Transcript Storms - McEachern High School

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A tsunami is a wave or series of waves generated at sea by
the abrupt movement of a mass of seawater. This is usually
caused by the sea floor moving suddenly.
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Tsunamis travel fast in the open ocean, reaching 700km
per hour or more. Wind-generated waves travel at only 30 to
100km per hour
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Tsunamis can occur in any ocean, sea or large lake. Most
occur in the Pacific Ocean, originating in the zone around
the Pacific known as the Ring of Fire where there are
frequent earthquakes and volcanic eruptions
https://video.nationalgeographic.com/video/ https://www.youtube.com/watch?v=j0YOXVlP
news/japan-tsunami-2011-vin
Uu4
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Thunderstorms develop in warm, moist air in advance of
eastward-moving cold fronts
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During the spring in the Central Plains, thunderstorms
frequently develop along a "dryline," which separates very
warm, moist air to the east from hot, dry air to the west.
Tornado-producing thunderstorms may form as the dryline
moves east during the afternoon hours
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Tornado Alley= Kansas and the Great Plains
https://www.discovery.com/tv-shows/stormchasers/videos/tornado-near-miss.htm
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Blizzards occur in very Low temperatures ( usually below 20˚F)
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35mph winds with zero visibility
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These conditions go on for 3 hours or more
Deadliest Blizzard
- The 1972 blizzard in Iran lasted from February 3rd to 9th and killed
approximately 4000 people. In southern Iran, there was as much as
28 feet of snow. There were no survivors from the towns of Kakkan,
Kumar or Sheklab.
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Closed, circular motion system rotating in same direction as
Earth
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Spiraling winds, rotate CCW (N. Hemi) and CW (S. Hemi)
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Occur in areas of low pressure
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Extratropical: occur in mid latitudes; occur everyday and are
the cyclones that drive most weather patterns that occur on
Earth; 37 cyclones within 6 hr period
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Subtropical: broad wind patterns; no weather fronts
connected to center; lower temps for formation; form from
extratropical cyclones
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Tropical Cyclones: associated with numerous
thunderstorms, strong winds, heavy rain; center warmer
than surroundings at any height in atmosphere (also
referred to as hurricanes).
https://www.history.com/topics/hurricanekatrina/videos/hurricanekatrina?m=528e394da93ae&s=undefined&f
=1&free=false
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What conditions are necessary for a hurricane to form?
o Tropical cyclones form and intensify under specific set of necessary
conditions:
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Warm ocean waters of at least 78°F (26°C)
At least 5° latitude from the equator
Low vertical wind shear
Moisture in the mid-troposphere
Unstable Conditions
Pre-existing disturbance
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Where do most hurricanes develop on Earth? Why do they
develop there?
o Most develop either in the Caribbean or the Atlantic.
Many of the worst start as seedlings coming off the
coast of Africa.
o They develop in these areas because the water is warm
which feeds a storm with energy in order to form.
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What time of year is considered hurricane season?
o Summer to Mid-Fall (June 1 to November 30)
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Birth
o All hurricanes begin as an area of low pressure in the
atmosphere. This low-pressure area is called a tropical
disturbance.
Childhood to Teenager
o Once the system obtains a clearly identifiable circulation
center, the system is upgraded to a tropical depression. If
winds continue to intensify to greater than 39 mph, the
system will be classified as a tropical storm.
Adult
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Once winds are sustained above 74mph, the system is
officially upgraded to a hurricane.
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Adult
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Once winds are sustained above 74mph, the
system is officially upgraded to a hurricane.
Old Age to Death
o Once a hurricane makes landfall it can no longer extract
heat from the ocean. Since the air masses over land are
drier, less moisture is carried into the storm, cloud
coverage lessens, and air is cooled and then sinks.
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What is the eye?
o The relatively calm center in a hurricane that is at least halfway
surrounded by clouds comprising the eyewall. The winds are light,
the skies are partly cloudy or even clear. The eye diameter ranges
typically from as small as 5 to 10 mi. When the eye is shrinking in
size, the hurricane is generally intensifying.
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Factors that cause damage
Strong winds
Storm surge
Flooding
Tornadoes
Rip tides