Hurricane Alley is an area of warm water in the Atlantic Ocean stretching from the west coast of northern Africa to the east coast of Central America and Gulf Coast of the Southern United States. Many hurricanes form within this area. The sea surface temperature of the Atlantic in Hurricane Alley has grown slightly warmer over the past decades. [1] A particularly warm summer in 2005 led climate scientists to begin studying whether this trend would lead to an increase in hurricane activity. [2]
Hurricanes form over tropical waters in areas of high humidity, light winds, and warm sea surface temperatures. These areas are usually between the latitudes of 8° and 20° north. [3] The perfect temperature for a hurricane is approximately 26 °C. This temperature has been set as a standard. If the water is colder the hurricane will most likely weaken, but if the waters are warmer rapid growth can occur. [4]
The area between 10° and 20°N create the most hurricanes in a given season because of the warmer temperatures. Hurricanes do not form outside this range because the Coriolis effect is not strong enough to create the tight circulation needed and above this range the temperatures are too cool. [5] The waters are only at the necessary temperatures from July until mid-October. In the Atlantic this is the height of the season.
Since hurricanes rely on sea surface temperature, sometimes an initially active season becomes quiet later. This is because the hurricanes are so strong that they churn the waters and bring colder waters up from the deep. This creates an area of the sea the size of the hurricane, which has cooler waters, which can be 5–10 °C lower than before the hurricane. When a new hurricane moves over the cooler waters they have no fuel to continue to thrive, so they weaken or even die out. [6]
According to an Azores High hypothesis of geographer Kam-biu Liu, an anti-phase pattern is expected to exist between the Gulf of Mexico coast and the North American Atlantic coast. During the quiescent periods (3000–1400 BC, and 1000 AD to present), a more northeasterly position of the Azores High would result in more hurricanes being steered towards the Atlantic coast. During the hyperactive period (1400 BC to 1000 AD), more hurricanes were steered towards the Gulf coast as the Azores High was shifted to a more southwesterly position near the Caribbean. [7] [8] Such a displacement of the Azores High is consistent with paleoclimatic evidence that shows an abrupt onset of a drier climate in Haiti around 3200 years BP, [9] and a change towards more humid conditions in the Great Plains during the late-Holocene as more moisture was pumped up the Mississippi Valley through the Gulf coast. Preliminary data from the northern Atlantic coast seem to support the Azores High hypothesis. A 3,000-year proxy record from a coastal lake in Cape Cod suggests that hurricane activity has increased significantly during the past 500–1,000 years, just as the Gulf coast was amid a quiescent period of the last millennium.[ citation needed ]
The Caribbean Sea is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles starting with Cuba, to the east by the Lesser Antilles, and to the south by the northern coast of South America. The Gulf of Mexico lies to the northwest.
The North Atlantic Oscillation (NAO) is a weather phenomenon over the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level (SLP) between the Icelandic Low and the Azores High. Through fluctuations in the strength of the Icelandic Low and the Azores High, it controls the strength and direction of westerly winds and location of storm tracks across the North Atlantic.
The 2006 Atlantic hurricane season was the least active since 1997 as well as the first season since 2001 in which no hurricanes made landfall in the United States, and was the first since 1994 in which no tropical cyclones formed during October. Following the intense activity of 2003, 2004, and 2005, forecasters predicted that the 2006 season would be only slightly less active. Instead activity was slowed by a rapidly forming moderate El Niño event, the presence of the Saharan Air Layer over the tropical Atlantic, and the steady presence of a robust secondary high-pressure area to the Azores High centered on Bermuda. There were no tropical cyclones after October 2.
The 1925 Atlantic hurricane season was a below-average Atlantic hurricane season during which four tropical cyclones formed. Only one of them was a hurricane. The first storm developed on August 18, and the last dissipated on December 1. The season began at a late date, more than two months after the season began. The official start of the season is generally considered to be June 1 with the end being October 31; however, the final storm of the season formed nearly a month after the official end. Due to increased activity over the following decades, the official end of the hurricane season was shifted to November 30.
A parent to the Florida Current, the Loop Current is a warm ocean current that flows northward between Cuba and the Yucatán Peninsula, moves north into the Gulf of Mexico, loops east and south before exiting to the east through the Florida Straits and joining the Gulf Stream. The Loop Current is an extension of the western boundary current of the North Atlantic subtropical gyre. Serving as the dominant circulation feature in the Eastern Gulf of Mexico, the Loop Currents transports between 23 and 27 sverdrups and reaches maximum flow speeds of from 1.5 to 1.8 meters/second.
This is a list of all known or suspected Atlantic hurricanes before 1600. Although most storms likely went unrecorded, and many records have been lost, recollections of hurricane occurrences survive from some sufficiently populated coastal areas, and rarely, ships at sea that survived the tempests.
In the Indian Ocean north of the equator, tropical cyclones can form throughout the year on either side of India, although most frequently between April and June, and between October and December.
An Atlantic hurricane or tropical storm is a tropical cyclone that forms in the Atlantic Ocean, primarily between the months of June and November. A hurricane differs from a cyclone or typhoon only on the basis of location. A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, and a cyclone occurs in the South Pacific Ocean or Indian Ocean.
Tropical cyclone observation has been carried out over the past couple of centuries in various ways. The passage of typhoons, hurricanes, as well as other tropical cyclones have been detected by word of mouth from sailors recently coming to port or by radio transmissions from ships at sea, from sediment deposits in near shore estuaries, to the wiping out of cities near the coastline. Since World War II, advances in technology have included using planes to survey the ocean basins, satellites to monitor the world's oceans from outer space using a variety of methods, radars to monitor their progress near the coastline, and recently the introduction of unmanned aerial vehicles to penetrate storms. Recent studies have concentrated on studying hurricane impacts lying within rocks or near shore lake sediments, which are branches of a new field known as paleotempestology. This article details the various methods employed in the creation of the hurricane database, as well as reconstructions necessary for reanalysis of past storms used in projects such as the Atlantic hurricane reanalysis.
Tropical Storm Beryl made landfall just south of the Mexico–United States border in mid-August 2000, causing minimal damage. The second named storm of the 2000 Atlantic hurricane season, Beryl originated from a tropical wave near the African coastline. Tracking westward, the wave failed to organize substantially until entering the Bay of Campeche, at which time it developed into a tropical storm. Beryl rapidly deepened while in the Gulf of Mexico, and it initially was forecast to strengthen to a hurricane under favorable conditions for development. Instead, Beryl remained at moderate tropical storm intensity and failed to intensify any further. It made landfall in the Mexican state of Tamaulipas as a weak tropical storm with winds of 50 mph (80 km/h) on August 15, 2000 and dissipated over mountainous terrain shortly thereafter. One death was reported in Mexico due to drowning. Otherwise, no significant damage was reported associated with Beryl, as it affected a sparsely populated area of Mexico.
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes.
Texas' weather varies widely, from arid in the west to humid in the east. The huge expanse of Texas encompasses several regions with distinctly different climates: Northern Plains, Trans-Pecos Region, Texas Hill Country, Piney Woods, and South Texas. Generally speaking, the part of Texas that lies to the east of Interstate 35 is subtropical, while the portion that lies to the west of Interstate 35 is arid desert.
The 2013 Atlantic hurricane season was a well below average Atlantic hurricane season and the first since 1994 with no major hurricanes. It was well below average for both hurricanes and major hurricanes but it was a slightly above average year for named storms. It was also the first season in the satellite era with no storms of at least Category 2 intensity on the Saffir–Simpson hurricane wind scale. The first tropical cyclone of the season, Andrea, developed on June 5, while the final cyclone, an unnamed subtropical storm, dissipated on December 7. Throughout the year, only two storms—Humberto and Ingrid—reached hurricane intensity; this was the lowest seasonal total since 1982.
Hurricane Sandy was the sixth-costliest Atlantic hurricane on record. It lasted for over a week in late October-early November 2012. Classified as the eighteenth named storm, tenth hurricane, and second major hurricane of the annual hurricane season, Sandy originated from a tropical wave on October 22. Performing a small loop over the central Caribbean Sea, the system intensified into a tropical storm a day later and became the final hurricane of the season before briefly coming ashore the coast of Jamaica on October 24. After emerging between Jamaica and Cuba, Sandy began a period of rapid intensification into a Category 3 hurricane on the Saffir–Simpson hurricane wind scale, with maximum sustained winds of 115 mph (185 km/h). It made landfall at this intensity near Santiago de Cuba on October 25.
The 2020 Atlantic hurricane season featured a total of 31 tropical or subtropical cyclones, making it the most active Atlantic hurricane season on record. All but one cyclone became a named storm. Of the 30 named storms, 14 developed into hurricanes, and a record-tying seven further intensified into major hurricanes. It was the second and final season to use the Greek letter storm naming system, the first being 2005, the previous record. Of the 30 named storms, 11 of them made landfall in the contiguous United States, breaking the record of nine set in 1916. During the season, 27 tropical storms established a new record for earliest formation date by storm number. This season also featured a record 10 tropical cyclones that underwent rapid intensification, tying it with 1995, as well as holding the record for most Category 4 hurricanes in a singular season in the Atlantic Basin. This unprecedented activity was fueled by a La Niña that developed in the summer months of 2020 as it did, continue a stretch of above-average seasonal activity that began in 2016. Despite the record-high activity, this was the first season since 2015 in which no Category 5 hurricane formed.
Nova Scotia lies in the mid-temperate zone, and although the province is almost surrounded by water, the climate is closer to continental climate rather than maritime climate. The temperature extremes of the continental climate are moderated by the ocean.
Hurricane Alex was the first Atlantic hurricane to occur in January since Hurricane Alice of 1954–1955. Alex originated as a non-tropical low near the Bahamas on January 7, 2016. Initially traveling northeast, the system passed by Bermuda on January 8 before turning southeast and deepening. It briefly acquired hurricane-force winds by January 10, then weakened slightly before curving towards the east and later northeast. Acquiring more tropical weather characteristics over time, the system transitioned into a subtropical cyclone well south of the Azores on January 12, becoming the first North Atlantic tropical or subtropical cyclone in January since Tropical Storm Zeta of 2005–2006. Alex continued to develop tropical features while turning north-northeast, and transitioned into a fully tropical cyclone on January 14. The cyclone peaked in strength as a Category 1 hurricane on the Saffir–Simpson scale (SSHWS), with maximum sustained winds of 85 mph and a central pressure of 981 mbar. Alex weakened to a high-end tropical storm before making landfall on Terceira Island on January 15. By that time, the storm was losing its tropical characteristics; it fully transitioned back into a non-tropical cyclone several hours after moving away from the Azores. Alex ultimately merged with another cyclone over the Labrador Sea on January 17.
Hurricane Ophelia was regarded as the worst storm to affect Ireland in 50 years, and was also the easternmost Atlantic major hurricane on record. The tenth and final consecutive hurricane and the sixth major hurricane of the very active 2017 Atlantic hurricane season, Ophelia had non-tropical origins from a decaying cold front on 6 October. Located within a favorable environment, the storm steadily strengthened over the next two days, drifting north and then southeastwards before becoming a hurricane on 11 October. After becoming a Category 2 hurricane and fluctuating in intensity for a day, Ophelia intensified into a major hurricane on 14 October south of the Azores, brushing the archipelago with high winds and heavy rainfall. Shortly after achieving peak intensity, Ophelia began weakening as it accelerated over progressively colder waters to its northeast towards Ireland and Great Britain. Completing an extratropical transition early on 16 October, Ophelia became the second storm of the 2017–18 European windstorm season. Early on 17 October, the cyclone crossed the North Sea and struck western Norway, with wind gusts up to 70 kilometres per hour (43 mph) in Rogaland county, before weakening during the evening of 17 October. The system then moved across Scandinavia, before dissipating over Norway on the next day.
Paleotempestology is the study of past tropical cyclone activity by means of geological proxies as well as historical documentary records. The term was coined by American meteorologist Kerry Emanuel.
