Storm Hazards & Impacts

Loading…

Where these numbers come from

• Wind — areas reached by tropical-storm-force (39+ mph), 58+ mph and hurricane-force (74+ mph) sustained winds, from the NHC/JTWC best-track wind radii in IBTrACS v04r01, swept along the track exactly as drawn on the track explorer. A county counts if any part of it was inside. Radii are analyzed routinely only since 2004, which is why the list starts then.
• Rain — storm-period totals from PRISM daily 4-km precipitation (PRISM Group, Oregon State University), counting each day's rain only within 500 km of the storm's center (lower 48 states only). Gridded values smooth out the very highest gauge readings.
• Storm surge and inland flooding — high-water marks surveyed after the storm by the USGS Short-Term Network, split by USGS's own label for each mark. Storm surge uses coastal marks (open coast, bays, tidal lakes and tidal rivers, so some sit well inland) and maps the highest water level: surge plus tide, in feet above NAVD88 (roughly mean sea level), which is measured at nearly every coastal mark. Coastal-labeled marks are treated as inland when the water was above 32 ft (no U.S. surge has come close; Katrina's peak was about 28 ft) or when still water stood on ground more than 20 ft above sea level, which is rain or river flooding rather than surge. A county's surge level uses still-water marks; marks USGS flags as wave-affected (pushed higher by waves) are shown faded and used only where a county has nothing else. Inland flooding uses riverine marks and maps how deep the water stood above the ground. Only storms USGS surveyed have marks. Peak storm surge per hurricane landfall from Klotzbach et al. (2026, npj Natural Hazards), using the observed surge database of Needham and Keim (2012) as updated there.
• Deaths, injuries, damage, tornadoes by county — NCEI Storm Events Database: reports tied to the storm (tropical-storm, hurricane and storm-surge reports near the track, plus any report whose narrative names the storm). Reports filed for forecast zones are split evenly across the zone's counties. Damage is as reported at the time (not adjusted for inflation), and is incomplete.
• Direct deaths (storm total, by cause and state) — Muller et al. (2026), Continental United States direct Atlantic tropical cyclone fatalities: 1963–2024, dataset. Atlantic storms, lower 48 states.
• Normalized damage — Mooney et al. (2026) estimate for each continental U.S. hurricane landfall: the damage the storm would cause with today's housing stock, in 2024 dollars (via Klotzbach et al. 2026).
• Power outages — EAGLE-I (U.S. DOE / Oak Ridge National Laboratory; Brelsford et al. 2024, Scientific Data): customers without power in each county every 15 minutes, from November 2014. Peak = highest count (minus the county's routine pre-storm outages) while the storm was over the U.S. or within two days after; share uses EAGLE-I's modeled customer count. EAGLE-I covers most but not all utilities.
• Population — U.S. Census Bureau Vintage 2024 county estimates: today's residents, not those at the time of the storm.
• Backdrops — Topography: Esri World Physical Map (elevation tint and shaded relief). Night lights: NASA GIBS VIIRS Black Marble (2016), city lights seen from space — a guide to where people live, not a population count. Highways: Esri World Street Map. Plain: Esri dark gray canvas.

© 2026 Dan Chavas (Purdue University) · Track & wind-field explorer · Send feedback ·