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Hurricanes: Science and Society
Glossary - C
C
Canadian Hurricane Centre
The Canadian Hurricane Centre (CHC) provides Canadians with meteorological information on hurricanes, tropical storms, and post-tropical storms to help them make informed decisions to protect their safety and secure their property. Source: CHC.
Cape Verde-type hurricane
An Atlantic basin tropical cyclone that develops into a tropical storm fairly close to (<1000 km [600 mi] or so) the Cape Verde Islands and then becomes a hurricane before reaching the Caribbean. Typically, they may occur in August and September, but in rare years (like 1995), there may be some in late July and/or early October. The quantities range from none up to around five per year - with an average of around two. Source: NOAA-HRD.
Caribbean Sea
A sea of the Atlantic Ocean situated in the tropics. It is bordered by the coasts of (clockwise from the south) the South American countries of Venezuela and Colombia on the south; the Central American countries of Panama on the southwest, and Costa Rica, Nicaragua, Honduras, Guatemala, Belize, and Mexico on the west; the Greater Antilles (Cuba, Jamaica, Hispaniola, and Puerto Rico) on the north, and the Lesser Antilles on the east. The entire area of the Caribbean Sea, the numerous islands of the West Indies, and adjacent coasts, are collectively known as the Caribbean.
center of a tropical cyclone
Generally speaking, the vertical axis of a tropical cyclone, usually defined by the location of minimum wind or minimum pressure. The cyclone center position can vary with altitude. In advisory products, refers to the center position at the surface. Source NOAA-NHC.
central north Pacific basin
The region north of the Equator between 140W and the International Dateline. The Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii is responsible for tracking tropical cyclones in this region. Source NOAA-NHC.
central pressure
At any given instant, the atmospheric pressure at the center of a tropical storm (or the center of any high pressure or low pressure system).
centrifugal force
The apparent force in a rotating system, deflecting masses radially outward from the axis of rotation.
climate
The prevalent long term weather conditions in a particular area. Climatic elements include precipitation, temperature, humidity, sunshine, wind velocity, and phenomena such as fog, frost, and hail storms. Climate cannot be considered a satisfactory indicator of actual conditions since it is based upon a vast number of elements taken as an average. Source: NOAA-NWS ERH.
climate change
Refers to all forms of climatic inconsistency. but is often used in a more restricted sense to imply a significant change. Within the media, climate change has been used synonymously with global warming. Scientists, however, use the term in a wider sense to include past climate changes also. Source: NOAA-NWS ERH.
climatology
The long-term average of one or more weather elements or ocean properties, such as temperature.
closed system
A thermodynamic system in which no heat or mass is transported across its boundaries. Source: (c) 1999, American Meteorological Society. Used with permission.
cloud
A visible cluster of tiny water droplets and/or ice crystals in the atmosphere. Source: NOAA-NWS ERH.
cloud droplets
Small particles of liquid water, approximately 4-100 micrometers in diameter, formed by the condensation of atmospheric water vapor. These small particles remain suspended in the air.
cold core low
At a given level in the atmosphere, any low that is generally characterized by colder air near its center than around its periphery; the opposite of a warm core low. The cyclonic intensity of a cold core low increases with height.
concentric eyewalls
An intense tropical cyclone will often have two eyewalls nearly concentric about the center of the storm, with the outer eyewall surrounding the inner one. A local wind maximum is generally present in each eyewall. Sometimes, more than two eyewalls occur. Source: (c) 1999, American Meteorological Society. Used with permission.
condensation
The process by which water vapor becomes a liquid; the opposite of evaporation, which is the conversion of liquid to vapor. Source: NOAA-NWS ERH.
continental shelf
The zone bordering a continent and extending to a depth, usually around 100 fathoms (183 m, 600 ft), from which there is a steep descent toward greater depth. Source: NOAA-NWS SRH.
convection
The vertical transport of heat and moisture, especially by updrafts and downdrafts in an unstable atmosphere. Source: NOAA-NWS ERH.
convergence
An atmospheric condition that exists when the winds cause a horizontal net inflow of air into a specified region. Divergence is the opposite, where winds cause a horizontal net outflow of air from a specified region. Source: NOAA-NWS ERH.
Coriolis force
Apparent effect of the earth’s rotation to deflect the direction of any object - including the wind - to the right in the northern hemisphere and to the left in the southern hemisphere. The Coriolis Force is responsible for giving a cyclone its spin, and without it, tropical cyclones would not form. Source: Canadian Hurricane Centre.
cryptic
Crypsis is the ability of an organism to avoid observation or detection by other organisms.
cumuliform cloud
A general term for a vertically-developed cloud (such as cumulus, cumulus congestus, and cumulonimbus). The most well-developed of the cumuliform clouds is the cumulonimbus, which is often capped by an anvil shaped cloud. Also called a thunderstorm cloud, cumulonimbus clouds are frequently accompanied by heavy showers, lightning, thunder, and sometimes hail, gusty winds, and/or tornadoes. Source: NOAA-NWS ERH.
cyclone
An atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Source NOAA-NHC.
cyclonic
Rotation that is counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. It is the opposite of anticyclonic. Source: Canadian Hurricane Centre.