chapter 6 the restless sky Flashcards
what is the largest and most locally intense storm on the planet
EF5 tornado
storm systems derive energy from
- solar heat from the earth
- condensation of water vapor in the atmosphere
microscale atmospheric systems last ___. synoptic atmospheric systems last ___.
hours
weeks
thunderstorm
a cumulonimbus cloud that produces lightning and thunder
thunderstorms are embedded within larger synoptic scale systems such as
- tropical cyclones
- midlatitude cyclones
- the ITCZ
air mass
a large region of air, extended over thousands of km, that is uniform in temperature and humidity
three types of thunderstorms
single cell thunderstorms
multicell thunderstorms
supercell thunderstorms
two important factors in determining thunderstorm type
atmospheric humidity and wind shear
wind shear
changes in wind speed and direction with altitude
single cell thunderstorms
mild and short lived, form within mT air masses where wind shear is weak, develop late afternoon, typically predictable
multicell thunderstorms
forms under moderate conditions of wind shear, form along fronts rather than within, arranged in clusters
squall line
a line of multicell thunderstorm cells that typically forms along a cold front on a mid latitude cyclone
severe thunderstorm conditions
produce either hail 2.54 cm in diameter, a tornado, or wind gusts of 93 km/h or greater
supercell thunderstorm
a severe thunderstorm containing a rotating cylindrical updraft
mesocyclone
the rotating portion of a supercell thunderstorm
produces almost all powerful tornadoes
lightning (kachoww)
the electrical discharge produced by thunderstorms
thunder
acoustic shock wave produced when lightning rapidly heats and expands the air around it
fulgurite
a glassy hollow formed as lightning melts sand (wowYY)
tornado
a violently rotating column of air that descends from a cumulonimbus cloud and touches ground
wall cloud
a cylindrical cloud that protrudes from the base of a mesocyclone from which a tornado may descend
funnel cloud
is the same as a tornado, but does not make contact with the ground
enhanced fujita scale
a system used to rank the strength of a tornado
tornado watch
alert issued by National Weather Service when conditions are favourable for tornadic thunderstorms
tornado warning
warning issued by NWS after tornado has been seen and called in to local authorities or is suggested by Doppler radar hook echo signature
tropical cyclone
a cyclonic low pressure system occuring in the tropics with sustained winds of 119 km/hr or greater
hurricane strength depends on how much ____ _____ condenses into liquid.
water vapour
tropical storm
tropical cyclonic storm with sustained winds between 63 and 118 km/hr
