Here is a look at the 2017 Atlantic hurricane season.
The 2017 Atlantic hurricane season runs from June 1 to November 30. The areas covered include the North Atlantic Ocean, Gulf of Mexico and the Caribbean Sea.
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Oceans and Seas (by name)
The National Weather Service defines a hurricane as "an intense tropical weather system with well-defined circulation and sustained winds of 74 mph (64 knots) or higher."
Hurricanes are rated according to intensity on the Saffir-Simpson Hurricane Wind Scale.
The 1-5 scale estimates potential property damage.
A Category 3 or higher is considered a major hurricane.
The National Hurricane Center advises preparedness:
A hurricane watch indicates the possibility that a region could experience hurricane conditions within 48 hours.
A hurricane warning indicates that sustained winds of at least 74 mph are expected within 36 hours.
April 6, 2017 - The Tropical Meteorology Project from Colorado State University predicts that the "2017 Atlantic basin hurricane season will have slightly below-average activity." They predict a total of 11 named storms and four hurricanes.
May 25, 2017 - The National Oceanic and Atmospheric Administration (NOAA) forecasts a 45% chance for an above-normal season, predicting that there is a 70% chance of having 11 to 17 named storms, of which five to nine could develop into hurricanes, including two to four major hurricanes (categories 3-5).
August 9, 2017 - NOAA raises its forecast prediction to 14 to 19 named tropical systems this year, up from the 11-17 they predicted in a previous outlook released in May. Though NOAA's outlook still calls for five to nine hurricanes, the latest update increases the predicted range of likely major hurricanes by one, from 2-4 to 2-5. NOAA forecasters predict the "season has the potential to be extremely active, and could be the most active since 2010."
Tropical Storm Arlene
April 20, 2017 - Tropical Storm Arlene forms in the central Atlantic Ocean. According to the National Hurricane Center, April tropical storms are rare, and this is only the second one (the first was 2003's Tropical Storm Ana) since the use of satellite.
April 21, 2017 - Arlene moves southwest and south until it dissipates.
Tropical Storm Bret
June 19, 2017 - Tropical Storm Bret forms about 125 miles southeast of Trinidad.
June 20, 2017 - Weakens into a tropical wave.
Tropical Storm Cindy
June 20, 2017 - Tropical Storm Cindy forms in the Gulf of Mexico, about 265 miles south of Morgan City, Louisiana.
June 22, 2017 - Makes landfall just south of Lake Charles, Louisiana. Later weakens to a tropical depression.
Tropical Storm Don
July 17, 2017 - Tropical Storm Don forms about 485 miles east-southeast of Barbados. Weakens to an open wave the next day.
Tropical Storm Emily
July 31, 2017 - Tropical Storm Emily forms near the west coast of Florida and makes landfall on Anna Maria Island. Weakens to a tropical depression after making landfall.
August 6, 2017 - Tropical Storm Franklin forms over the northwestern Caribbean.
August 7, 2017 - Makes landfall on the eastern coast of the Yucatan Peninsula.
August 9, 2017 - Franklin becomes a Category 1 hurricane about 105 miles northeast of Veracruz, Mexico.
August 10, 2017 - Makes landfall in Veracruz, Mexico. Later, Franklin weakens to a tropical storm and then dissipates.
August 13, 2017 - Tropical Storm Gert forms in the Atlantic Ocean.
August 14, 2017 - Gert becomes a hurricane, the second of the season.
August 17, 2017 - Weakens to a post-tropical cyclone.
August 17, 2017 - Tropical Storm Harvey forms about 250 miles east of Barbados.
August 24, 2017 - Harvey strengthens into a hurricane.
August 25, 2017 - Harvey makes landfall between Port Aransas and Port O'Connor, Texas, as a Category 4 storm with winds of 130 mph. Harvey is the first Category 4 hurricane to make landfall in the United States since Hurricane Charley in 2004.
August 26-29, 2017 - Harvey is downgraded to a tropical storm, but stalls over land causing extreme flooding in Texas.
August 30, 2017 - After retreating from the Houston area back to the Gulf of Mexico, Harvey slowly moves northeast and makes a second landfall near Cameron, Louisiana.
-- The death toll from Harvey is at least 82 people. Harvey dumped an estimated 27 trillion gallons of rain over Texas and Louisiana during a six-day period, according to WeatherBell, and also set a record for the most rainfall ever from a tropical cyclone in the continental US, at 51 inches of rain. Estimates put eventual total losses at as much as $75 billion.
August 30, 2017 - Tropical Storm Irma forms 420 miles west of the Cabo Verde Islands.
August 31, 2017 - Irma becomes a hurricane and intensifies into a Category 3 hurricane.
September 4, 2017 - Irma strengthens to a Category 4 hurricane about 490 miles east of the Leeward Islands.
September 5, 2017 - Intensifies into a "potentially catastrophic" Category 5 hurricane as it roars toward the northeastern Caribbean islands.
September 6, 2017 - Hits Antigua, Barbuda St. Martin, Anguilla, St. Kitts and Nevis, US Virgin Islands, British Virgin Islands, causing major damage and devastation to many of the islands.
September 7-8, 2017 - Causes major damage to the Dominican Republic as it passes along the northern coast of Hispaniola. Blasts through Turks and Caicos overnight.
September 8-9, 2017 - Makes landfall in Cuba overnight as a Category 5 storm, with winds of 125 mph. The Bahamas are hit by hurricane-force winds. At least 44 people have died in the Caribbean.
September 10, 2017 - The Florida Keys take a direct hit from Irma as a Category 4 storm. Initial estimates are that 25% of houses on the island chain are destroyed, and 65% have major damage. Irma moves on to hit Marco Island as a Category 3 storm, then travels up the Gulf of Mexico to pummel Naples, Florida.
September 11, 2017 - Irma is downgraded to a tropical storm in north Florida, and to a tropical depression soon after its wind gusts hit Atlanta, causing power outages and downed trees.
-- The death toll from Irma in the US is at least 61 people.
September 5, 2017 - Tropical Storm Jose forms about 1500 miles east of the Lesser Antilles.
September 6, 2017 - Jose strengthens into a hurricane.
September 8, 2017 - Becomes a Category 4 hurricane, east and southeast of the northern Leeward Islands.
September 14, 2017 - Weakens to a tropical storm.
September 15, 2017 - Becomes a hurricane again as it makes its way up the Atlantic, east of the US coast.
September 19, 2017 - Weakens to a tropical storm.
September 6, 2017 - Tropical Storm Katia forms in the southwestern Gulf of Mexico and strengthens into a hurricane the same day.
September 8, 2017 - Makes landfall in eastern Mexico, in the state of Veracruz, as a Category 1 hurricane.
September 9, 2017 - Weakens to a tropical storm as it moves inland in Mexico.
September 16, 2017 - Tropical Storm Lee forms in the eastern Atlantic Ocean, west and southwest of Cabo Verde islands.
September 17, 2017 - Weakens to a tropical depression.
September 22, 2017 - Lee reorganizes and strengthens into a tropical storm, swirling over open water 940 miles east of Bermuda.
September 24, 2017 - Lee becomes a hurricane.
September 27, 2017 - Lee intensifies into a Category 3 hurricane.
September 30, 2017 - Weakens to a tropical storm.
September 16, 2017 - Tropical Storm Maria forms about 620 miles east-southeast of lesser Antilles.
September 17-18, 2017 - Maria rapidly intensifies from a tropical storm into a Category 5 hurricane.
September 18, 2017 - The storm hits the Caribbean island of Dominica as a Category 5 hurricane and devastates the area.
September 20, 2017 - Makes landfall near Yabucoa in Puerto Rico as a Category 4 hurricane. It is the strongest storm to hit Puerto Rico in 85 years. The energy grid is heavily damaged, with an island-wide power outage. Restoring electricity may take months, the governor of Puerto Rico says. The storm also hits the US Virgin Islands, where at least one person dies, likely from drowning.
September 22, 2017 - The National Weather Service orders the evacuation of about 70,000 people living near the Guajataca River in northwest Puerto Rico because a dam is in danger of failing. The storm continues to churn northward, making landfall in the Caribbean islands of Turks and Caicos as a Category 3 hurricane.
September 25, 2017 - Only a few medical centers on the island have working generators and at least three hospitals lack running water. Shortages of medical supplies are reported.
September 26, 2017 - Maria weakens to a tropical storm as it heads northeast out to sea.
December 9, 2017 - The island's Department of Public Safety reports two additional storm-related deaths, increasing the death toll to 64. Investigations by CNN and other news organizations suggest the overall number may be much higher than the official count. In November, funeral directors reported to CNN that at least 499 deaths were believed to be storm-related.
May 29, 2018 - According to an academic report published in the New England Journal of Medicine, an estimated 4,645 people died in Hurricane Maria and its aftermath in Puerto Rico. The article's authors call Puerto Rico's official death toll of 64 a "substantial underestimate." Experts tell CNN it is difficult to say with certainty whether a hurricane "caused" certain deaths.
August 8, 2018 - Puerto Rico admits that the death toll from Hurricane Maria may be far higher than its official estimate of 64. In a report to Congress, the US commonwealth's government says documents show that 1,427 more deaths occurred in the four months after Hurricane Maria than "normal," compared with deaths that occurred the previous four years. The 1,427 figure also appears in a report published July 9.
October 5, 2017 - Tropical Storm Nate forms near the coast of Nicaragua. At least 28 people are killed after Nate passes over Costa Rica, Nicaragua and Honduras. Hundreds are rescued from floodwaters and mudslides. Many lose power and running water.
October 6, 2017 - Nate strengthens into a hurricane about 95 miles west-northwest from the western tip of Cuba.
October 7, 2017 - Hurricane Nate makes US landfall as a Category 1 storm near the mouth of the Mississippi River in southeast Louisiana.
October 8, 2017 - Nate makes its second and final US landfall early in the morning as a Category 1 hurricane near Biloxi, Mississippi, and is later downgraded to a tropical depression.
October 9, 2017 - Tropical Storm Ophelia forms in the Atlantic Ocean.
October 11, 2017 - Strengthens to a hurricane.
October 14, 2017 - Hurricane Ophelia strengthens into a Category 3 storm about 220 miles south of the Azores. Ophelia is the farthest east that a major hurricane has ever been in the Atlantic. The previous record was held by Frances in 1980, according to CNN Meteorologist Haley Brink.
October 15, 2017 - Ophelia weakens from a Category 3 to a Category 1 hurricane throughout the day.
October 16, 2017 - Ophelia makes landfall as a post-tropical storm in Ireland. Three deaths are attributed to the storm.
Tropical Storm Philippe
October 28, 2017 - Tropical Storm Philippe forms in the Atlantic Ocean. It dissipates the following day.
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