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Misinterpreting hurricane forecasts

nytimes.com

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Re: Misinterpreting hurricane forecasts

#51

Post by [deleted] »

matwood wrote: post #39
acchow wrote: post #10

"The National Hurricane Center says cones will contain the path of the storm center only 60 to 70 percent of the time" Sounds like the communications fix is easy. Increase the uncertainty to 90-95% which also increases the cone size. And make it blood red and tell anyone inside the red that they need to be prepared. "Hurricanes are also hundreds of miles wide, and the cone shows only the possible path of the storm’s…

I've been living with hurricanes my entire life, and have been through many (the largest was Hugo in '89). The problem with all these cones is when they extend them beyond 72 hours. At that point, if we used your suggestion, the entire east coast could be in the cone. That means either no one pays attention, or everyone evacuates and next time ignores the warnings. What officials (and the news) need to do is tell eve…

[deleted]

Re: Misinterpreting hurricane forecasts

#52

Post by vallismortis »

acchow wrote: post #10

"The National Hurricane Center says cones will contain the path of the storm center only 60 to 70 percent of the time" Sounds like the communications fix is easy. Increase the uncertainty to 90-95% which also increases the cone size. And make it blood red and tell anyone inside the red that they need to be prepared. "Hurricanes are also hundreds of miles wide, and the cone shows only the possible path of the storm’s…

That won't fix the problem. The NHC uses an ocean model, but the transition across Florida requires the application of a hybrid land/water model, which results in a large divergence when the results of the different models are combined. Fortunately, someone from Mississippi State University developed such a model in 2004. It successfully predicted the exact path of Hurricane Katrina over a week in advance of landfall. That weather model is used for XM Sattelite Weather and the Gulf Coast Hurricane Index, but the NHC still hasn't adopted it after 15 years.

Re: Misinterpreting hurricane forecasts

#53

Post by 2bitencryption »

Fun fact about Dorian right now: the tried-and-true European system predicts the hurricane will head up the opposite Florida coast as the new-hotness of the updated GFS[0]. Who will be right (or will both be wrong?). Will be interesting to see.

[0] https://twitter.com/GregDeeWeather/status/116668585469538304...

Re: Misinterpreting hurricane forecasts

#54

Post by nightski »

_ea1k wrote: post #48
spectramax wrote: post #45

Earlier quoted context omitted.

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.

Re: Misinterpreting hurricane forecasts

#55

Post by brokensegue »

acchow wrote: post #10

"The National Hurricane Center says cones will contain the path of the storm center only 60 to 70 percent of the time" Sounds like the communications fix is easy. Increase the uncertainty to 90-95% which also increases the cone size. And make it blood red and tell anyone inside the red that they need to be prepared. "Hurricanes are also hundreds of miles wide, and the cone shows only the possible path of the storm’s…

people are really bad at understanding probabilities. just look at people's interpretations of polling analysis before the 2016 election. or people's complaints of missing 95% shots in xcom.

Re: Misinterpreting hurricane forecasts

#56

Post by albertocairo »

_ea1k wrote: post #25

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. 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 Hur…

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.

Re: Misinterpreting hurricane forecasts

#57

Post by albertocairo »

albertocairo wrote: post #56
_ea1k wrote: post #25

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. 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 Hur…

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 s…

By the way, thank you for being so thorough and attentive.

Re: Misinterpreting hurricane forecasts

#58

Post by albertocairo »

nightski wrote: post #54
_ea1k wrote: post #48

Earlier quoted context omitted.

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).

Re: Misinterpreting hurricane forecasts

#59

Post by 75dvtwin »

Relying on modern day 'journalists' to interpret weather (or anything else requiring domain expertise, for that matter) -- is very questionable.

Why not use windy.com pick a model (the exceptionally well designed UI, makes it easy), and let it play out the tracks.

https://www.windy.com/22.837/-67.544?27.897,-66.753,5

They have 4 models, and it just as easy to use as posting stuff on Instagram or something..

Meteorologists covering those events, are not journalists, which is good. I trust their coverage more.

Re: Misinterpreting hurricane forecasts

#60

Post by albertocairo »

Jabbles wrote: post #44
_ea1k wrote: post #25

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. 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 Hur…

That is very concerning. Here's an article written at the time: https://www.washingtonpost.com/graphics/2017/national/hurric... "Forecasting models predicted the storm’s path with relative accuracy."

Forecasts are getting better and better, but they still have large uncertainty. The piece explains the cone as the NHC itself explains it. Scroll down here: https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/204603.s...
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