the Saffir-Simpson Hurricane wind scale 5 categories damage incurred is wind speed the real killer?

The strength of Hurricane Patricia during the 2015 season increased to a wind speed of 213 miles per hour for a short period, designating it the second most powerful hurricane ever recorded. Three factors combined to cause this power surge, Warm water, unusually deep warm water, and low-density water from rivers entering the ocean which acted to stabilize the water column causing the storm to gain power. When Patricia made landfall near Cuizmala, Jalisco, Mexico the windspeed was drastically reduced to 150 miles per hour, a strong Category 4 storm.

Hurricane Patricia, the second most powerful Hurricane on record.

The intensity of a hurricane is determined by many factors, however, two Storm Surge and Wind Speed are those we as a layman are most accustomed to. As the Hurricanes form off of the Western Coast of Africa the initial information we generally receive is the wind speed, people have a tendency to remember the first bit of reporting heard. There was for years a correlation between wind and storm surge, the stronger the wind the more intense the storm surge. It worked well for years however they are actually two different and separate parts of the storm. Storm Surge is the cause of flooding, and most fatalities, the storm surge predictions normally come after the wind speed reports, which determines the Hurricanes category. Likewise, the scale does not address flooding caused by intense rainfall, or the Tornadoes that form on the outskirts of the storm.

(Follow this Link to Saffir-Simpson Hurricane Wind Scale, the National Weather Service.)

The Categories are determined by the wind speed and designated by the Saffir-Simpson Hurricane wind scale. Composed of 5 categories it classifies the storms as they increase or decrease in wind intensity, from 74 miles per hour, (the lowest wind speed of a Hurricane) to 157 or higher miles per hour (classifying as the highest Hurricane wind speed.) In this blog, I will explain the 5 categories detailing the damage incurred when they make landfall. The wind speed changes many times, a category 4 may be reduced to a 2 as it nears the shoreline, and once making landfall it may become low enough to no longer be classified as a Hurricane. That is when the storm surge, Tornadoes, and rainfall make their devastating appearance causing more damage and deaths than the Hurricane itself. The unsettled weather continues long after the storm passes working it's way North then eventually dissipating into heavy rainfall. Filling reservoirs, flowing down mountains causing creeks and rivers to go over their banks eventually inundating towns bordering the river banks. As the water rises in the reservoir the pressure may compromise the dams and if water is not released it may be breached. Wind speed does an OK job of predicting flooding, rain, and Tornadoes, but not the lingering effects and longevity of the three factors. Perhaps wind speed (Catagories) should not be used as the Hurricane approaches shore instead more relying on storm surge predictions.

The first bit of information we hear is what most people remember, it is called an "Anchoring" of information. We don't forget it and in turn, it makes us rely on the Saffir-Simpson Hurricane wind scale, (Catagories) for the duration of the event. It makes sense, nearly everyone is able to relate wind speed with resulting damage sustained, further building experience re-enforcing our anchor information, causing us to ignore the oncoming deluge caused by the Storm Surge. Let's get into the Catagories, wind speed and the damage capable of being caused by it.

Category 1) Winds are sustained at 74-95 miles per hour, 64-82 knots, or 119-153 kilometers per hour. Airborne debris striking people, livestock, and pets may cause death or serious injury. Older mobile homes may be destroyed, those constructed prior to 1994, those with weak or no foundations could be knocked off of their foundations. Newer mobile homes that are installed properly with adequate anchoring may suffer carport, patio enclosure, and sunroom damage. Wood frame houses that are not constructed properly may experience severe damage such as porch covering, awnings, and outbuilding damage. Windows are always at risk from being shattered by the flying debris, masonry chimneys may be toppled over. Even state of the art constructed frame homes may suffer roof shingles torn off, siding, soffit and gutter problems. Apartment buildings and store roof coverings could be partially ripped apart or removed. Industrial buildings can suffer damage to roofing being partially removed by the wind. Windows in high-rise buildings may be broken by the flying pieces of other buildings smashing into them. The broken glass may hang into the window frames for an extended period after the storm, making the areas below extremely dangerous and unusable until the glass is removed. Some commercial signs, fencing, and canopies may be destroyed. Trees with shallow root systems may fall over, causing roadways to be blocked. Utilities will be compromised causing outages that may extend for a few days to as long as several weeks.

Category 3 Hurricane illustration.

Category 2)  Winds are a constant 96-110 mph, 83-95 kt, or 154-177 km/h), extremely high winds capable of extensive damage. Parts of destroyed structures carried in the high winds have the potential of causing serious injury or death to farm animals, our pets, and ourselves. Buildings will have falling debris. Older mobile homes will be destroyed ejecting sheet siding and metal parts capable of shredding other mobile homes in their vicinity, newer mobiles homes may also be destroyed. The roofs of shoddily built frame homes if not anchored properly have a high incidence of the roof being completely blown away, adding to the flying stuff in the wind. Window breakage is high, as well as major roof and siding being ripped off into the flying tangle of wind carried construction materials. All aluminum screen porches, covers, and enclosures will be widespread. Apartment and Industrial buildings will suffer will experience a high incidence of roof and siding damage, some un-reinforced brick walls will collapse. Glass broken in tall buildings will pose a problem long after the storm, hanging in frames it will continue to fall until it is manually removed, until then the area must be avoided. Trees with shallow rain-soaked root areas will topple over, some will snap into pieces, be uprooted, and fall into roads blocking them, that will be widespread. Power outages lasting several days to weeks will be the norm, a common occurrence resulting from natural disasters. Potable water will become scarce as the processing plants are shut down due to filtration system failures and the power interruptions.

Category 3) Sustained winds 111-129 mph, 96-112 kt, or 178-208 km/h, high winds causing devastating damage. Presenting a high risk of injury or death to livestock, pets, and humans because of the flying and falling refuse torn loose by the wind. Newer mobile homes will have severe damage including complete roof failure and possible walls failing. After the wind blows the roofs and exterior walls off of poorly built frame homes causing complete collapse, as will the windows. Gable ends and roofs may sustain major damage on well-built frame houses, patios will experience extensive damage as well. A large percentage of damage will occur to the roofing and siding on apartment buildings and other commercial establishments, again with hanging broken glass in frames and the shattered remains flying throughout the area. Structural damage to framing made of steel or wood will be isolated but start to appear at these wind speeds. Brick and mortar buildings that are not re-enforced will collapse, older metal buildings will meet the identical fate. Most commercial signs, fences, and covers will be completely blown apart. Many trees will be toppled over, crashing into houses, blocking roads, and destroying vehicles. Utilities will be non-existent for several days to weeks on end, continuing to be an issue long after the storm passes through.

Category 4) Steady winds 130-156 mph, 113-136 kt, or 209-251 km/h, this velocity of wind cause catastrophic damage. Death and severe injuries to livestock, pets, and humans from airborne and falling pieces torn from structures are common and widespread. New mobile homes will be destroyed, all older pre-1994 mobile homes will be total loses as well as poorly constructed frame houses. Newer well-built homes will suffer severe loss of roofs and some exterior walls, doors, windows, and outbuildings. The wind carried debris will destroy all exposed glass and penetrate the inside spaces, the falling glass broke free from high above will pose a threat until it is removed and disposed of. Apartment buildings will experience a high degree of damage to the upper floors, structural damage will occur to the top floors. Masonry buildings that are not reinforced will be destroyed as will older Steel framed buildings resulting in complete failure of the structure. Most windows in high rise buildings will be blown out, the threat of falling glass will remain long after the wind stops. Most trees will be blown over or snapped into pieces, power poles will suffer the same fate. Electrical outages will isolate the area affected, lingering on for weeks, water will be impacted also due to processing plant damage, lack of electrical power and failed filtering systems. Most of the area will not be able to be habituated for months, the human suffering will be intense. Relief centers for long-term occupancy will be established, food resources will be scarce it will all have to be trucked in. Employment will be slow to recover, clean up will be the normal everyday activity.

Hurricane Andrew, Category 5 complete destructive damage.

Category 5) Extreme constant winds 157 mph or higher, 137 kt or higher, or 252 km/h Catastrophic wind speed causing devastating damage. The risk of severe injury and death is elevated to an extremely high risk is certain when struck from falling or wind-driven debris, no matter if struck while inside a mobile or frame house or outdoors. Complete destruction of all mobile homes will occur, the age does not matter. Frame homes will be destroyed in huge numbers, total wall collapse, and roofs torn away will be common. Doors, windows, outbuildings, and freestanding vehicles will all be lost to the wind, huge amounts of destroyed structures, vehicles, trees, and signage will be aloft in the wind. Nearly all windows will be shattered by either the wind, debris, or a combination of the two. Wood roofed commercial buildings will suffer devastating damage because of the roofs being blown apart. Masonry walls will collapse, un-enforced masonry buildings will be totally destroyed, as will older steel buildings. A high percentage of the apartment and commercial buildings will meet their final minutes as well. All windows will be broken adding to the flying mess of life-threatening missiles. Commercial signs, fences, and outbuildings will all be total loses. All trees will be broken or blown over along with power poles and lines. Residential blocks will be isolated, cell phone service will be non-existent, water and power outages will take months to restore, long-term water shortages will rule the weeks and months following the event. The human suffering will be the defining factor, the entire area will be uninhabitable for many weeks and months. Employment will be slow to return, however cleanup efforts will keep everyone busy for months.

This is a lot of wind, even a Category 1 storm has strong winds that are extremely destructive, they are not to be messed with. Meteorologist cringe when the storm surge is ignored and Hurricanes are referred to as being "just" a Catagory 1 or 2, some residents consider Hurricanes to not be a threat unless they exceed Category 3. Personally, I would leave Dodge at the hint of a Catagory 1, I would chirp "cluck cluck cluck" (chicken talk) all the way out of town. I have not in this blog taken into account the storm surge, flooding, rain, and destroyed water wells. The wind Catagories are terrible but the real damage happens when the breeze stops and the water flow continues.

(Follow this Link to NOAA Storm Surge Overview paper.)

Thanks for reading and sharing my blog, I have not been in a full blown Hurricane, I have experienced the aftermath while in Memphis, suffering a deep cut in the thigh by a shattered window. I was also in an 80 mph wind storm while living here on the California Delta, it blew our dock apart and nearly destroyed a 50-foot boat that was stored for a person. these are a strong wind and deserve our respect. Realizing just how powerful the wind is adds to our overall self-awareness of our environment, what to expect from them and the preparations we can partake in prior to the event. Wind storms happen everywhere, they don't have to be classified in a Catagory or labled a Hurricane to be a threat to us, they merely have to blow hard. Thanks again, leave a comment about your experiences with the extreme wind, or a Hurricane.

jacquesandkate  EmergencyKitsPlus.com