Rethinking the Cone of Uncertainty

A feature of hurricane maps is the so-called cone of uncertainty, which shows the range of likely paths the hurricane is forecasted to follow. The problem is that the cone of uncertainty is easily misinterpreted by the reader. The MIT Technology Review’s Karen Hao looks at five ways the cone can be misinterpreted, along with some alternative methods of visualizing a hurricane’s projected path. [Gretchen Peterson]

Hurricane Michael’s Impact

It’s after the fact, at least in terms of initial landfall (if not aftermath), but maps I’ve seen of Hurricane Michael include the USGS’s Hurricane Michael page, which includes an event support map and a map of coastal change impacts; and imagery from the Suomi NPP satellite that shows the path of Hurricane Michael through the power outages left in the storm’s wake.

When Mobile Maps Can’t Keep Up with Road Closures

During a natural disaster like Hurricane Florence, crisis maps can be an invaluable source of information about road and bridge closures and other infrastructure outages. Trouble is, that information doesn’t always trickle down to mobile phones, which is where most people get their maps. (Especially when authorities have trouble keeping up with road closures on their own maps.) CityLab’s Clare Tran explores this question, looking at, for example, how Waze incorporates road closure data from Esri and its volunteers.

Hurricane Florence: A Link Roundup

Hurricane Florence on 12 September 2018, as seen by NASA’s Terra Satellite.

The Washington Post has maps tracking Hurricane Florence’s forecasted path and its potential impact. Researcher Eira Tansey compiled data from several NOAA sources—hurricane track forecasting, potential storm surge flooding and long-duration hazards—to create this map.

A variety of NASA imagery of the storm is available via this Twitter moment. The eye of the storm can be viewed on Google Earth’s Current Weather Radar layer (Chrome-only).

Direct Relief’s Hurricane Florence Social Vulnerability Dashboard shows the extent to which the population in Florence’s path will be disproportionately affected by the storm. As CityLab’s Nicole Javorksy explains, while coastal areas will be hit hardest, residents there are more affluent; socioeconomic status, age, disability status, car ownership can all determine one’s ability to endure or recover from a storm.

The New York Times maps the environmental hazards in Florence’s path: “ponds of coal ash, Superfund sites, chemical plants—and thousands of industrial hog farms with lagoons filled with pig waste.” All have the potential to cause widespread contamination if flooded.

Hurricanes and Aerosols

NASA Goddard

NASA’s Goddard Space Flight Center produced this visualization, based on computer modelling and data from Earth observing satellites, tracking how hurricanes transport sea salt, dust, and smoke across the globe.

During the 2017 hurricane season, the storms are visible because of the sea salt that is captured by the storms. Strong winds at the surface lift the sea salt into the atmosphere and the particles are incorporated into the storm. Hurricane Irma is the first big storm that spawns off the coast of Africa. As the storm spins up, the Saharan dust is absorbed in cloud droplets and washed out of the storm as rain. This process happens with most of the storms, except for Hurricane Ophelia. Forming more northward than most storms, Ophelia traveled to the east picking up dust from the Sahara and smoke from large fires in Portugal. Retaining its tropical storm state farther northward than any system in the Atlantic, Ophelia carried the smoke and dust into Ireland and the UK.

Video at the link, or here’s the YouTube version. [APOD/Kottke]

Crowdsourced Satellite Image Analysis

There are many circumstances where the amount of data vastly exceeds the ability to process and analyze it—and computers can only do so much. Enter crowdsourcing. Steve Coast points to Digital Globe’s Tomnod project, which basically crowdsources satellite image analysis. In the case of the current project to  map the presence of Weddell seals on the Antarctic Peninsula and the ice floes of the Weddell Sea, users are given an image tile and asked to indicate whether there are seals in the image. It’s harder than it looks, but it’s the kind of routine task that most people can do—many hands, light work and all that—and it helps researchers focus their attention where it needs focusing. (A similar campaign for the Ross Sea took place in 2016.)

Another ongoing campaign asks users to identify flooded and damaged infrastructure and trash heaps in post-Hurricane Maria Puerto Rico.

Volunteers Mapping Post-Hurricane Puerto Rico

When disaster strikes, crowdmapping kicks into high gear. Last Friday, six universities hosted mapathons where volunteers, using satellite imagery, contributed to the map of Puerto Rico and other hurricane-damaged areas on OpenStreetMap. More from one of the universities involved. Here’s the relevant project page on the OSM Wiki.

Mapping the Damage in Puerto Rico


At NASA’s Earth Observatory, before and after images of Puerto Rico’s nighttime lights illustrate the extent of power outages and infrastructure damage on the island. NASA has also produced a map of likely damaged areas of eastern Puerto Rico, based on before and after radar satellite interferometry and similar to the map they produced for the Mexican earthquake. At ground level, the CrowdRescue Puerto Rico Infrastructure Map displays crowdsourced reports of damage—downed power lines, bridge collapses, floods, mudslides and other incidents.

Looking Back at Hurricane Harvey’s Impact

Here’s a CBS News gallery of before-and-after images showing the impact of flooding in the wake of Hurricane Harvey. The page is undated but was published on 1 September. [Dave Smith]

And, via CityLab, here are a set of maps from the Urban Institute that show the impact of Hurricane Harvey on Houston’s neighbourhoods, based on income levels, home ownership rates, accumulated-equity rates, all of which looking at the economic impact of the storm. “Harvey’s aftermath puts an enormous hurdle in front of all homeowners and renters but will be a particular setback for low-income, minority families recovering from the 2008 housing bust.”

Previously: Mapping Hurricane Harvey’s Impact.

Maria’s Deluge

Some of the most striking maps of the recent bout of hurricanes have involved the sheer amount of water dropped by these storms. (See previous posts on Harvey and Irma.) Above, a is a short NASA video showing Maria’s track through the Caribbean, dumping water in its wake.

Relatedly, the Washington Post produced maps of precipitation and river gauge levels on Puerto Rico that show just how much water Maria threw at that island.

Washington Post

Tracking Hurricane Irma

Washington Post

As they did with Hurricane Harvey, both the New York Times and the Washington Post graphics departments have frequently updated map pages showing the projected path and impact of Hurricane Irma. The Times’ page looks at the hurricane’s current and projected path, threat of coastal flooding, and areas under evacuation, plus some context; the Post maps Irma’s forecasted path on this page and the potential storm surge and evacuation zones on this page, while this page compares Irma’s size to past hurricanes.

Debunking a Fake Hurricane Map

Also from last week: someone on Facebook circulated a map showing the path of Hurricane Irma hitting Houston, prompting the National Weather Service to issue a warning on Twitter about fake forecasts (real forecasts only go out five days). Media factchecking service PolitiFact has the details. Fun fact: making a counterfeit or false weather forecast is an offense in the United States.