Violent Weather Chp 20 Types of Clouds: High: 6000m & above
(cirro) Middle: m (alto) Low: surface to 2000m (stratus) Which
produce rain, snow, hail, lightning? Air masses: The main reason
for violent weather in mid west
mA: cool, moist, unstable cA: cold, dry, stable mP: cool, moist,
unstable cP: cold, dry, stable mT: warm, moist, usually unstable
cT: hot dry, stable (high), unstable (surface) 1. Cold Front: Cold
air hits warm air
Types of Fronts: 1. Cold Front: Cold air hits warm air Cloud
formation precipitation 2. Warm Front: warm air hits cold air Cold
Front cirrostratus Warm Front cirrostratus 3. Occluded Front: 4.
Stationary front:
When an active cold front overtakes a warm front Cloud type formed
Precipitation 4. Stationary front: Surface position of front does
not move Precipitation (gentle to moderate if at all) Occluded
front formation Stationary Front Thunderstorm Formation 1
Thunderstorm Formation 1. Cumulus cloud develops into thunderhead
(cumulonimbus clouds) when warm humid rising air currents create an
unstable environment, due to frontal lifting (cold front; cold vs.
warm). 2. Mature thunderstorm: Ascending air reaches height where
precipitation occurs (Cloud top, Anvil). Initially, cloud air
warmer than surrounding air. Causing condensation and
precipitation. Falling rain & ice cool cloud air (energy
released). Downdrafts created. Up & downdrafts create friction
(electric unevenness) make lightening. 3. Final: Entire cloud
downdrafts. Surrounding air is adiabatic warmed. No airascending
& cooling. Precipitation decreases (excess energy gone).
Lightning Formation: Where there is lightning there is thunder.
Why
Lightning Formation: Where there is lightning there is thunder.
Why? Can lightning hit the same place twice? Up & down drafts
charge partials Lightning review: What areas have what charge?
Why?
What is the charge of the step leader, dart leader and return
stroke? What is the difference between the stepped leader and the
dart leader? What will cause the cloud to neutralize? Can lightning
hit the same place twice?
What causes thunder? Can lightning hit the same place twice? You
will not be tested on this. For your information only. Hail
formation: ice circulation in cumulonimbus cloud due to
updrafts
How does hail become golf ball sized? Overshooting top Tropopause
Anvil Mammatus Warm Front Cold Front Associated with supercells
(severe thunderstorms)
Tornado Formation Associated with supercells (severe thunderstorms)
1. Wind shear: sudden change in wind speed & direction 2.
Updrafts tilt rotation of funnel cloud to vertical (in developing
thunderhead) Tornado formation continued
3. Up drafts (mesocyclone) accelerate rotation removing air from
center (eye) creating low pressure. Funnel could touches the ground
-Air of funnel cloud & tornado can be see due to condensation
(like cloud) -What does the low pressure of the eye do? Tornado
formation pictures
2. Funnel Cloud 1. Wind Shear 3. Tornado Super cell Anatomy
Anatomy: tropopause, overshooting top, mammatus, anvil, up-drafts,
warm air, down-drafts, cool air, tornado, hail, heavy rain, light
rain, cold front, warm front Tornado Classification:
Frequency: 29% 40% 24% 6% 2%