Hurricane Winds
A hurricane is a type of tropical cyclone distinguished by an area of low pressure, clouds rotating counter-clockwise, and maximum sustained winds of at least 74 mph. Hurricanes are some of the most destructive natural events in the United States, but planning and responding to these storms is challenging due to their unpredictable paths and intensities.
The UrbanFootprint Hurricane Wind Risk Model estimates the current and future annual probability of hurricane-force winds on a national 0.1 x 0.1-degree grid.
Example Maps in Analyst
This pair of images showcases how you can visualize hurricanes in Analyst. In these examples, there is an increased annual probability of Category 1 or stronger hurricanes, with more areas exposed to hurricanes in the future scenario.
Current scenario
SSP5-8.5 scenario
Details
As input, we use datasets that include 10,000 years of synthetic tropical cyclone (hurricanes) tracks for current (Blomendaal et al. (2020)) and future (Bloemendaal et al. (2022)) periods. We model hurricane winds for each storm track and generate a wind distribution at each grid cell. Using a Generalized Pareto Distribution (GPD), we fit the tail of the distributions to estimate the frequency of exceedance for hurricanes based on the Saffir-Simpson Hurricane Wind Scale. Once the distribution is fit, we calculate the survival function for each wind speed of interest (33 m/s-70 m/s). We then multiply this by the total number of hurricanes with wind speeds above the threshold to obtain the expected number of such hurricanes over 10,000 years. Dividing this number by 10,000 gives the rate of wind speed exceedances. Finally, using the Poisson assumption, we convert these exceedance rates to annual exceedance probabilities.
Bloemendaal et al. (2022) calculate future risk based on projected climate conditions from 2015 to 2050, following the SSP5-8.5 GHG emission pathway. Because these future SSP5-8.5 estimates cover 2015 and 2050, we assume these conditions correspond to the conditions of 2030. To extend these metrics to SSP5-8.5 2050 and SSP2-4.5 for 2030 and 2050, we linearly interpolate or extrapolate based on radiative forcing (RF). Radiative forcing describes the energy balance at the boundary of the Earth’s atmosphere: higher levels of RF indicate more net radiation entering the atmosphere than being emitted.