Hurricane & Storm Surge Impact

Where could tropical-cyclone hazards create the greatest human and infrastructure impacts?

Data health

Waiting for live sources…

How to read this map

Hazard / signal: Tropical-cyclone / surge hazard
Exposure: People and infrastructure
Consequence / vulnerability: Potential human and access consequences

Official/source values remain distinct from MitchellCo derived screening scores or estimates. Derived values are for prioritization and interpretation, not official warnings or predictions.

Layers

NHC storm forecast pointsClickable official NHC forecast positions. NHC forecast coneOfficial forecast track uncertainty. NHC forecast wind radiiOfficial 34, 50 and 64 kt forecast wind fields. NHC coastal watches/warningsOfficial tropical cyclone coastal segments. NHC storm-surge inundationOfficial potential storm-tide inundation when published. CDC county vulnerabilityShows only counties whose derived impact screen is at or above 55/100. The table and map always use the same set.

clickable NHC forecast point

#rank marker for a qualifying county

34 kt wind field

50 kt

64 kt

storm-surge inundation

Qualifying counties

Above 55/100 threshold—

Waiting for NHC and CDC data.

What this map combines

Hazard: NHC forecast wind fields and coastal products. Exposure: county population. Vulnerability: CDC SVI. The county layer is intentionally screened so the map is not flooded with low-relevance counties.

Derived county wind-impact screen

Non-official score = wind + 15 × SVI
County-center wind term: 0 outside forecast wind radii, 45 inside 34 kt, 65 inside 50 kt, 85 inside 64 kt. Score capped at 100.

Threshold: 55/100. At most eight counties are displayed. Zero qualifying counties is a valid result.

Live status

Forecast points—

Wind polygons—

Warnings—

CDC counties loaded—

NHC: not loaded

Surge: not loaded

SVI: not loaded

Refresh / vintage

NHC tropical layers and surge: every 3 hours. CDC SVI: 2022 vintage, loaded once per selected area. Polling pauses while hidden/offline and backs off after failures.

Sources

NOAA/NWS/NHC Tropical Weather Summary · NHC GIS data · CDC/ATSDR SVI 2022.

NHC attribution: NOAA, National Weather Service, National Hurricane Center and Central Pacific Hurricane Center. Basemaps retain their own attribution.