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