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51 Cards in this Set
- Front
- Back
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a violent convective storm
characterized by thunder and lightning is a |
thunderstorm
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what type of cloud is a thunderstorm cloud
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cumulonimbus cloud.
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whn does A thunderstorm begins
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with the first
lightning bolt. |
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thunderstorms can occur anywhere thats unstable but what is needed
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warm
temperatures and abundant moisture |
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how many thunderstorms are happening at one time
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2000
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how many thunderstorms are happening per day
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48,000 per day.
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most common type of thunderstorm.
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Air Mass/Single Cell
Thunderstorms |
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Air Mass/Single Cell
Thunderstorms are most frequent where in the US |
in the SE -southeast (unstable mT air)
during the summer. |
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how long do Air Mass/Single Cell
Thunderstorms last |
about one hour
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charachteristics of Air Mass/Single Cell
Thunderstorms |
not severe, maybe some strong
winds and small hail. |
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Three development stages of Air Mass/Single Cell
Thunderstorms: |
cumulus,
mature, dissipating. |
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3 stages of cumulus stage
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updraft of condensation - precipitaton falls -
precipitation hits ground |
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updrafts and downdrafts occur in what stage
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mature stage
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3 charachteristics of mature stage
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cloud expands vertically upward to 40,000 ft. Gusty winds, heavy rains, lightning, small hail. downdrafts stop inflow of condensation
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in mature stage, what stops inflow of condensation
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downdrafts
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in mature stage, how high do cumulus clouds form
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40,000 ft high
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charachteristics of dissipating stage
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Downdrafts are dominant.
• Anvil (shape)is all that remains. • Gusty winds |
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stage of cloud - cloud is 10 km high - updraft
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cumulus stage
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stage of cloud - cloud is 13 or so km high - updraft AND downdraft
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mature stage
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stage of cloud - cloud is 15 km high - downdraft
-lightt rain |
dissipating
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what is Electrical discharge between (excessively)
positive and negative charged bodies (clouds, ground) |
lightning
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why does lightning occur
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attempt to equalize the difference
in charge. |
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how does lightning begin
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positively charged ions
move to the top of the cloud leaving negatively charged ions in lower sections. |
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two connecting parts of lightning
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electrons from cloud base AND
positively charged ions upward from earth objects. |
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stepped ladder
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starting at the base/bottom of the cloud, electrons are
released forming a conductive path |
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diameter/thickness of lightning
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The actual bolt is only a few centimeters
thick |
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lightning can heat air how much
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10,000 C, which is hotter than the surface
of the sun |
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what produces thunder
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rapid expansion of the air caused by
the heating . |
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severe storm charachteristics
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last longer than
others, producing heavy rain, large hail, strong winds and frequent lightning. |
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2 things that keep severe storm active
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• These storms have upper level wind
support which allows the updrafts to persist. • They move so that they can maintain the inflow. |
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Large, rotating, single-cell storm
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supercell
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supercell charachteristics
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Require very unstable air and strong
vertical wind shear • Winds increase in speed and change direction with height |
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supercell can last 12 plus hours because
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strong
vertical wind shear vertical - up and down |
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supercells found in – Western U.S.
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Low precipitation (LP) – not associated
with much rain but may produce large hail, few tornadoes |
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supercells found in –southeast U.S.
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High precipitation (HP) – produce
copious amounts of rain, hail, and rainwrapped tornadoes |
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supercells found in –tornado ally
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not too much or too little
moisture; produce hail and highly visible tornadoes |
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squall lines
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• Narrow band of thunderstorms in various
stages of development. • May be composed of supercells. • Often produce strong winds and heavy rains. Tornadoes may occur in certain places. • May last several hours. |
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Bow echo –
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caused by areas
of stronger winds aloft that push the squall line forward |
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Derecho
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A widespread and long-lived windstorm that
is associated with fast moving storms |
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where do Derecho
occur |
Associated with squall lines & bow echoes
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how are deracho formed
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Mid-level winds are brought to the surface
by downdrafts. |
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Winds in deracho may be how fast
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130 mph.
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(MCC’s)
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Mesoscale Convective Complexes
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mcc definition - what is it
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Cluster of thunderstorms which interact
and develop additional thunderstorms |
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how large are mcc's
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the size of iowa
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charachteristics of mcc (think of basic storm at home)
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• Develop in the late afternoon and persist
into the next morning. • May produce severe weather initially, but will transition to a significant rain producer. |
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states that benefit from mcc and why
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Critical to Midwest agriculture.
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A rapidly rotating column of air in contact
with the cloud and the ground. |
tornado
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tornado - how wide - how fast
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Can be over a mile wide with wind speeds
approaching 320 miles an hour |
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how many tornados occur per year
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Approximately 1000 occur in the United
States each year. |
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Most tornadoes occur with supercells. true or false
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TRUE
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