Just as earthquakes are rated using the Richter scale, hurricanes are rated with the Saffir-Simpson scale. The Saffir-Simpson scale is the standard scale for rating both the severity of hurricanes and the damage they cause. Developed in the early 1970s by National Hurricane Center directors Robert Simpson and Herbert Saffir, this scale rates hurricanes from category one (1) (i.e., the least intense) to category five (5) (i.e., the most intense). Each category measures the range of conditions using four basic criteria: barometric pressure, wind speed, storm surge, and damage potential.
Your assignment: A hurricane has blown into the North Carolina coast. You must identify how severe the storm is so that you may order an evacuation. Can you assign it a Saffir-Simpson scale number in time to decide whether or not to evacuate? Let's find out.
|
 |
- The following table identifies the criteria used for each category. Familiarize yourself with this table.
- Read the description of the hurricane threatening the North Carolina coast.
- Based on the description, assign the hurricane a rating according to the criteria of the scale.
Category |
Barometric
Pressure |
Wind Speed |
Storm Surge |
Damage Potential |
1
"minimal" |
<980 mb |
74-95 mph
64-82 knots |
3-5 ft |
Some damage to shrubs, trees, and unanchored mobile homes; some flooding of low-lying coastal roads. |
2
"moderate" |
981-965 mb |
96-110 mph
83-95 knots |
6-8 ft |
Considerable damage to shrubs, with some trees blown down; extensive damage to mobile homes, and inundation by rising water of coast roads and low-lying escape routes. |
3
"extensive" |
964-945 mb |
111-130 mph
96-113 knots |
9-12 ft |
Large trees blown down, some structural damage to small buildings, destruction of mobile homes, and flooding of sea-level coastland 8 miles or more inland; requires evacuation of low-lying residences near the shoreline. |
4
"extreme" |
944-920 mb |
131-155 mph
114-135 knots |
13-18 ft |
Severe damage to roofing materials, windows, and doors; complete destruction of mobile homes, flooding of low-lying areas as much as 6 miles inland, and major damage to structures near shore due to battering by waves and floating debris. |
5
"catastrophic" |
< 920 mb |
>155 mph
135 knots |
>18 ft |
Complete failure of roofs on residences and industrial buildings, the overturning or sweeping away of small buildings, and major damage to structures less than 15 feet above sea level within 1,500 feet of shore; requires evacuation of all residential areas on low-lying ground within 5-10 miles of shore. |
Hurricane Description: A hurricane has made landfall on the North Carolina coast near Cape Fear, NC. In addition to sustained winds of 115 mph, the storm surge and high water come to 12 feet in some coastal areas. Heavy rains create extensive inland flooding from the Carolinas into Virginia, West Virginia and Pennsylvania. Strong inland winds create severe damage and power outages with hurricane-force wind gusts extending to Raleigh, NC. Large trees that are blown down. damaging structures and cars, and the hurricane's winds destroy mobile homes and damage several small buildings.
The hurricane's 12-foot storm surge carry away a temporary North Topsail Beach police station and town hall, housed in a doublewide trailer. Extensive flooding struck the coastline of Wrightsville Beach, several miles from the coast of Cape Fear. Nearly a half-million tourists and residents are evacuated from the coasts of North and South Carolina, especially those in low-lying areas.
|
|
