The Nature of Storms - PowerPoint PPT Presentation

the nature of storms n.
Skip this Video
Loading SlideShow in 5 Seconds..
The Nature of Storms PowerPoint Presentation
Download Presentation
The Nature of Storms

play fullscreen
1 / 65
The Nature of Storms
Download Presentation
Download Presentation

The Nature of Storms

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. The Nature of Storms pics

  2. Do now Q. • Why is it almost always windy at the shore?

  3. Local Winds • Wind directions change from day to night

  4. Global Winds H jhhj L H L

  5. Local Winds • Uneven Surface heat absorption/loss rates • Surface °T differences lead to air °T & P differences • High P Low P air air Wind Water Land Slow Heating/Cooling Fast Heating/Cooling

  6. cumulonimbus Sea Breeze High P Low P Warm cold Sea Breeze Water Land

  7. Land Breeze cumulonimbus High P Low P cold Warm Land Breeze Water Land

  8. Review Local Winds • Land and Sea Breeze • Sea Breeze • Land Breeze

  9. Valley & Mountain Breezes Cold Mountain Breeze Valley Breeze warm

  10. Land, Water, and Air °T changes • Worksheet Graph & Qs. • Lab: Land, Water T absorption rates

  11. Do Now Q. • What are some atmospheric signs that may indicate an approaching thunderstorm? • Video time lapse thunderstorm

  12. Stages of Thunderstorm • 1) Cumulus Stage • mT ~ Warm and Humid air • mT moves/rises/pushed up • Warm up drafts • Cumulus cloud forms Cumulus updraft updraft cP Warm Breeze cP mT

  13. Stages of Thunderstorm Cumulonimbus • 2) Mature stage • mT ~ Up drafts • Cumulonimbus • Precipitation • Rain ~ cooling of air • down draft • weaker up drafts • stronger down drafts Up draft Up draft Down draft Down draft Down draft Warmand cool Breeze Breeze

  14. Stages of Thunderstorm • 3) Dissipation Stage • Clouds fall apart/sky clears up • No more precipitation • no warm updrafts • Only down drafts Down draft Down draft Down draft Cool/cold Breeze Breeze

  15. Stages of Thunderstorm • Video time lapse thunderstorm • Everyday weather thunderstorm 1/5 • HW thunderstorm

  16. Thunderstorms • Map of Thunderstorms cP mT

  17. Thunderstorms

  18. Thunderstorms • Do now Q. • Why can thunderstorms become dangerous?

  19. Features of Thunderstorms • lightning

  20. Features of Thunderstorms • Lightning & Thunder • Light & Sound • Cumulonimbus up and down drafts • Friction between water/ice particles • Static electricity build up • Discharge of excess electricity • Heated gas particles ~ plasma “glow” • Particles move apart quickly • Collision of particles ~ sound Up draft Down draft

  21. Lightning Stepped leaders electrons Streamers +ions Return stroke

  22. Lightning Cloud to cloud in cloud Cloud to ground

  23. Lightning & Thunder 300,000 Km/s 0.33 Km/s • Light waves movefaster than Sound waves Sound Wave Sound Wave Light Wave Time Lapse Less distance/time More distance/time

  24. Lightning Safety • Lightning Safety

  25. Lightning Safety • Highest object • Outdoor sports/activity • Conductors: Water

  26. Lightning • Roy Cleveland Sullivan (1912-1983) was a park ranger in Shenandoah National Park in Virginia. Between 1942 and 1977, Sullivan was hit by lightning seven times, which earned him an immortal place in the Guinness Book of World Records. “The Human Lightning Rod ” Read more at

  27. Features of Thunderstorms • Tornadoes • Mature stage • Up and down drafts • Rotating air column • Vertical column • CCW rotation • * Land

  28. Stages of a Tornado Tornadoes

  29. Tornado

  30. Tornado Fujita Tornado Scale: F 0 - F 5 Wind speed ~ Max. 300 Km/hr Duration ~ min. – hr Path of Destruction ~ area • Tornadoes • Everyday weather part 3/5 Tornadoes cP Tornado Alley mT

  31. Tornado • Path Prediction • Watch • Thunderstorm • Warning • tornado in the area

  32. Hail in June

  33. Features of Thunderstorms Hail & sleet mT Cumulonimbus Mature stage weak/no up drafts • Sleet • Hail • Weaker up drafts

  34. Tornado • SGCM: 13.2 Tornadoes

  35. Features of Thunderstorms

  36. Lightning • Lightning has fascinated and excited humans for as long as they have watched the skies. Although meteorologists understand the cloud conditions necessary to produce it, lightning cannot be forecasted. At any moment, there are as many as 1,800 thunderstorms in progress somewhere on Earth, and each is producing deadly lightning. Lightning detection systems in the U.S. see an average of 25 million strokes of lightning each year, from some 100 thousand storms. It is estimated that the Earth is struck by 100 lightning bolts every second. • The clouds at the high levels of the thunderstorm are made of ice crystals. The formation of ice in a cloud is an important element in the development of lightning. Those storms that fail to produce large numbers of ice crystals may also fail to produce a lot of lightning. Strong rising and sinking motions within the cloud are important too, as they enhance collisions among cloud particles causing a separation of electrical charges. Positively charged ice crystals rise to the top of the thunderstorm and negatively charged ice particles and hailstones drop to the middle and lower parts of the storm. • As the differences in charges continue to increase, positive charges rise up taller objects such as trees, houses, and telephone poles. The charge can also move up you, causing your hair to stand on end! This is natures final way of warning you that lightning can strike near you very soon. • If the negatively charged area at the bottom of the storm gets large enough, sends out a channel toward the ground called a step leader. It is invisible to the human eye and moves in steps toward the ground. When the step leader nears the ground, or a target like a radio tower, it repels all the negatively charged in the surrounding area, and attracts all the positive charge. As the positive charges collect in high enough concentration, they send out small bolts of ground to air lightning called streamers. If the streamers can make contact with the step leader, an electric current wave propagates up the channel as a bright pulse -- lightning!

  37. Lightning • Dr. Megavolt • Lightning

  38. Lightning • Lightning

  39. Lightning Safety • safety

  40. Thunderstorms • Map of Thunderstorms cP mT

  41. NOAA Satellite • Identify and locate CCW and CW cloud rotations on the satellite imagery. • Cloud rotations • Reasons: • Winds • Pressure differences • Coriolis Effect CCW CW

  42. Pressure Centers H • Cyclone isolated Low pressure warm air mass Winds • CCW rotation • Toward the center L H H H

  43. Pressure Centers L • Anticyclone isolated High pressure cold air mass Winds • CW rotation • Away from the center H L L L

  44. Pressure Centers


  46. Review Pressure Centers • NOAA Satellite • Lab Weather Map • “Wind Circulation around High & Low Pressure Centers. • Cyclone & Anticyclone wind rotation & direction

  47. Cyclones • Identify and locate a cyclone on the satellite imagery. • Explain your reasons why it is a cyclone.