The Saffir-Simpson Hurricane Scale

Saffir and Simpson developed a scale for hurricane intensity which can be used to estimate the risk for property damage and coastal flooding.

Wind Speed	Atmospheric Pressure in inches Hg	Surge	Damage Potential	Category
74 - 95 mph	>= 28.94	4 - 5 feet	minimal to mild	1
96 - 110 mph	28.54 - 28.93	6 - 8 feet	moderate	2
111- 130 mph	27.91 - 28.49	9 - 12 feet	extensive	3
131 - 155 mph	27.17 - 27.90	13 - 18 feet	extreme	4
>= 155 mph	<= 27.17	>= 18 feet	catastrophic	5

where:

• 1 knot = 1.15 miles/hour (using statute mile) and 1 km/hr = 0.621 miles/hour

• Storms with wind speeds < 39 miles per hour are termed a tropical depression.

• A tropical storm has wind speeds from 39-73 miles per hour.

The extent of the storm surge is affected by the state of the tides at landfall, with more flooding at high tide than at low tide.

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