For more information, visit the Wikipedia Saffir-Simpson Hurricane Scale article.
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The 'Saffir–Simpson Hurricane Scale (SSHS), or the Saffir–Simpson Hurricane Wind Scale (SSHWS), classifies hurricanes, Atlantic and Eastern Pacific tropical cyclones that exceed the intensities of tropical depressions and tropical storms (the weakest two tropical cyclone categories in the Atlantic and Pacific), into five categories distinguished by the intensities of their sustained winds. To be classified as a hurricane, a tropical cyclone must have maximum sustained winds of at least 74 mph (64 knots; 119 km/h; 33 m/s). The highest classification in the scale, Category 5, is reserved for storms with winds above 156 mph (136 knots; 251 km/h; 70 m/s). These five classifications can provide some indication of the potential damage and flooding a hurricane can cause upon its landfall.
Officially, the SSHS is used only to describe hurricanes forming in the Atlantic Ocean and northern Pacific Ocean east of the International Date Line. Other areas use different scales to label these storms, which, depending on the area, are called cyclones or typhoons.
There is occasional criticism of the classifications as being too simple; they do not take into account rain, storm surge, and other important factors. However, defenders claim the SSHS is meant to be straightforward.
|<39 mph(<62 km/h)||1012-1028 mbar|
|<33 knots(<57 feet/sec)||29.88-30.35|
A tropical depression is the first/second(depends on source) stage in devlopment. It has winds of ≤38 mph and a pressure usually of 1012-1028 mbar. The storm can stay at this status or strengthened to a well named storm.
- Main article: Category 1
|Sustained winds||33–42 m/s||64–82 kn|
Hurricane Humberto(2013) At Peak Intensity.
|119–153 km/h||74–95 mph|
|Normal central pressure, with exceptions||980–994 mbar||28.94 inHg|
Very dangerous winds will produce some damage
Category 1 storms usually cause no significant structural damage to most well-constructed permanent structures; however, they can topple unanchored mobile homes, as well as uproot or snap numerous trees. Poorly attached roof shingles or tiles can blow off. Coastal flooding and pier damage are often associated with Category 1 storms. Power outages are typically widespread to extensive, sometimes lasting several days. Even though it is the least intense type of hurricane, the storm can still produce widespread damage and can be a life-threatening storm.
- Main article: Category 2
|Sustained winds||43–49 m/s||83–95 kn|
Gordon near peak intensity.
|154–177 km/h||96–110 mph|
|Normal central pressure||965–979 mbar||28.50–28.91 inHg|
Extremely dangerous winds will cause extensive damage
Storms of Category 2 intensity often damage roofing material (sometimes exposing the roof) and inflict damage upon poorly constructed doors and windows. Poorly constructed signs and piers can receive considerable damage and many trees are uprooted or snapped. Mobile homes, whether anchored or not, are typically damaged and sometimes destroyed, and many manufactured homes also suffer structural damage. Small craft in unprotected anchorages may break their moorings. Extensive to near-total power outages and scattered loss of potable water are likely, possibly lasting many days.
Main Articles: Category 3 and Major Hurricane
|Sustained winds||50–58 m/s||96–112 kn|
Sandy near peak.
|178–208 km/h||111–129 mph|
|Normal central pressure||945–964 mbar||27.91–28.47 inHg|
Devastating damage will occur.
Tropical cyclones of Category 3 and higher are described as major hurricanes in the Atlantic or Eastern Pacific basins. These storms can cause some structural damage to small residences and utility buildings, particularly those of wood frame or manufactured materials with minor curtainwall failures. Buildings that lack a solid foundation, such as mobile homes, are usually destroyed, and gable-end roofs are peeled off. Manufactured homes usually sustain severe and irreparable damage. Flooding near the coast destroys smaller structures, while larger structures are struck by floating debris. A large number of trees are uprooted or snapped, isolating many areas. Additionally, terrain may be flooded well inland. Near-total to total power loss is likely for up to several weeks and water will likely also be lost.
- Main article: Category 4
|Sustained winds||58–70 m/s||113–136 kn|| |
Igor near peak intensity.
|209–251 km/h||130–156 mph|
|Normal central pressure||920–944 mbar||27.17–27.88 inHg|
Catastrophic damage will occur.
Category 4 hurricanes tend to produce more extensive curtainwall failures, with some complete structural failure on small residences. Heavy, irreparable damage and near complete destruction of gas station canopies and other wide span overhang type structures are common. Mobile and manufactured homes are often flattened. Most trees, except for the heartiest, are uprooted or snapped, isolating many areas. These storms cause extensive beach erosion, while terrain may be flooded far inland. Total and long-lived electrical and water losses are to be expected, possibly for many weeks.
The Galveston Hurricane of 1900, the deadliest natural disaster to hit the United States, peaked at an intensity that corresponds to a modern-day Category 4 storm. Other examples of storms making landfall at this intensity include Hazel (1954), Audrey (1957), Flora (1963), Cleo (1964), Frederic (1979), Joan (1988), Iniki (1992), Luis (1995), Lenny (1999), Charley (2004), and Dennis (2005).
- Main article: Category 5
|Sustained winds||≥ 70 m/s||≥ 137 kn|| |
Katrina at peak intensity
|≥ 252 km/h||≥157 mph|
|Normal central pressure||< 920 mbar||< 27.17 inHg|
Unimaginable damage will occur.
Category 5 is the highest category a tropical cyclone can obtain on the SSHS. These storms cause complete roof failure on all residences and industrial buildings in the area, and complete building failures with any kind of utility buildings blown over or away. Collapse of all wide-span roofs and walls in the area, especially those with no interior supports, is common. Very heavy and damage beyond the limitations of our imaginations to many wood frame structures and total destruction to mobile/manufactured homes is prevalent. Only a couple types of structures are capable of surviving intact, and only if located at least three to five miles (five to eight kilometres) inland. They include office, condominium and apartment buildings and hotels that are of ultra solid concrete or ultimate steel frame construction, public multi-story concrete parking garages, and residences that are made of either ultima reinforced brick or super concrete/invincible cement block and have extremely hipped roofs with slopes of no less than 35 degrees from horizontal and no overhangs of any kind, and if the windows are either made of the best hurricane-resistant safety glass or covered with extra safe shutters. Unless all of these requirements are met, the violent weather demolition of a structure is certain.
The storm's extreme flooding causes unspeakable damage to the lower floors of all structures near the shoreline, and many coastal structures can be completely flattened or washed to sea by the storm surge. Virtually all trees are uprooted, torn apart, snapped, and some may be debarked, isolating most communities impacted. Massive evacuations of residential areas may be required if the hurricane threatens populated areas. Total and unimaginably long-lived extensive power outages and extreme water losses are to be expected, possibly for up to several days, and even weeks.
Historical examples of storms that made landfall at Category 5 status include the Labor Day Hurricane of 1935, Janet (1955), the 1959 Mexico Hurricane, Anita (1977), David (1979), Gilbert (1988), Andrew (1992), Dean and Felix (both in 2007), and Haiyan (2013), which was among the strongest landfalling cyclones ever. It made landfall over the Philippines on November 7, 2013 at peak intensity with 195 mph winds and an air pressure of 895 millibars.