Hurricane Basics & History
First In the 2015 Series
"Hurricanes cause devastating and sometimes deadly damage, with violent winds and heavy rains destroying buildings, inundating both coastal and inland areas, and displacing residents from their communities. Each year, we call attention to the risks hurricanes and tropical storms pose, as well as the steps we can take to protect ourselves, our loved ones, and our communities. During National Hurricane Preparedness Week, we recommit to strengthening the capacity of local responders and creating resilient cities, towns, and neighborhoods that are prepared when disaster strikes." - President Obama
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| Looking for past or current hurricanes? Click Image or Here |
President Obama declared May 24 - May 30 “National Hurricane Preparedness Week." FEMA, along with the National Oceanic and Atmospheric Administration (NOAA), is helping to raise awareness of steps that can be taken to help protect citizens, and their communities and property.
What is a Hurricane?
A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface. Tropical cyclones are classified as follows:
| * Sustained winds A 1-minute average wind measured at about 33 ft (10 meters) above the surface. ** 1 knot = 1 nautical mile per hour or 1.15 statute miles per hour. Abbreviated as "kt". |
Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds* of 38 mph (33 kt**) or less
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds* of 38 mph (33 kt**) or less
Tropical Storm
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-63 kt)
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-63 kt)
Hurricane
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 kt) or higher
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 kt) or higher
Familiarize yourself with the terms that are used to identify a hurricane.
- A hurricane watch means a hurricane is possible in your area. Be prepared to evacuate. Monitor local radio and television news outlets or listen to NOAA Weather Radio for the latest developments.
- A hurricane warning is when a hurricane is expected in your area. If local authorities advise you to evacuate, leave immediately.
Hurricanes are classified into five categories based on their wind speed, central pressure, and damage potential. Category Three and higher hurricanes are considered major hurricanes, though Categories One and Two are still extremely dangerous and warrant your full attention.The following chart details the categories and the damage that can result from a storm with that strength.
Saffir-Simpson Hurricane Scale
Saffir-Simpson Hurricane Scale for Kids (NASA)
| Scale Number (Category) | Sustained Winds | Damage | Storm Surge |
|---|---|---|---|
| 74-95 mph 64-82 kt 119-153 km/h | Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days. | 4-5 feet | |
| 96-110 mph 83-95 kt 154-177 km/h | Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks. | 6-8 feet | |
| 111-129 mph 96-112 kt 178-208 km/h | Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes. | 9-12 feet | |
| 130-156 mph 113-136 kt 209-251 km/h | Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months. | 13-18 feet | |
| 157 mph or higher 137 kt or higher 252 km/h or higher | Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months. | Greater than 18 feet |
Hurricane History
In the following article, we look at the 2014 Hurricane season in review, comparing the forecast to actual results. We also look at NOAA and Colorado State University forecasts for the 2014 Season.
