Hurricanes Topical Guide

The Associated Press compiled a style guide of essential words, phrases and definitions related to the storm. Terms are from the AP Stylebook and usage in AP stories. This guide omits references to death totals from past hurricanes; those may be added later.

A warm-core tropical cyclone in which the minimum sustained surface wind is 74 mph or more.

Hurricanes are spawned east of the international date line. Typhoons develop west of the line. They are known as cyclones in the Indian Ocean and Australia.

When a hurricane or typhoon loses strength (wind speed), usually after landfall, it is reduced to tropical storm status.

Capitalize hurricane when it is part of the name that weather forecasters assign to a storm: Hurricane Dorian, Hurricane Michael.

Use it and its in pronoun references.

Once storms lose strength and are downgraded to tropical storm or tropical depression status, it may be clearer to simply use the storm's name on first reference: Officials released more water Monday from Houston-area reservoirs overwhelmed by Harvey. Give the storm's current status and history high in the story: Harvey came ashore as a major hurricane and has been downgraded to a tropical storm. After a storm is downgraded, phrasing such as storm Michael or the remnants of Hurricane Maria is also acceptable on first reference, with background later. In broad references to a hurricane and its aftermath: The damage and economic impact from Hurricane Harvey is substantial or the damage and economic impact from Irma is substantial.

Hurricanes are ranked 1 to 5 according to what is known as the Saffir-Simpson Hurricane Wind Scale. Categories 3, 4 and 5 hurricanes are considered major hurricanes.

Category 1 — Winds of 74-95 mph (120-150 kph). Damage primarily to unanchored mobile homes, shrubbery and trees. Some damage to poorly constructed signs and piers. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.

Category 2 — Winds of 96-110 mph (155-175 kph). Some roof, door and window damage to buildings. Considerable damage to mobile homes, small watercraft, trees, poorly constructed signs and piers. 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.

Category 3 — Winds of 111-129 mph (180-210 kph). Some structural damage to small homes. Mobile homes destroyed and large trees blown down. Hurricane Katrina, the costliest natural disaster in U.S. history, was a Category 3 at landfall in 2005 after being a Category 5 in the Gulf of Mexico.

Category 4 — Winds of 130-156 mph (210-250 kph). Wall failures and roof collapses on small homes, and extensive damage to doors and windows. Complete destruction of some homes, especially mobile homes. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months. In 2004, Hurricane Charley hit the Florida Gulf Coast near Fort Myers as a Category 4 storm. It left thousands homeless and the total U.S. damage was estimated at more than $15 billion.

Category 5 — Winds greater than 157 mph (250 kph). Complete roof failure on many homes and industrial buildings. Smaller buildings and mobile homes blown over or completely blown away. Major damage to lower floors of all structures located less than 15 feet (4.5 meters) above sea level and within 500 yards (460 meters) of the shoreline. Massive evacuation of residential areas on low ground within 5 to 10 miles (8 to 16 kilometers) inland may be required.

Hurricane Katrina in 2005, which was a Category 3 storm, was the most expensive hurricane to hit the United States with $160 billion in damage, when adjusted for inflation into 2017 dollars. Hurricane Harvey in 2017 was second with $125 billion in damage, with 2017’s Maria, a Category 4 storm on landfall ranked third at $90 billion. Superstorm Sandy, which pummeled New York and New Jersey in 2012, didn't have the high winds and had lost tropical status by the time it struck. Though not formally called a major hurricane, it had devastating effects and caused $70 billion in damage, when adjusted for inflation.

More than one major hurricane hitting the U.S. in a season is unusual. That happened in 2017, with back-to-back Category 4 hurricanes Harvey and Irma, followed shortly thereafter by Maria, which was Category 5 when it struck Puerto Rico.

Harvey made landfall Aug. 25, 2017, as a Category 4 storm about 30 miles northeast of Corpus Christi, Texas, then lingered just off the Gulf Coast. Harvey dropped 52 inches of rain in the Houston area as a hurricane and then tropical storm, causing catastrophic flooding and an estimated $125 billion in damage.

The Category 5 Hurricane Irma was the most potent Atlantic Ocean hurricane ever, with winds reached 185 mph. Irma was still a Category 5 when it raked Cuba's coast, then a Category 4 storm with 130 mph winds when it slammed into Florida’s Cudjoe Key on Sept. 10.

The names of tropical cyclones are decided by the World Meteorological Organization and are recycled every six years. If more than 21 named tropical cyclones occur in one basin in a season, any additional storms will be named for Greek letters. The names of storms deemed to have caused extraordinary damage are retired from the list. When referring to two hurricanes: hurricanes Maria and Dorian.

The portion of the year that has a relatively high incidence of hurricanes. In the Atlantic, Caribbean and Gulf of Mexico, this is from June through November. In the eastern Pacific, it is May 15 through Nov. 30. In the central Pacific, it is June 1 through Nov. 30.

An announcement that sustained winds of 74 mph (119 km/hr) or higher are expected somewhere within the specified area in association with a tropical, subtropical or post-tropical cyclone. The warning is issued 36 hours before tropical-storm-force winds are expected to arrive.

An announcement that sustained winds of 74 mph (119 km/hr) or higher are possible within the specified area in association with a tropical, subtropical or post-tropical cyclone. A hurricane watch is issued 48 hours in advance of the expected onset of tropical-storm-force winds.

A tropical cyclone in which the maximum sustained surface wind is 38 mph (33 knots) or less.

A warm-core tropical cyclone in which the maximum sustained surface winds range from 39 to 73 mph (34 to 63 knots) inclusive. Capitalize tropical storm when it is part of the name that weather forecasters assign to a storm: Tropical Storm Allison. Do not abbreviate to TS.

Lowercase when referring to the physical shoreline: Atlantic coast, Pacific coast, east coast. Capitalize when referring to regions of the United States lying along such shorelines: the Atlantic Coast states, a Gulf Coast city, the West Coast, the East Coast. Do not capitalize when referring to smaller regions: the Virginia coast. Capitalize the Coast when standing alone only if the reference is to the West Coast.

Damage is destruction: The storm is expected to cause billions of dollars' worth of damage.

Damages are awarded by a court as compensation for injury, loss, etc.: The woman received $25,000 in damages.

FEMA is acceptable on second reference. The FEMA administrator is Peter Gaynor.

Use forecast, not forecasted, for the past tense.

Forecasters at the National Hurricane Center rely on dozens of computer simulations and their own expert experience. They use real-time readings of wind, temperature, air pressure, humidity and more. But those real-time readings are sparse and spread out.

Figuring out a storm's path and strength is tricky and usually forecasts do not go out longer than five days.

Stories about floods usually tell how high the water is and where it is expected to crest. Such a story should also, for comparison, list flood stage and how high the water is above, or below, flood stage. Wrong: The river is expected to crest at 39 feet. Right: The river is expected to crest at 39 feet, 12 feet above flood stage.

But uppercase when used in a title: Good Samaritan Hospital.

A historic event is an important occurrence, one that stands out in history. Any occurrence in the past is a historical event.

Capitalize when referring to U.S. or state-level forces: the National Guard, the Texas National Guard, Texas' National Guard. On second reference, the guard.

When referring to an individual in a National Guard unit, use National Guardsman: He is a National Guardsman.

Lowercase guardsman when it stands alone.

The National Weather Service's National Hurricane Center in Miami has overall responsibility for tracking and providing information about tropical depressions, tropical storms and hurricanes in the Atlantic Ocean, Gulf of Mexico, Caribbean Sea and eastern Pacific Ocean.

The director is Louis Uccellini. On second reference, the NWS or the weather service.

It is measured in inches; use numerals in all references except when beginning a sentence. The verb should conform with rain, not inches: Forecasters said 30 inches of rain is expected to fall.

An abnormal rise of water above the normal tide, generated by a storm.

Superstorm Sandy began as a late-season hurricane in October 2012 but merged with other weather systems and morphed into a massive, extratropical hybrid storm that didn't meet the meteorological definition of a hurricane or tropical storm. It nonetheless retained many characteristics of a hurricane, including a storm surge that swamped much of the New York and New Jersey coasts. It caused $70 billion in damage, when adjusted to 2017 dollars. Either figure makes it, after 2005's Hurricane Katrina and 2017’s hurricanes Harvey and Maria, the fourth-costliest storm of its type in U.S. history. At least 147 people died directly from storm conditions, with many others linked to hypothermia, carbon monoxide poisoning and falling trees during the cleanup effort, according to the National Hurricane Center. Repairs to homes and infrastructure continue today.