Saffir-Simpson Hurricane Wind Scale
Introduction
The Saffir-Simpson Hurricane Wind Scale (SSHWS) is a 1 to 5 categorization based on the maximum sustained wind speed of a hurricane. This scale is used to estimate potential property damage and flooding along the coast from a hurricane landfall. The scale was developed in the early 1970s by engineer Herbert Saffir and meteorologist Robert Simpson, who was then the director of the National Hurricane Center (NHC).
History
The SSHWS was introduced in 1971 by Herbert Saffir, a civil engineer, and Robert Simpson, then director of the NHC. Initially, the scale included central pressure and storm surge as criteria, but these were later removed to focus solely on wind speed. The scale was adopted by the NHC in 1973 and has since been used to communicate the potential impact of hurricanes to the public and emergency management officials.
Scale Categories
The Saffir-Simpson Hurricane Wind Scale categorizes hurricanes into five distinct categories based on their sustained wind speeds. Each category represents a range of wind speeds and potential damage.
Category 1
- **Wind Speed:** 74-95 mph (119-153 km/h)
- **Damage Potential:** Minimal damage to unanchored mobile homes, trees, and shrubbery. Some coastal flooding and minor pier damage.
Category 2
- **Wind Speed:** 96-110 mph (154-177 km/h)
- **Damage Potential:** Considerable damage to mobile homes, trees, and shrubbery. Some roofing material, door, and window damage. Coastal flooding and significant pier damage.
Category 3
- **Wind Speed:** 111-129 mph (178-208 km/h)
- **Damage Potential:** Devastating damage to small residences and utility buildings. Large trees uprooted, and extensive coastal flooding. Mobile homes are often destroyed.
Category 4
- **Wind Speed:** 130-156 mph (209-251 km/h)
- **Damage Potential:** Catastrophic damage to residences and industrial buildings. Most trees snapped or uprooted. Power outages lasting weeks to months. Coastal areas inundated with water.
Category 5
- **Wind Speed:** 157 mph or higher (252 km/h or higher)
- **Damage Potential:** Complete roof failure on many residences and industrial buildings. High percentage of frame homes destroyed. Total collapse of many buildings. Inundation of coastal areas causing massive evacuation.
Methodology
The SSHWS relies on the measurement of maximum sustained winds, which are defined as the highest average wind speed over a one-minute period at a height of 10 meters above the surface. These measurements are typically obtained through reconnaissance aircraft, satellite data, and surface observations.
Applications
The SSHWS is primarily used by meteorologists and emergency management officials to communicate the potential impact of hurricanes to the public. It helps in the planning and execution of evacuation orders, resource allocation, and disaster response strategies. The scale also aids in the design and construction of buildings to withstand specific wind speeds.
Criticisms and Limitations
While the SSHWS is widely used, it has faced criticism for its focus solely on wind speed, ignoring other factors like storm surge and rainfall, which can also cause significant damage. Some experts argue for a more comprehensive scale that includes these elements to provide a fuller picture of a hurricane's potential impact.
Future Developments
Ongoing research aims to improve the accuracy and comprehensiveness of hurricane impact assessments. Advances in technology, such as improved satellite imagery and computer modeling, are expected to enhance the predictive capabilities of the SSHWS and potentially lead to the development of a more inclusive scale.