lot of this bias is just outdated, up until very recently most hurricane (cyclone in my case) warnings came with a disclaimer like "cyclones or notoriously unpredictable and can make sudden, unexpected course changes" and for the most part this was true even in the short term. I don't think I've seen a wildly incorrect forecast in my area in 20 years but my mother still believes in this inherent unpredictability.
The challenge is that, eventually, the forecast of one storm will be wildly off. This is inevitable. But that doesn't mean that the forecast was necessarily incorrect. I think that this is what it's crucial to explain to the public: the general meaning of uncertainty. We need to learn to deal with it.
Why use a real-world example if it's not going to be based on data? Surely if the numbers are correct that there's 60-70% accuracy with the cone (on any particular day? or possibly early on) then they could use real data.
It also starts with "The National Hurricane Center publishes graphics like this one" (with "graphics" directly linking to a different graph than the one shown [1]) which would lead one to believe it was an actual NHC example being challenged.
The general point can still get across but its just important to choose your anecdotes carefully if you want to be taken seriously.
Especially in the hyper-critical social media age when everyone is looking to kick anything popular down a peg or two, for their own personal satisfaction of being smart (or w/e the motivation is).
This is extreme. Why use a real-world example? Because people can relate to it. People have seen these types of plots. It could have been a completely fabricated example of an arbitrary hurricane in Florida or Canada or whatever - the point would still be the same. I feel like people are completely missing the point of the article.
Also, my question is : what are the wrong lessons that this article teaches?
A whole lot of people who are the target market for this article would likely have experienced the same hurricane. Not giving the peanut gallery easy reasons for dismissal is something to be considered.
> Surely if the numbers are correct that there's 60-70% accuracy with the cone (on any particular day? or possibly early on) then they could use real data.
I've noticed this as well. In reality, outside the cone seems to happen pretty regularly. So far outside the cone that it is significant as a practical matter is much more rare, at least in terms of the 48 hour cone.
> Especially in the hyper-critical social media age when everyone is looking to kick anything popular down a peg or two, for their own personal satisfaction of being smart
NHC tropical cyclone forecast tracks can be in error. This forecast uncertainty is conveyed by the track forecast "cone", the solid white and stippled white areas in the graphic. The solid white area depicts the track forecast uncertainty for days 1-3 of the forecast, while the stippled area depicts the uncertainty on days 4-5. Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time. To form the cone, a set of imaginary circles are placed along the forecast track at the 12, 24, 36, 48, 72, 96, and 120 h positions, where the size of each circle is set so that it encloses 67% of the previous five years official forecast errors. The cone is then formed by smoothly connecting the area swept out by the set of circles.
It is also important to realize that a tropical cyclone is not a point. Their effects can span many hundreds of miles from the center. The area experiencing hurricane force (one-minute average wind speeds of at least 74 mph) and tropical storm force (one-minute average wind speeds of 39-73 mph) winds can extend well beyond the white areas shown enclosing the most likely track area of the center. The distribution of hurricane and tropical storm force winds in this tropical cyclone can be seen in the Wind History graphic linked above.
Considering the combined forecast uncertainties in track, intensity, and size, the chances that any particular location will experience winds of 34 kt (tropical storm force), 50 kt, or 64 kt (hurricane force) from this tropical cyclone are presented in tabular form for selected locations and forecast positions. This information is also presented in graphical form for the 34 kt, 50 kt, and 64 kt thresholds.
The article is trying to explain what a confidence interval is. I think it does a good job and connecting it with real world consequence of where statistical representations and interpretation lead to people being complacent about risks.
Here is the graphical archive for all 5 day forecasts of Irma: https://www.nhc.noaa.gov/archive/2017/IRMA_graphics.php?prod...
Now note the image that the article depicts for Hurricane Irma with this text: "These misunderstandings have real-world consequences. As Hurricane Irma approached Florida’s east coast in 2017, people near the cone’s center began preparing and even evacuating."
The image and the graphical archive do not correlate. Where did the author get this image from? The actual NHC cone covers the entire width of Florida (apart from maybe the smallest western tip of the keys) for days before the storm arrives. Its actually pretty accurate.
IMO, this article and its poor visualizations is part of the problem.