Severe Weather

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Severe Weather
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Thunderstorm

• localized weather condition
• high intensity short duration
• cumulonimbus clouds
• precipitation (usually rain)
• wind gusts
• thunder lightning

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Life Cycle of a Thunderstorm Cell

• Cumulus, mature, and dissipating stages
• updrafts vs. downdrafts
• entire process takes only 30 minutes to an hour
• multicellular storms most common

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Cumulonimbus Development

• Vertical air motion
• cold fronts/squall lines
• ex. Springtime in Oklahoma
• convection
• ex. Summer in most of the U.S.
• large mountains (orographic)
• ex. Colorado Rockies
• convergence
• ex. Florida sea breezes

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Distribution of Thunderstorms
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Thunderstorm Hazards

• Downburst
• Very strong downdraft
• potentially destructive
• Flash flood
• may result from torrential rains

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Lightning Thunder

• Electrical discharge
• cloud to cloud vs. cloud to ground
• air expands produces a sound wave
• travels 5 seconds/mile

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Hail

• with severe or supercell thunderstorms
• hailstones
• balls and lumps of ice
• milky vs. clear layers
• formation in different parts of the cloud

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Readingpp. 552-554Homework