Rapid deepening

Rapid Deepening

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Rapid deepening

Rapid deepening, also known as rapid intensification, is a meteorological

Meteorology

Meteorology is the interdisciplinary scientific study of the Earth's atmosphere that focuses on weather processes and forecasting . Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the eighteenth century....
condition that occurs when the minimum sea-level atmospheric pressure

Atmospheric pressure

Atmospheric pressure is sometimes defined as the force per unit area exerted against a surface by the weight of air above that surface at any given point in the Earth's atmosphere....
of a tropical cyclone

Tropical cyclone

A tropical cyclone is a storm characterized by a large low pressure system center and numerous thunderstorms that produce strong winds and flooding rain....
decreases drastically in a short period of time. The National Weather Service

National Weather Service

The National Weather Service , once known as the Weather Bureau, is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration of the United States Federal government of the United States....
describes rapid deepening as a decrease of 42 millibars

Bar (unit)

The bar , decibar and the millibar are units of pressure. They are not SI units, nor are they cgs units, but they are accepted for use with the SI....
in less than 24 hour

Hour

The hour is a unit of time. It is not an SI unit but is Non-SI units accepted for use with SI....
s.

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Encyclopedia

Rapid deepening, also known as rapid intensification, is a meteorological

Meteorology

Atmospheric pressure

Tropical cyclone

National Weather Service

Bar (unit)

The bar , decibar and the millibar are units of pressure. They are not SI units, nor are they cgs units, but they are accepted for use with the SI....
in less than 24 hour

Hour

The hour is a unit of time. It is not an SI unit but is Non-SI units accepted for use with SI....
s. However, this phrase is liberally applied to most storms undergoing rapid intensification.

Necessary conditions

In order for rapid deepening to occur, several conditions must be in place. Water temperatures

Sea surface temperature

Sea surface temperature is the water temperature close to the surface.In practical terms, the exact meaning of surface varies according to the measurement method used....
must be extremely warm (near or above 30°C, 86°F), and water of this temperature must be sufficiently deep such that waves do not churn deeper cooler waters up to the surface. Wind shear

Wind shear

Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind wind speed and wind direction over a relatively short distance in the Earth's atmosphere....
must be low; when wind shear is high, the convection

Convection

Convection in the most general terms refers to the movement of molecules within fluids . Convection is one of the major modes of heat transfer and mass transfer....
and circulation in the cyclone will be disrupted. Usually, an anticyclone

Anticyclone

In meteorology, an anticyclone is a weather meteorological phenomenon in which there is a descending movement of the air and a high pressure area over the part of the planet's surface affected by it....
in the upper layers of the troposphere

Troposphere

The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and almost all of its water vapor and particulate....
above the storm must be present as well — for extremely low surface pressures to develop, air must be rising very rapidly in the eyewall

Eye (cyclone)

The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30?65 km in diameter....
of the storm, and an upper-level anticyclone helps channel this air away from the cyclone efficiently.

Explosive intensification

Explosive intensification is a more extreme case of rapid deepening that involves a tropical cyclone deepening at a rate of at least 2.5 mbar

Bar (unit)

The bar , decibar and the millibar are units of pressure. They are not SI units, nor are they cgs units, but they are accepted for use with the SI....
per hour for a minimum of 12 hours. Explosive intensification is rather rare, as conditions must be exceedingly favorable for cyclone intensification. Explosive intensification occurs regularly in the West Pacific basin, with the greatest frequency off the north coast of Australia

Australia

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
; however, it has occurred numerous times in the Atlantic basin, as with 2008's Hurricane Ike

Hurricane Ike

Hurricane Ike IPA] was the third most destructive hurricane to ever make landfall in the United States. It was the ninth named storm, fifth hurricane and third major hurricane of the 2008 Atlantic hurricane season....
with the hurricane undergoing a 24 millibar pressure drop in 3 hours. However, this is not a true explosive intensification because this deepening did not last for 12 hours.

Instances

In 2004, Hurricane Charley

Hurricane Charley

Hurricane Charley was the third named storm, the second hurricane, and the second major hurricane of the 2004 Atlantic hurricane season. Charley lasted from August 9 to August 15, and at its peak intensity it attained 150 miles per hour winds, making it a strong Category 4 hurricane on the Saffir-Simpson Hurricane Scale....
was approaching the west coast of Florida

Florida

Florida is a U.S. state located in the Southeastern United States of the United States, bordering Alabama to the northwest and Georgia to the northeast....
as a category two storm on the Saffir-Simpson scale

Saffir-Simpson Hurricane Scale

The Saffir-Simpson Hurricane Scale is a classification used for most Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms, and thereby become hurricanes....
of hurricane strength. When just off the coast, however, its sustained winds rapidly increased from 110 to 150 mph

MPH

mph is a three-letter acronym that refers to miles per hour, a measurement of speedMPH may also refer to:* Master of Public Health, a Master's degree in public health...
(along with a pressure drop from 965 to 941 mbar) in only three hours. Charley caused unprecedented destruction in the Punta Gorda

Punta Gorda, Florida

Punta Gorda is a city in Charlotte County, Florida, Florida, United States. According to the U.S. Census Bureau estimates of 2007, the city had a population of 16,762....
area, and inflicted major damage across the state of Florida.

In 2005, the minimum central pressure of Hurricane Wilma

Hurricane Wilma

Hurricane Wilma was the most intense tropical cyclone ever recorded in the Atlantic basin. Wilma was the twenty-second tropical cyclone , thirteenth tropical cyclone, sixth major hurricane, and fourth Saffir-Simpson Scale hurricane of the record-breaking 2005 Atlantic hurricane season ...
dropped from 981 to 882 mbar in 24 hours, including an incredible drop of 53 mbar in less than 6 hours. This is by far the fastest intensification of any Atlantic hurricane, and possibly the fastest intensification for any system in recorded history. Typhoon Forrest

1983 Pacific typhoon season

The 1983 Pacific typhoon season has no official bounds, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November....
in 1983 may have strengthened faster, deepening from 976 to 876 mbar in just under 24 hours, but pressure estimates for this storm were much less accurate. 2005 was also notable in that two other storms, Katrina

Hurricane Katrina

Hurricane Katrina of the 2005 Atlantic hurricane season was the costliest Atlantic hurricane, as well as one of the five deadliest, in the history of the United States....
and Rita

Hurricane Rita

Hurricane Rita was the fourth-most intense Atlantic hurricane ever recorded and the most intense tropical cyclone ever observed in the Gulf of Mexico....
, also underwent episodes of extremely rapid intensification.

In 2006

2006 Pacific typhoon season

The 2006 Pacific typhoon season had no official bounds; it ran year-round in 2006, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November....
, the minimum central pressure of Typhoon Chebi in the Western Pacific dropped 75 mbar in 24 hours, including a 60 mbar pressure drop in 6 hours, as it intensified from a tropical storm to a category four equivalent typhoon in one advisory.

In 2008, Hurricane Ike

Hurricane Ike

Hurricane Ike IPA] was the third most destructive hurricane to ever make landfall in the United States. It was the ninth named storm, fifth hurricane and third major hurricane of the 2008 Atlantic hurricane season....
in the Atlantic basin was upgraded from a tropical storm to a Category 4 hurricane in just twelve hours, only a few days after Hurricane Gustav

Hurricane Gustav

The name Gustav has been used for five tropical cyclones in the Atlantic Ocean:* 1984 Atlantic hurricane season#Tropical Storm Gustav, spent most of its existence as a tropical depression hovering over Bermuda, no major damage...
underwent a similar episode of rapid intensification.

Rapid deepening

Necessary conditions

Explosive intensification

Instances

See also