Yesterday Hurricane Ophelia hit Ireland and the United Kingdom. Yes, the two islands get hit with ferocious storms from time to time, but rarely do they enjoy the hurricanes like we do on the eastern seaboards of Canada, Mexico, and the United States.
Earlier this hurricane season the US had to deal with Harvey, Irma, and Maria. And in early October the Wall Street Journal published a piece that looked at the economic impact of the former two hurricanes as exhibited in economic data.
Overall the piece does a nice job explaining how hurricanes impact different sectors of the economy, well, differently. And wouldn’t you know it that leisure and hospitality is the hardest hit? But then they put together this stacked bar chart showing the impact of the hurricanes on both Florida/Georgia and Texas for Irma and Harvey, respectively.
The problem is that the stacked bar chart does not allow us to examine each hurricane as a specific data set. Because the Harvey data set is first, we have the common baseline and can compare the lengths of the magenta-ish bars. But what about the blue sets for Irma? How large is natural resources and mining compared to professional and business services? It is incredibly difficult to tell because neither bar starts at the same point. You must mentally move the bars to the same baseline and then hope your brain can accurately capture the length.
Instead, a split bar chart with each sector having two bars would have been preferable. Or, barring that, two plots under the same title. Then you could even sort the data sets and make it even easier to see which sectors were more important in the impacted areas.
Stacked bar charts work when you are trying to show total magnitude and the breakdowns are incidental to the point. But as soon as the comparison of the breakdowns becomes important, it’s time to make another chart.
Over the last several weeks we dealt with the impact of a few hurricanes from H to K, i.e. Harvey, Irma, Jose, and Katia. Now that the Atlantic basin has quieted a wee bit, it is time we get back to the lighter side of things.
So we turn to xkcd and its look at ensemble models, often used to try and predict the paths of hurricanes.
Like many Americans I followed the story of Hurricane Irma over the weekend. One of my favourite pieces of reporting was this article from the Washington Post. It did a really nice job of visually comparing Irma to some recent and more historic storms, such as 1992’s Hurricane Andrew.
It can be difficult to truly compare hurricanes, sometimes they are small and compact, other times more dispersed. Irma was just big with lots of potentially destructive power spread out across a wide area, almost the width of the Floridian peninsula. The article uses several graphics—I am also quite partial to the satellite image comparison so check out the article—but this one is perhaps my favourite.
It uses a colour palette that deepens in redness nearer the storm’s centre. This allows the user to compare the geographic area or footprint of the storms destructive winds.
I wonder, however, what would happen if the designers had superimposed each graphic atop the other. It might have allowed for an even better comparison of size instead of having to have the user mentally transpose each hurricane.
Still, a really nice graphic and visual article.
Credit for the piece goes to Bonnie Berkowitz, Laris Karklis, Reuben Fischer-Baum, and Chiqui Esteban.
Your author is on holiday today and is actually writing today’s post on a Thursday night train to Boston. But by the time he returns late Sunday night—a Monday morning post is not guaranteed—Hurricane Irma will have likely made landfall somewhere along the Florida coast.
Thursday the Guardian published a nice article looking at the potential tracks for Irma. And while the specific routes will certainly be amended and updated over the weekend, the article is worth looking at prior to Irma’s arrival at Florida. As of my writing the track has shifted ever slightly westward and the current predicted path looks for Irma to land south and west of Miami. Ergo this screenshot is already a little outdated.
The remarkable thing about this graphic, which is just a cleaner version of the standard meteorological maps through more a more considered palette, is that there is not just one path of winds, but three. Following quickly on the heels of Irma are Katia and Jose, the latter the one taking the nearly same path as Irma while Katia spins towards Mexico.
But the graphic I really wanted to look at is the one ending the piece.
This looks at the countries in Irma’s path as of Thursday morning. What I do not understand is the vertical axis of the bars. What does the height represent? To simply show the rank of countries able to cope with natural disasters, a more straight-forward table could have been used. A dot plot would also make some sense, but again, it would require an understanding of the underlying metrics driving the chart.
The graphic is saved by the annotations, in particular the more/less vulnerable directional arrows. Because I do not understand why countries are grouped into the particular buckets, I find the coloured bins out of place.
I think the concept of showing the most vulnerable countries is terribly important, however, the graphic itself needed a little more thought to be a little more clear in presenting the concept.
Credit for the piece goes to the Guardian graphics department.
Irma swept the northern coast of Puerto Rico last night after devastating some of the Leeward Islands. What’s next? Well after the Turks and Caicos, Cuba, and the Bahamas we are probably looking at a Florida landfall. (Though in the last 24 hours the track has shifted ever eastward so Tampa Bay looks fine from a direct impact standpoint.)
Harvey was an exception in many ways because most deaths occur not from rainfall flooding, but from the storm surge. Basically a massive wave of water driven by low pressure and strong winds that is literally pushed ashore.
Now even though I just said that, I wanted to talk about the winds for a second. Why? Well it turns out that at 185mph, Irma has some of the strongest sustained winds ever recorded for an Atlantic hurricane. And 185mph winds, they can do quite a bit of damage. How much? Well for that we turn to this illustration from Vox.
Assuming the worst case scenario and Irma would strike just southwest of Miami, say Homestead or Key Largo, 185mph winds could do some damage to non-hurricane-safe buildings in a very large American city. And then there is the storm surge, which could be problematic for a city that is already struggling with rising tides. (Thanks, climate change.) The reason I say worst case is southwest of Miami is because hurricanes do most of the their damage—though certainly far from all of it—on their righthand side, which in a northward moving storm would be the eastern half.
The rest of the Vox piece does a nice job explaining Irma, its historic nature, and how it could be so dangerous. Worth a quick read, unless you live in Florida and then you should probably be packing up to evacuate.