Tropical Storm Dean was a strong tropical storm that affected at least twelve islands along its path from the tropical

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

to east of

Atlantic Canada Atlantic Canada, also called the Atlantic provinces (french: provinces de l'Atlantique), is the region of Eastern Canada comprising the provinces located on the Atlantic coast, excluding Quebec. The four provinces are New Brunswick, Newfoundlan ...

in August 2001. Dean developed from a

tropical wave A tropical wave (also called easterly wave, tropical easterly wave, and African easterly wave), in and around the Atlantic Ocean, is a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which ...

on August 22 over the

Lesser Antilles The Lesser Antilles ( es, link=no, Antillas Menores; french: link=no, Petites Antilles; pap, Antias Menor; nl, Kleine Antillen) are a group of islands in the Caribbean Sea. Most of them are part of a long, partially volcanic island arc betwe ...

, and was initially predicted to intensify further to reach hurricane status. However, strong

wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...

quickly weakened Dean to cause it to dissipate on August 23. The remnants turned northward, and redeveloped on August 26 to the north of

Bermuda ) , anthem = "God Save the King" , song_type = National song , song = " Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , e ...

. Located over warm waters and in an area of favorable conditions, Dean steadily strengthened while moving to the northeast, and peaked just below hurricane status on August 27 about 465 miles (750 km) southwest of

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

. The storm subsequently weakened over cooler waters, and became

extratropical Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...

on August 28. The precursor tropical wave dropped heavy rainfall and produced moderate winds throughout the

, though no serious damage was reported. In

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

, rainfall of up to 12.7 inches (322 mm) produced widespread flooding across the island. Thousands were left without power or water, and two houses lost their roofs from the storm. The passage of Dean resulted in $7.7 million (2001 USD, $9.4 million 2008 USD) in damage in Puerto Rico. The storm produced light to moderate rainfall in

and later in

, though no damage was reported.

Meteorological history

A large tropical wave with minimal convection moved off the coast of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

near

Dakar Dakar ( ; ; wo, Ndakaaru) (from daqaar ''tamarind''), is the capital and largest city of Senegal. The city of Dakar proper has a population of 1,030,594, whereas the population of the Dakar metropolitan area is estimated at 3.94 million in 2 ...

between August 14 and August 15. It moved westward, and gradually developed thunderstorms across the wave axis. On August 21, while located about 450 miles (725 km) east of the

, convection increased further within the system, though unfavorable upper-level

prevented rapid development. It continued to become better organized, and though a Reconnaissance flight into the system reported strong winds, it lacked a surface circulation. Late on August 21 the wave passed through the northern Lesser Antilles, and subsequent to a decrease in wind shear the system became much better organized on August 22. A surface circulation formed, and the system developed into Tropical Storm Dean on August 22 near

Saint Croix Saint Croix; nl, Sint-Kruis; french: link=no, Sainte-Croix; Danish and no, Sankt Croix, Taino: ''Ay Ay'' ( ) is an island in the Caribbean Sea, and a county and constituent district of the United States Virgin Islands (USVI), an unincorpo ...

. Dean was upgraded directly to a tropical storm due to the presence of 50 mph (80 km/h) winds in the storm. Reconnaissance Aircraft and surface reports confirmed the existence of a circulation. Dean moved northwestward at 22 mph (35 km/h), under the influence of the

Bermuda High The Azores High also known as North Atlantic (Subtropical) High/Anticyclone or the Bermuda-Azores High, is a large subtropical semi-permanent centre of high atmospheric pressure typically found south of the Azores in the Atlantic Ocean, at the Hor ...

to its northeast. The storm strengthened slightly to reach winds of 60 mph (95 km/h) later on August 22, though the circulation was exposed on the western edge of the convection due to the storm's quick forward motion and persistent

. Initial forecasts predicted the shear to decrease, allowing Dean to attain hurricane status with winds of over 80 mph (130 km/h). However, an upper-level

trough Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

produced an increase of shear over the storm, and by August 23 Dean weakened to a tropical depression. Hours later, the circulation dissipated, and Dean degenerated into a tropical wave to the east of the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...

. Regeneration was considered unlikely at the time. The remnants of Dean turned to the north, and became embedded within a large mid-level trough off the

East Coast of the United States The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the coastline along which the Eastern United States meets the North Atlantic Ocean. The eastern seaboard contains the coa ...

. Convection increased around the system early on August 24. The system became better organized, with indications of a broad surface circulation forming about 400 miles (645 km) west-southwest of

. However, a reconnaissance flight into the remnants of Dean reported a broad

low pressure area In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...

with the strongest winds and convection located far from the area of minimum pressure, indicating it had some non- tropical characteristics. The weak disturbance passed to the west of Bermuda early on August 25, and subsequently began to drift to the northeast. The remnants of Dean produced convection near its developing circulation, and on August 26, while located 220 miles (350 km) north of Bermuda the system organized sufficiently enough to be re-classified a tropical depression. Operationally, the

National Hurricane Center The National Hurricane Center (NHC) is the division of the United States' NOAA/National Weather Service responsible for tracking and predicting tropical weather systems between the Prime Meridian and the 140th meridian west poleward to the 3 ...

did not re-initiate advisories until fifteen hours later. The depression continued to the northeast, and re-strengthened into Tropical Storm Dean early on August 27 while located 580 miles (930 km) south of

Halifax, Nova Scotia Halifax is the capital and largest municipality of the Canadian province of Nova Scotia, and the largest municipality in Atlantic Canada. As of the 2021 Census, the municipal population was 439,819, with 348,634 people in its urban area. The ...

. The convection became better organized, and Dean steadily strengthened as it tracked northeastward. A ship near the center of Dean confirmed the storm re-developed. The convection near the center greatly organized, and an eye feature began to develop. Remaining over warm waters, Dean continued to strengthen and reached peak winds of 70 mph (110 km/h) late on August 27 while located about 465 miles (750 km) southwest of

Cape Race Cape Race is a point of land located at the southeastern tip of the Avalon Peninsula on the island of Newfoundland, in Newfoundland and Labrador, Canada. Its name is thought to come from the original Portuguese name for this cape, "Raso", mea ...

. The eye feature failed to develop further, and after maintaining its peak intensity for 12 hours Dean weakened over progressively cooler waters. The convection quickly diminished, and on August 28 Dean became

while located 145 miles (235 km) east-southeast of Cape Race, Newfoundland. The extratropical storm continued northeastward until being absorbed by a frontal low on August 29.

Impact and preparations

Caribbean

About a day before Dean developed, the National Hurricane Center advised interests in the northern and central

to monitor the progress of the storm. Routine statements issued by the National Hurricane Center warned for the possibility of strong winds and heavy rains. However, because Dean formed after it passed the islands, no tropical cyclone warnings or watches were issued. The precursor disturbance dropped heavy rainfall on Saint Martin of around 5 inches (129 mm). The precursor disturbance to Tropical Storm Dean produced 1.07 inches (27 mm) of rain in Saint Thomas, where winds reached 40 mph (64 km/h) with gusts to 48 mph (77 km/h). On

, the system produced 0.49 inches (12 mm) of rain and peak wind gusts of 47 mph (76 km/h). There, minor flooding was reported. Moderate wind gusts downed small trees and branches in Saint Croix and Saint John, and some roads were damaged in Saint John, as well. Heavy rains and gusty winds caused power outages throughout the U.S. Virgin Islands. The passage of Tropical Storm Dean resulted in minor damage totaling to $20,000 (2001 USD, $24,400 2008 USD). Tropical Storm Dean dropped heavy rainfall across

, peaking at 12.7 inches (322 mm) in Salinas. Winds were generally light across the island. The passage of Dean resulted in widespread flooding in eastern and southern Puerto Rico, collapsing two bridges and one road. Several highways were under water, and one car was swept away by the floodwaters. The four inside the vehicle were later rescued and unharmed. Throughout the island, about 1,320 houses were flooded, and two houses experienced collapsed roofs. The rains left various towns without power or water. By the night after the storm passed the island, more than 16,000 were without power, while almost 70,000 lacked potable water. Over 130 people were evacuated from low-lying areas to hurricane shelters. Two people were injured in Peñuelas, and three were injured in Nagüabo when the ceiling of a day care center collapsed, though no deaths occurred on the island. One airline canceled seventeen flights in and out of the island, and one cruise line was required to alter its path to both Dean and earlier due to

Tropical Storm Chantal The name Chantal has been used for eight tropical cyclones worldwide: seven in the Atlantic Ocean and one in the South-West Indian Ocean. In the Atlantic: *Hurricane Chantal (1983), formed near Bermuda and dissipated in the open ocean. *Hurricane C ...

. Damage in Puerto Rico totaled to $7.7 million (2001 USD, $9.4 million 2008 USD), of which $2.1 million (2001 USD, $2.6 million 2008 USD) was from agricultural damage.

Bahamas, Bermuda, and Canada

Shortly after Dean formed, the government of the

issued a

tropical storm warning Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local popul ...

for the southeastern Bahamas and the

Turks and Caicos Islands The Turks and Caicos Islands (abbreviated TCI; and ) are a British Overseas Territory consisting of the larger Caicos Islands and smaller Turks Islands, two groups of tropical islands in the Lucayan Archipelago of the Atlantic Ocean and n ...

. When the storm weakened and ultimately dissipated, the warnings were canceled. The remnants of Dean produced unsettled conditions across

, including a wind gust of 41 mph (66 km/h) and light rainfall of 0.31 inches (8 mm). The passage of Dean resulted in the coldest day of August 2001 on the island. Dean produced wind gusts peaking at 63 mph (103 km/h) in

, along with rainfall up to 4.2 inches (107 mm) in eastern Newfoundland. On land, wave heights reached 30 feet (9.3 m), while a

buoy A buoy () is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. Types Navigational buoys * Race course marker buoys are used for buoy racing, the most prevalent form of yac ...

offshore reported a peak wave height of 47 feet (14.4 m).

References

External links

NHC Tropical Cyclone Report for Tropical Storm Dean
{{DEFAULTSORT:Dean (2001) 2001 Atlantic hurricane season Atlantic tropical storms Hurricanes in Puerto Rico Hurricanes in Bermuda Hurricanes in Canada