Landfall

Last updated
Hurricane Maria losing its characteristic structure after making landfall in Puerto Rico Maria FT 20170920 0715 UTC.gif
Hurricane Maria losing its characteristic structure after making landfall in Puerto Rico

Landfall is the event of a storm or waterspout moving over land after being over water.

Contents

Tropical cyclone

A tropical cyclone is classified as making landfall when the center of the storm moves across the coast; in strong tropical cyclones this is when the eye moves over land. [1] This is where most of the damage occurs within a mature tropical cyclone, such as a typhoon or hurricane, as most of the damaging aspects of these systems are concentrated near the eyewall. Such effects include the peaking of the storm surge, the core of strong winds coming ashore, and heavy flooding rains. These coupled with high surf can cause major beach erosion. In low-lying areas, the storm surge can stay inland for a long time and mix with chemicals already in the area to create a toxic mess.[ citation needed ] When a tropical cyclone makes landfall, the eye closes in upon itself due to the weakening process, which causes surf to decrease. Maximum sustained winds will naturally decrease as the cyclone moves inland due to frictional differences between water and land with the free atmosphere. [2]

Tropical cyclone Is a rotating storm system

A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".

Eye (cyclone) region of mostly calm weather at the center of strong tropical cyclones

The eye is a region of mostly calm weather at the center of strong tropical cyclones. The eye of a storm is a roughly circular area, typically 30–65 km (20–40 miles) in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weather and highest winds occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm.

A storm surge, storm flood, tidal surge or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low pressure weather systems, the severity of which is affected by the shallowness and orientation of the water body relative to storm path, as well as the timing of tides. Most casualties during tropical cyclones occur as the result of storm surges. It is a measure of the rise of water beyond what would be expected by the normal movement related to tides.

Landfall is distinct from a direct hit. A direct hit is where the core of high winds (or eyewall) comes onshore but the center of the storm may stay offshore. The effects of this are quite similar to a landfall, as this term is used when the radius of maximum wind within a tropical cyclone moves ashore. [3] These effects are high surf, heavy rains that may cause flooding, water buildup along the coast with minor storm surge, coastal beach erosion, high winds, and possibly severe thunderstorms with tornadoes around the periphery.

Tornado or waterspout

When a tornadic waterspout makes landfall it is reclassified as a tornado, [4] which can subsequently cause damage to areas inland of the coast. When a fair weather waterspout makes landfall it usually dissipates quickly due to friction and a reduction in the amount of warm air supplied to the funnel. [5]

Waterspout weather phenomenon, intense columnar vortex that occurs over a body of water, commonly a non-supercell tornado over water

A waterspout is an intense columnar vortex that occurs over a body of water. Some are connected to a cumulus congestus cloud, some to a cumuliform cloud and some to a cumulonimbus cloud. In the common form, it is a non-supercell tornado over water.

See also

Related Research Articles

Cyclone large scale air mass that rotates around a strong center of low pressure

In meteorology, a cyclone is a large scale air mass that rotates around a strong center of low atmospheric pressure. Cyclones are characterized by inward spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars and Neptune. Cyclogenesis is the process of cyclone formation and intensification. Extratropical cyclones begin as waves in large regions of enhanced mid-latitude temperature contrasts called baroclinic zones. These zones contract and form weather fronts as the cyclonic circulation closes and intensifies. Later in their life cycle, extratropical cyclones occlude as cold air masses undercut the warmer air and become cold core systems. A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the subtropical jet stream.

The Saffir–Simpson hurricane wind scale (SSHWS), formerly the Saffir–Simpson hurricane scale (SSHS), classifies hurricanes – Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms – into five categories distinguished by the intensities of their sustained winds.

Hurricane Isidore Category 3 Atlantic hurricane in 2002

Hurricane Isidore was the ninth named storm and the second hurricane in the 2002 Atlantic hurricane season. Isidore was the fifth of eight named storms to occur in September. The tropical cyclone peaked as a Category 3 hurricane, causing damage as well as four fatalities in Jamaica, Cuba, Mexico, and the United States. Isidore is noted for threatening to strike the northern Gulf Coast as a Category 4 hurricane, but instead striking as a moderate tropical storm due to a track change that brought the storm over the Yucatán Peninsula for over a day, which significantly weakened the cyclone. Its primary impact was the heavy rainfall which fell across southeast Mexico and from the central United States Gulf coast into the Ohio Valley.

Hurricane Ophelia (2005) Category 1 Atlantic hurricane in 2005

Hurricane Ophelia was the fifteenth named tropical cyclone and the eighth hurricane of the 2005 Atlantic hurricane season. It was a long-lived storm that was most remembered for its very erratic and extremely slow track off the East Coast of the United States, alternating several times between tropical storm and hurricane intensity.

Hurricane Erin (1995) Category 2 Atlantic hurricane in 1995

Hurricane Erin was the fifth named tropical cyclone and the second hurricane of the unusually active 1995 Atlantic hurricane season. Erin began as a tropical wave off the west coast of Africa on July 22, but the storm crossed most of the Atlantic ocean without developing. On July 31, it developed a closed circulation and became a tropical storm. It made landfall on the central eastern Florida coastline as a Category 1 hurricane on August 2 and again along the Florida Panhandle as a Category 2 hurricane on August 3, causing a moderate amount of damage. The system reached its peak strength of 100 mph (155 km/h) and 973 millibars in central pressure just prior to the second landfall.

Tropical Storm Arlene (2005) Atlantic tropical storm in 2005

Tropical Storm Arlene was an unusually large and early-forming tropical storm, being the first of twenty-eight different storms during the 2005 Atlantic hurricane season, which would become the most active season on record. Tropical Storm Arlene formed near Honduras on June 8 and moved northwards. It crossed western Cuba on June 10 and strengthened to just under hurricane strength before making its final landfall on the Florida Panhandle the next day. The storm weakened as it continued to move north over the United States, becoming extratropical on June 13. Arlene was responsible for only one death and minor damages.

Tropical Storm Charley (1998) Atlantic tropical storm in 1998

Tropical Storm Charley was the third named storm of the 1998 Atlantic hurricane season. Charley was the first of two tropical storms to make landfall in Texas during that season. The storm originated with a tropical wave that moved off the West African coast on August 9. The wave moved generally west-northwestward, producing occasional bursts of convection, finally arriving in the southeastern Gulf of Mexico by August 19, when animated satellite images began to indicate it had possibly developed a low pressure center. Hurricane Hunter investigations into the system the next day revealed that this was not the case. The system lingered for two days, lacking an organized low level center of circulation until early on the morning of August 21, when advisories were initiated on the tropical depression, 185 miles (298 km) east of Brownsville, Texas. The depression became a tropical storm later that day, as it moved steadily west-northwestward, strengthening, and then weakening again before making landfall the next morning around Port Aransas, Texas. The storm moved slowly inland and finally dissipated on the morning of the August 24 near the town of Del Rio, Texas.

Tropical Storm Alberto (2006) first tropical storm of the 2006 Atlantic hurricane season

Tropical Storm Alberto was the first tropical storm of the 2006 Atlantic hurricane season. Forming on June 10 in the northwestern Caribbean, the storm moved generally to the north, reaching a maximum intensity of 70 mph (110 km/h) before weakening and moving ashore in the Big Bend area of Florida on June 13. Alberto then moved through eastern Georgia, North Carolina, and Virginia as a tropical depression before becoming extratropical on June 14.

Effects of tropical cyclones effect of cyclone

The main effects of tropical cyclones include heavy rain, strong wind, large storm surges near landfall, and tornadoes. The destruction from a tropical cyclone, such as a hurricane or tropical storm, depends mainly on its intensity, its size, and its location. Tropical cyclones act to remove forest canopy as well as change the landscape near coastal areas, by moving and reshaping sand dunes and causing extensive erosion along the coast. Even well inland, heavy rainfall can lead to mudslides and landslides in mountainous areas. Their effects can be sensed over time by studying the concentration of the Oxygen-18 isotope within caves within the vicinity of cyclones' paths.

Severe weather

Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms.

Hurricane Babe Category 1 Atlantic hurricane in 1977

Hurricane Babe was the second named storm and the first to impact the United States during the below-average 1977 Atlantic hurricane season. Forming out of a tropical wave on September 3, Babe began as a subtropical cyclone in the eastern Gulf of Mexico. The storm gradually intensified as it tracked westward. On September 5, the storm turned north and acquired enough tropical characteristics. Later that day, Babe intensified into a hurricane and attained its peak strength with winds of 75 mph (120 km/h) and a barometric pressure of 995 mbar. Several hours later, the hurricane made landfall in Louisiana and quickly weakened. By September 6, Babe had weakened to a tropical depression and later dissipated early on September 9 over North Carolina.

Mesovortices are small scale rotational features found in convective storms, such as those found in bow echos, supercell thunderstorms, and the eyewall of tropical cyclones. They range in size from tens of miles in diameter to a mile or less, and can be immensely intense.

Tropical Storm Beryl (2012) Atlantic tropical storm in 2012

Tropical Storm Beryl was the strongest off-season Atlantic tropical cyclone on record to make landfall in the United States. The second tropical cyclone of the 2012 Atlantic hurricane season, Beryl developed on May 26 from a low-pressure system offshore North Carolina. Initially subtropical, the storm slowly acquired tropical characteristics as it tracked across warmer sea surface temperatures and within an environment of decreasing vertical wind shear. Late on May 27, Beryl transitioned into a tropical cyclone less than 120 miles (190 km) from North Florida. Early the following day, the storm moved ashore near Jacksonville Beach, Florida, with peak winds of 65 mph (100 km/h). It quickly weakened to a tropical depression, dropping heavy rainfall while moving slowly across the southeastern United States. A cold front turned Beryl to the northeast, and the storm became extratropical on May 30.

1932 Florida–Alabama hurricane Category 1 Atlantic hurricane in 1932

The 1932 Florida–Alabama hurricane was a tropical cyclone that made two separate landfalls on the United States, causing devastation in affected areas. The third named storm and hurricane of the 1932 Atlantic hurricane season, it developed from a tropical disturbance north of Hispaniola on August 26. Slowly moving towards the west-northwest, the system intensified to tropical storm strength before making landfall on South Florida early on August 30. After crossing the Florida peninsula and entering the Gulf of Mexico, the system reached peak intensity as a Category 1 hurricane, before subsequently making its final landfall near the Mississippi–Alabama border on September 1. Over land, the hurricane weakened, and after becoming an extratropical cyclone on September 2, merged with another extratropical system over Quebec on September 4.

Hurricane Franklin

Hurricane Franklin was the first hurricane to make landfall in the Mexican state of Veracruz since Hurricane Karl in 2010. The sixth named storm, first hurricane and the first of ten consecutive hurricanes of the 2017 Atlantic hurricane season, Franklin formed on August 7 out of a tropical wave that was first tracked in the southeastern Caribbean Sea on August 3. The storm strengthened within a favorable environment and made landfall on the Yucatán Peninsula as a moderate tropical storm early on August 8 north of Belize. Weakening occurred as it crossed the peninsula, but Franklin re-emerged into the Bay of Campeche later that day, restrengthening quickly to become the season's first hurricane. It made landfall near Lechuguillas, Veracruz, on August 10 as a Category 1 hurricane, before rapidly weakening over the mountainous terrain of Mexico and dissipating shortly afterwards. On August 12, the storm's remnant mid-level circulation combined with a developing low in the Eastern Pacific to form Tropical Storm Jova.

References

  1. National Hurricane Center (2009). Glossary of NHC Terms: Landfall. Retrieved on 2009-02-05.
  2. Sim Aberson and Chris Landsea (2008). Subject : C2) Doesn't the friction over land kill tropical cyclones? Archived 2009-05-06 at the Wayback Machine . Retrieved on 2009-02-05.
  3. National Hurricane Center (2009). Glossary of NHC Terms: Direct Hit. Retrieved on 2009-02-05.
  4. Glossary of Meteorology (2009). Waterspout. Retrieved on 2009-02-05.
  5. Bruce B. Smith (2009). Waterspouts. Retrieved on 2009-02-05.