thunderstorms
Download
Skip this Video
Download Presentation
Thunderstorms

Loading in 2 Seconds...

play fullscreen
1 / 19

Thunderstorms - PowerPoint PPT Presentation


  • 189 Views
  • Uploaded on

Thunderstorms. Thunderstorms. Definition: a storm containing lightning and thunder. Associated with midlatitude cyclones, localized convection, orographic lifting and tropical cyclones. Thunderstorm Formation. Ingredients warm, moist air (often mT)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Thunderstorms' - abena


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
thunderstorms2
Thunderstorms
  • Definition: a storm containing lightning and thunder.
  • Associated with midlatitude cyclones, localized convection, orographic lifting and tropical cyclones.
thunderstorm formation
Thunderstorm Formation
  • Ingredients
    • warm, moist air (often mT)
    • unstable (or conditionally unstable if lifting mech.)
    • encouraged by diverging air aloft
slide5
The Geography of Thunderstorms

Frequency decreases with distance from equator. None above 60o

Most occur during summer’s warm temperatures.

thunderstorm frequency
Thunderstorm Frequency
  • Probably 1500 to 2000 thunderstorms active around the world at any given time.
violent associations
Violent Associations
  • Hail
  • Downbursts(Microbursts)
  • Lightning and thunder
  • Tornadoes
slide10
Hail
  • Formation
  • Largest? Coffeyville, KS, 1970 (1.75 lb, 14 cm diameter)
downbursts
Downbursts
  • Macrobursts - extreme downdrafts associated with thunderstorms.
  • Microburst
    • smaller
    • < 5 minute duration
    • winds up to 146 mph
lightning
Lightning
  • discharge of electricity that occurs in mature thunderstorms
  • Cause: charge separation in cloud sets up electrical potential
  • Role of lightning is to equalize these differences in electrical potential.
  • Important fixer of Nitrogen.
slide13
Stepped leader Upward leader Return stroke

Electrons down Protons up Circuit complete

Repeats every few microseconds with new leader.

frequency of occurrence
Frequency of Occurrence

Globally, lightning flashes  100 times per second.

usa real time lightning
USA: Real-time Lightning

http://www.weather.com/

thunder
Thunder
  • Air poor conductor of electricity
  • Huge electrical potential develops
  • Lightning bolt ‘superheats’ the air (30,000C, 54,000 F)
  • Surrounding air expands violently  sound wave
distance from the thunderstorm
Distance from the Thunderstorm
  • Speed of light: 300,000,000 km/s
  • Speed of sound: about 343 m/s
  • Distance calculation
    • for each 3 seconds, 1 km away
    • for each 5 seconds, 1 mile away
key points
Key Points
  • Thunderstorm formation and life cycle
  • Thunderstorm geography and frequency
  • Violent associations
    • hail, downbursts, lightning/thunder
    • next lecture….tornadoes
ad