Tropical cyclones rotate counterclockwise in the Northern Hemisphere. They are classified as follows: Tropical Depression: A tropical cyclone with maximum sustained winds of 38 mph 33 knots or less. Tropical Storm: A tropical cyclone with maximum sustained winds of 39 to 73 mph 34 to 63 knots.
Hurricane: A tropical cyclone with maximum sustained winds of 74 mph 64 knots or higher. In the western North Pacific, hurricanes are called typhoons; similar storms in the Indian Ocean and South Pacific Ocean are called cyclones. Major Hurricane: A tropical cyclone with maximum sustained winds of mph 96 knots or higher, corresponding to a Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale.
Tropical cyclones forming between 5 and 30 degrees North latitude typically move toward the west. Sometimes the winds in the middle and upper levels of the atmosphere change and steer the cyclone toward the north and northwest. When tropical cyclones reach latitudes near 30 degrees North, they often move northeast. The Atlantic hurricane season runs from June 1 to November Based on a year climate period from to , an average Atlantic hurricane season has 14 named storms, 7 hurricanes, and 3 major hurricanes Category 3, 4, or 5 on the Saffir-Simpson Hurricane Wind Scale.
The first named storm typically forms in mid to late June, the first hurricane tends to form in early to mid-August, and the first major hurricane forms in late August or early September.
The eastern Pacific hurricane season runs from May 15 to November Based on a year climate period from to , an average eastern Pacific hurricane season has 15 named storms, 8 hurricanes, and 4 major hurricanes. The first named storm typically forms in early to mid-June, the first hurricane tends to form in late June, and the first major hurricane forms in mid-July.
The following tables describe the progress of typical hurricane seasons in the Atlantic and eastern Pacific basins by showing benchmark dates when a given number of named storms, hurricanes, and major hurricanes typically forms. It is important to note, however, that formation dates in individual hurricane seasons could vary considerably from these average dates.
Sally brought post-tropical conditions to Georgia, the Carolinas and southern Virginia. Sally caused four direct deaths in the United States. By September 23 Teddy brought destructive waves, strong wind and heavy rainfall to Atlantic Canada and made landfall in Nova Scotia. Teddy caused three direct deaths in the United States. Teddy became a Category 4 hurricane on September 17 in the Western Atlantic. The hurricane turned northwestward and passed east of Bermuda as a Category 1 storm and continued north to Nova Scotia, becoming a Category 2 storm.
Tropical storm Vicky also developed on September 14, west of the Cabo Verde Islands and dissipated a few days later. Wilfred became a tropical storm on September 18 in the eastern tropical Atlantic and did not threaten land before degenerating on September Tropical Storm Beta formed on September 18 in the Gulf of Mexico and brought tropical storm conditions to the southeastern coast of Texas on September 21 and made landfall there on September The storm stalled inland in Texas before moving northeastward and deteriorating to a tropical depression.
Beta dropped up to 20 inches of rain in parts of Texas, including about 14 inches in the Houston metropolitan area, and continued to bring heavy rain to Louisiana, Mississippi and Tennessee.
Philip Klotzbach it was the 9th named storm to make landfall in the continental United States, tying the record set in , and only the second time a letter from the Greek alphabet has had to be used by U. Beta caused one direct death in the United States. Hurricane Delta, the earliest 25 th named storm on record, formed on October 5 in the Caribbean Sea near Jamaica and became the ninth hurricane of later that day.
Delta rapidly intensified near the Yucatan Peninsula to Category 4 strength and made landfall there on October 7 as a Category 2 storm. Delta moved into the southern Gulf of Mexico and strengthened to a Category 3 storm on October 8. Delta brought hurricane conditions to southwest and central Louisiana and eastern Texas before moving northeastward through Arkansas, Mississippi, and Alabama and the Tennessee valley as a tropical storm and later affecting the Mid-Atlantic states.
Insurers have closed 93 percent of all claims reported in Louisiana. Delta caused two direct deaths in the United States. Hurricane Epsilon became a hurricane on October 20 and reached Category 3 status on October Epsilon caused one direct death in the United States.
Hurricane Zeta became a hurricane on October 26 and made landfall on the Yucatan Peninsula of Mexico. Zeta made landfall on October 28 as a Category 3 hurricane near Cocodrie, Louisiana and was the record-breaking fifth named storm to strike Louisiana in one season. Zeta brought storm surge, high winds and heavy rain to southeastern Louisiana and southern Mississippi and continued through the southeastern states with damaging winds and heavy rainfall.
Zeta left about 2. Louisiana Gov. John Bel Edwards said the hurricane caused catastrophic damage on Grand Isle in Jefferson Parish by causing three breaches in a levee. On November 3 slow-moving Eta made landfall in Nicaragua as a Category 4 storm, bringing catastrophic wind damage, flash flooding, storm surge and landslides. Eta deteriorated over Honduras on its way to the north Caribbean Sea, but regained tropical storm strength and made landfall in Cuba on November 8.
The storm turned northwestward and made landfall in Lower Matecumbe Key, Florida on November 8 as a strong tropical storm and continued to the southwest coast of Florida, bringing heavy rainfall, flash flooding and wind. Eta traveled into the Gulf of Mexico and regained hurricane status on November 11 offshore of southwestern Florida bringing heavy squalls with tropical-storm force winds.
On November 12 Eta made a second landfall in Florida near Cedar Key as a tropical storm, producing dangerous storm surge, heavy rains and gusty winds along the Florida Gulf Coast and the northern Florida Peninsula. Eta passed offshore of the coasts of South and North Carolina before dissipating. Eta caused seven direct deaths in the United States.
On November 10, a record-breaking 29 th named storm—Theta—formed in the northeast Atlantic Ocean. Theta did not threaten land. Hurricane Iota, the 30 th named storm of the hurricane season, formed on November 13 in the central Caribbean Sea and became a hurricane on November Iota became a major hurricane and strengthened to Category 5 status on its way to Central America, and was the strongest hurricane of the hurricane season. Iota brought catastrophic winds, life-threatening storm surge and extreme rainfall to Nicaragua and Honduras.
Iota moved west across Honduras and dissipated over El Salvador. By mid-day July 26 Douglas was closing in on the island of Maui as a Category 1 hurricane. Douglas passed to the north of the islands of Maui, Oahu and Kauai, producing large swells, damaging surf, strong damaging winds.
Rainfall between three and six inches but possibly more fell on the islands. Barry became a hurricane on July 13 in the Gulf of Mexico as it moved toward the Louisiana coast. It made landfall later that day near Intracoastal City, Louisiana, as a tropical storm, bringing heavy rain and wind to the north central Gulf Coast, and remained over Louisiana as it weakened into a tropical depression on July Other areas impacted were the Mississippi River Valley and the southeastern states of Alabama, Florida and Mississippi.
Dorian became a hurricane on August 28 near St. Thomas, U. Virgin Islands. Dorian continued to pound the Bahamas into September 3 with devastating wind, rain and storm surge. Dorian brought storm surge resulting in beach erosion and flooding to east coast Florida as a Category 3 storm, and later affected South and North Carolina. It made landfall over Nova Scotia on September 7 as a Category 1 hurricane. Hurricanes are tropical cyclones. According to the Saffir-Simpson scale , here are the sustained winds linked to categories 2 through 5 hurricanes:.
At heart, hurricanes are fueled by just two ingredients: heat and water. Hurricanes are seeded over the warm waters above the equator, where the air above the ocean's surface takes in heat and moisture. As the hot air rises, it leaves a lower pressure region below it. This process repeats as air from higher pressure areas moves into the lower pressure area, heats up, and rises, in turn, producing swirls in the air, according to NASA.
Once this hot air gets high enough into the atmosphere, it cools off and condenses into clouds. Now, the growing, swirling vortex of air and clouds grows and grows and can become a thunderstorm.
So, the first condition needed for hurricanes is warmer waters in the Atlantic Ocean, which cause a number of other conditions favorable to hurricanes. It means a more unstable atmosphere, which is conducive to hurricanes intensifying," said Phil Klotzbach, an atmospheric scientist at Colorado State University. Another key factor: wind shear, or the change in wind direction with height into the atmosphere, Klotzbach said. Storms that form on different sides of the equator have different spin orientations, thanks to Earth's slight tilt on its axis, according to NASA.
The individual ingredients for hurricanes, however, don't pop up at random; they are guided by larger weather systems. The second climate pattern is the Atlantic Multidecadal Oscillation AMO , which is, as the name implies, a trend that lasts anywhere from 25 to 40 years and is associated with warmer waters in the Atlantic and stronger African monsoons, Bell said.
A warm-phase AMO conducive to hurricanes prevailed between and and since , Bell said. Officially, the Atlantic hurricane season starts on June 1 and runs until Nov. However, most of these storms hit during peak hurricane season between August and October, on both coasts, according to the National Weather Service's Climate Prediction Center. Following in the footsteps of the record-breaking hurricane season of , this year is expected to pack a punch, with above-average activity forecast by the National Oceanic and Atmospheric Administration NOAA.
To make their predictions, scientists analyze a host of factors, from wind speed to sea-surface temperatures. The Climate Prediction Center classifies hurricane seasons as above-normal between 12 and 28 tropical storms and between seven and 15 hurricanes ; near-normal Between 10 and 15 tropical storms and between four and nine hurricanes and below-normal Between four and nine tropical storms and two to four hurricanes.
On average, the world is seeing stronger tropical cyclones a term that encompasses fast-rotating storms such as hurricanes and typhoons more often than in decades past. According to an analysis of 4, tropical cyclones from to , researchers concluded in that due to global warming these storms are not only getting stronger , but we are experiencing the strongest of the pack more frequently, Live Science reported. KKKAT While reading the first paragraph of How Hurricanes Are Formed, the writer s should have used ITS which is possessive, not it's for It is when speaking about hurricanes.
Lastly, I lived in S. Florida for 9 years and experienced 5 hurricanes from Hurricanes Charley, Francis, Ivan and Jean. Just when I thought it was over, Hurricane Wilma struck late October Having had enough of hurricanes and the damage they leave behind, I moved to another location far north of where I lived before.
Been through 6 of them here in Port Saint Lucie.. They were horrifying to say the least. Some were short and some were relentless. All you can think of when is it going to pass. The stress is unbearable. The fear is strong. Going to sleep is impossible. Home owner in Florida, did notice during a active hurricane season hornets and wasps would nests on east side of house, is this a common occurrence that you know of?
Was really amazing when Charlie came through in 04 there were hundreders! Predictions seem to ignore the dust coming off of Africa. Dust seems to kill more storms than anything else, with the possible exception of wind shear. How dusty is Africa this year? Many factors go into these predictions, and we get them from the sources cited. Not every factor may be given. This Almanac is forecasting a major huricane in mid-September along the Florida—North Carolina coast and several tropical storms.
To your point, there have been at least a few heavy dust events this year off of Africa. In late January, satellies observed Saharan dust blowing all the way to Houston, Texas. Over February 22 and 23, a dust storm over the Canary Islands an event locally referred to as La Calima was carried on winds up of 75 mph and reduced visibility and disrupted air and land travel through Feb A week prior a massive cloud of dust darkened thousands of miles of West African coastline.
Another dust storm blew out from the coast of Morocco into the Atlantic on March 8. These events indicate that extremely dry air is coming off of the Sahara Desert. How dusty? WI nd direction and water temps are two big reasons that hurricanes tend not to occur along the US West Coast. Also, hurricanes north of the equator tend to move west-northwest.
So a storm that forms off the coast of Africa gets blown toward the Carribean and southern States, while a storm on a west-northwest path in the Pacific would steer away from the West Coast. That was a storm! We had no water or power for 3 weeks we had year old oak trees laying on the ground around our house But luckily not on the house. Finally the electric company got out to us and returned the power. That was Dora, funny thing is I was born in mount dora. It was the most nerve raking hurricane I have ever lived thru and, coming from NJ, I have lived thru many.
I have never seen such damage and have never seen the wind blow to it just became white before my eyes. I saw as the trains were blown right off the tracks, but in the end I saw how people came together to help each other in the time of need.
We really were strong. I lived for many years in NC and spent 17 years in Wilmington. I probably experienced 7 hurricanes during that time period. One year we had 3! We had plenty of time to prepare.
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