the nature of storms
DESCRIPTION
Chapter 13.1. The nature of storms. Thunderstorms. Abundant source of moisture and latent heat that maintains warmth and upward motion The air must lift and condense, releasing the latent heat The atmosphere must become unstable. Thunderstorm Frequency. Air-mass Thunderstorms. - PowerPoint PPT PresentationTRANSCRIPT
THE NATURE OF STORMS
Chapter 13.1
Thunderstorms Abundant source of
moisture and latent heat that maintains warmth and upward motion
The air must lift and condense, releasing the latent heat
The atmosphere must become unstable
Thunderstorm Frequency
Air-mass Thunderstorms Caused by unequal heating of the Earth’s
surface Most common in the afternoons
Frontal Thunderstorms Caused by converging warm and cold
air masses More frequent during an advancing cold
front
Stages of a Thunderstorm
SEVERE WEATHERChapter 13.2
Severe Thunderstorms Cold fronts Low pressure systems Supercells- powerful self-sustaining
storms characterized by intense updrafts
Lightning Atmospheric discharge
of electric current Heats surrounding air
to 30,000oC This superheated air
expands rapidly producing the sound we call thunder
Wind Downbursts- violent downdrafts Macrobursts- area of 5km or more;
winds of more than 200km/h Microbursts- smaller area; deadlier;
harder to predict; winds exceeding 250km/h
Hail Supercooled water freezes and collides due
to strong updrafts and downdrafts Largest hailstone on record- 7 inches wide.
That’s almost the size of a soccer ball!!
Floods Rising water due to precipitation Flash floods- runoff occurring over a
short amount of time
Tornadoes Violent, rotating column of air that
contacts the ground
Tornado Distribution
Tornado Safety
TROPICAL STORMSChapter 13.3
Tropical Cyclones Large, rotating, low-pressure storms
Formation of Hurricanes
Classifying Hurricanes
Hurricane Hazards Storm surges are caused by hurricane-
force winds driving water up and inland