Severe Weather Storms Objectives List and describe the
Severe Weather Storms
Objectives • List and describe the main types of storms and explain how they form • Standards: – S 6 E 4. b – Relate unequal heating of land water surfaces to form large global wind systems and weather events such as tornadoes and thunderstorms. – S 6 E 4. c – Relate how moisture evaporating from the oceans affects weather patterns and the weather events such as hurricanes.
Weather vs. Climate : condition of the atmosphere at a certain time and place : average weather conditions of an area over a long period of time. • described in terms of temperature and precipitation
STORMS • A storm is a violent disturbance in the atmosphere. • They involve sudden changes in air pressure. • Changes in air pressure causes rapid air movement (wind).
Thunderstorms Formation Temperature Precipitation Safety • Within large cumulonimbus, or thunderheads • Form when warm air is forced upward at a cold front • Hot, humid • Heavy rainfall afternoons in the • Sometimes hail spring and summer • Avoid touching metal objects • Install metal lightening rods • Find a low area away from trees • Stay away from water
Thunderstorms - a usually brief, heavy storm that consists of rain, strong winds, lightning, and thunder • occur along • Two atmospheric conditions are required for thunderstorm: warm moist air near Earth’s surface and an unstable atmosphere – Unstable atmosphere = surrounding air colder than the rising air mass.
Thunderstorms • During a thunderstorm, positive and negative electrical charges build up in the clouds. • The discharge of the electricity between clouds is lightning. • Lightning is as hot as 30, 000°C, hotter than the sun. • The heated air expands and explodes producing thunder.
Tornado • Rapidly whirling, funneled-shaped cloud that reaches down from a storm cloud to touch Earth’s surface • Usually brief, touching the ground approx. 15 minutes or less • Wind speeds may reach 480 km/hr
Tornado Formation Temperature Precipitation Safety • Develop in low, heavy cumulonimbus clouds • When warm dry air mass and cool air mass collide • Warm humid • Heavy rain and air wind • Spring and early summer when ground is warm • Listen for watches & warnings • Basement level, or to the middle room on ground floor • Stay away from windows • Lie in a ditch
Tornado • Tornado Watch – tornadoes are possibly in your area • Tornado Warning – tornadoes have been seen in the sky or on weather radar • Occur most often in the US • Approx. 800 tornadoes a year
- Slides: 10