The Saffir-Simpson Scale

By Cindy Hunsinger

This year has definitely been a busy year at sea with all of the tropical storms and hurricanes. If you watch the weather at all and have kept track of the hurricanes, you may have heard that this storm is a category one or that one is a category five. Now, like me, you may wonder how they measure these storms and when they began using this type of measuring system.

The Saffir-Simpson Scale is the name of the system used to measure these massive and destructive storms. Several decades ago, Herbert Saffir, an engineer and expert in the damage that storms do to buildings, was commissioned by the United Nations to study low-cost housing in hurricane prone areas. He was aware of the usefulness that the Richter scale had in measuring the intensity of earthquakes.

So, after realizing there was no similar way to really describe the effects of a hurricane, he developed his own scale in the late 1960s. In the early part of the 1970s, Robert Simpson, a weather expert and the director of the National Hurricane Center, further expanded on Saffir’s scale to include measurements for flooding and storm surge. This is why the scale used today bears the names of these two men.

There are actually two forms of this scale. One is called the Saffir-Simpson Hurricane scale. This particular scale rates hurricanes from category one to five, in order of increasing intensity. Within each category there are four specific things that meteorologists look for to help them determine how powerful a certain storm will be. These are: barometric pressure, wind damage, storm surge, and damage potential.

With the present scale, a category one storm has winds of 74-95 miles per hour and you can expect to see some damage to trees and to homes that are not securely anchored down. There is also the potential for some mild flooding. In a category two storm, the winds achieve speeds of 96-110 miles per hour, and trees are expected to receive more damage and possible be blown down. There is also the potential of greater damage to unanchored homes.

During a category three storm, the winds will be 111-130 miles per hour. At this point, trees will be blown down, buildings will receive minor structural damage, and there will be more severe flooding. Category four storms have winds of 131-155 miles per hour. These strong storms cause severe damage to the roofs of houses and the coastline will see greater flooding. In a Category Five storm, the winds reach speeds of over 155 miles per hour. At those speeds, major structural damage will occur, small buildings will be swept away, and there will be disastrous flooding.

Higher categories were never added for two reasons. The first is related to the fact that the scale was designed to measure the damage caused by wind, and well, let’s face it, once you get past 156 mph the damage all pretty much looks the same. Therefore creating higher categories seems pointless. The other reason was that at the time the scale was first created, a Category Five storm was almost unheard of.

Today, some scientists feel that the world has changed, and that we will see an increase in higher category storms. So perhaps a new scale is needed. Or the existing scale needs to be extended beyond what Saffir and Simpson ever imagined would be needed.