Tropical Cyclones

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A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. They form over warm tropical or subtropical waters and derive their energy from the evaporation of water from the ocean surface, which then condenses to form clouds and rain when it reaches cooler air. Tropical cyclones are classified based on their intensity, with tropical depression being the weakest form and hurricane (in the Atlantic and Northeast Pacific), typhoon (in the Northwest Pacific), or cyclone (in the South Pacific and Indian Ocean) being the strongest form.

A tropical cyclone is one of nature's most powerful and destructive forces. In the United States, it is the most costly type of natural hazard type Between 1980 and 2002, tropical cyclones caused $1,333.6 billion in damage, with an average cost of $22.2 billion per event -- the highest average event cost among all natural hazard types[1].

This article talks about the change in tropical cyclone with climate change. https://www.climate.gov/news-features/blogs/beyond-data/2023-historic-year-us-billion-dollar-weather-and-climate-disasters

Impacts

The major hazards associated with hurricanes are[2]:

  • storm surge and storm tide
  • heavy rainfall and inland flooding
  • high winds
  • rip currents
  • tornadoes

The primary hazards from tropical cyclones (which include tropical depressions, tropical storms, and hurricanes) are storm surge flooding, inland flooding from heavy rains, destructive winds, tornadoes, and high surf and rip currents[3].

  • Storm surge is the abnormal rise in water level caused by a storm's winds, which can exceed 20 feet in height and extend across hundreds of miles of coastline. When combined with the astronomical tide, this rise in water level is known as storm tide. Storm surge can push several miles inland, particularly along bays, rivers, and estuaries. The immense power of storm surge, coupled with large, battering waves, can lead to loss of life, destruction of buildings, erosion of beaches and dunes, and damage to roads and bridges along the coast. Historically, storm surge has been the leading cause of hurricane-related deaths in the United States.
  • Flooding from heavy rainfall is the second leading cause of fatalities from landfalling tropical cyclones. Tropical cyclones often bring widespread, torrential rains exceeding 6 inches, which can lead to deadly and destructive floods. Such flooding can continue for several days even after the storm has dissipated. The amount of rainfall is not directly tied to the strength of a tropical cyclone but is influenced by the storm's speed, size, and the geography of the affected area. Slower-moving and larger storms tend to produce more rainfall, and mountainous terrain can further intensify rainfall from a tropical cyclone.
  • Winds from a hurricane can destroy buildings and manufactured homes. Debris, such as signs, roofing material, and other items left outside can become flying missiles during hurricanes. Winds can stay above hurricane strength well inland. In 2004, Hurricane Charley made landfall at Punta Gorda on the southwest Florida coast and produced major damage well inland across central Florida with gusts of more than 100 mph.
  • Tornadoes can accompany landfalling tropical cyclones. These tornadoes typically occur in rain bands well away from the center of the storm; however, they can also occur near the eyewall. Usually, tornadoes produced by tropical cyclones are relatively weak and short-lived, but they still pose a significant threat.
  • The powerful waves produced by a tropical cyclone's strong winds can pose a significant hazard to coastal residents and mariners. When these waves break along the coast, they can produce deadly rip currents which can pull even the strongest swimmers away from shore. These waves can also cause significant beach erosion and damage to coastal structures, even at a large distance (e.g. more than 1000 miles) from the storm.

Dataset Information

National Hurricane Center Historical Database

Context: The National Hurricane Center (NHC) performs detailed post-storm analysis of each tropical cyclone in the Atlantic basin, which includes the North Atlantic Ocean, Gulf of Mexico, and Caribbean Sea, as well as the North Pacific Ocean. This comprehensive examination utilizes all available observations to officially assess the cyclone's history, including data not available in real-time. The NHC is also committed to regularly updating the historical record as new analyses are reviewed.

Visualization

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a geographical map showing the tracks of selected cyclones from both the Atlantic and Pacific basins. Blue lines represent Atlantic cyclones, while green lines represent Pacific cyclones. This map provides a visual representation of the paths taken by these cyclones.


Content: The NHC releases the tropical cyclone historical data in a database known as HURDAT (HURricane DATabase). This repository consists of the Atlantic HURDAT2 and the NE/NC Pacific HURDAT2 databases. They provide six-hourly updates on various aspects of all known tropical and subtropical cyclones, including their location, maximum winds, and central pressure. Since 2004, the database also includes the size of these cyclones.

  • Data Type: Gridded, historical database
  • Coverage: Atlantic basin, North Pacific Ocean
  • Temporal Resolution: Six-hourly intervals
  • Variables:
    • Location (Latitude, Longitude)
    • Maximum Winds (knots)
    • Central Pressure (millibars)
    • Size parameters (nautical miles, post-2004)
  • File Format: CSV, PDF
  • Update Frequency: Post-storm analysis, with regular updates

Sample Entry

Below is an example of how data is recorded in the HURDAT database[4]:

ID Name Date Time Event Status Latitude Longitude Maximum Wind
AL011851 UNNAMED 18510625 0 HU 28.0N 94.8W 80
AL011851 UNNAMED 18510625 600 HU 28.0N 95.4W 80


Usage

Researchers, meteorologists, and the public can utilize the HURDAT databases for various purposes, such as climatological studies, risk assessment, and educational projects.



Accessing the Data

  • Database for Policy Decision Making for future climate change https://www.coast.dpri.kyoto-u.ac.jp/d4PDF/index_en.html A large ensemble of climate simulations at 60-km resolution and dynamically downscaled to 20 km. It is designed for climate change risk assessments in various research areas such as natural hazard, hydrology, civil engineering, agriculture, health, and insurance.[5] Download

The HURDAT databases can be accessed through the following links:

Ocean data

Damage and Loss

Others

Citation