BOATING SKILLS AND SEAMANSHIP

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BOATING SKILLS AND SEAMANSHIP

• Lesson 12
• Weather Boating

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Lesson Objective

• What Causes Weather
• Wind, Waves, And Weather
• Recognizing Signs Of Change
• Weather And Clouds
• The Signs Of Bad Weather What To Avoid
• Where To Get Weather Info

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Weather Heat

• Sun Heats Earth Air
• Warm Air Rises
• Creates Low Pressure
• Cooler Upper Air Falls
• Creates High Pressure
• Air Flows From Highs Toward Lows
• Creates Wind
• Greater The Pressure Difference
• Stronger The Wind

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Heat Humidity

• Warm Air Can Hold More Moisture Than Cold Air
• Relative Humidity
• The Amount Of Moisture In Air, Compared To The
  Maximum Amount It Could Hold At That Temperature
• Cooling Air To Its Dew Point Creates 100
  Relative Humidity And Moisture Condenses Out

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Land Water

• Water Gains Heat Slower Than Land
• Water Loses Heat Slower Than Land
• Daytime
• Land Warmer Than Water
• Air Warms, Rises Over Land And Air Flows In From
  Sea Sea Breeze
• Nighttime
• Water Warmer Than Land
• Air Warms, Rises Over Water And Air Flows From
  Land to Sea Land Breeze

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Wind Patterns
North Pole
Equator
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Buys-Ballots Law
Present Surface Wind
Stand with back to surface wind Turn Right
45o Low Pressure is on left
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Coriolis Force

• Northern Hemisphere
• Earths Rotation Causes Any Air Motion To Bend To
  The Right
• Air Moving Down Out Of A High Pressure Area
• Bends To The Right Causing A Clockwise Motion
• Air Rushing Into A Low Pressure Area
• Rises, Bends To The Left

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Circulation of Air
Circulation Of Air
Down, Out Clockwise around High
Toward Up Counterclockwise around lows
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Wind Waves

• Swells
• Dying Waves A Long Way From Source
• Breakers
• Waves Nearing Shore
• Caused By
• Shallow Water Slowing Bottom Of Wave, Top Then
  Spills Over Breaks

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Wind Waves

• Wave Height Depends On
• Wind Strength
• Wind Duration
• Fetch (Long Short)

Buffalo
Lake Erie
Toledo
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Wave Height

• Seas 3 to 5 Feet Means
• 15 Of Waves Over 5
• 15 Of Waves Under 3
• 70 Of Waves 3 to 5

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Fronts

• Defined As Zone Between Two Different Air Masses
• Differences In
• Temperature
• Humidity
• Wind Direction Speed
• Air Pressure

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Cold Fronts

• Air Cooler Behind Than Ahead
• Fast Moving
• Can Create Violent Weather
• When Passes
• Pressure Rises Abruptly
• Temperature Falls
• Relative Humidity Decreases
• Wind Shifts Direction

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Cold Fronts
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Warm Fronts

• Air Warmer Behind Than Ahead
• Slow Moving
• Non-Violent Weather
• Nighttime Fog Frequent
• Can Have Long Periods Of Rain
• When Passes
• Little Pressure Change
• Little Temperature Change

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Warm Front
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Cloud Identification

• Cumulus
• Fluffy, White, Fair Weather Clouds
• May Grow To Cumulonimbus
• Stratus
• Layered
• Nimbo/Nimbus
• Rain Clouds

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Cloud Families

• High - Cirriform
• Cirrus, Cirrocumulus, Cirrostratus
• Mostly Ice No Precipitation
• Middle - Alto
• Altostratus, Altocumulus, Nimbostratus
• Mostly Water
• Low
• Stratus, Stratocumulus, Cumulus
• Mostly Water

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High Clouds

• Cirrus
• Mares Tails
• Cirrocumulus
• Mackerel Scales
• Cirrostratus
• Like A Sheet Or Veil

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Cirrus (Ci)
Mares tails
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Cirrocumulus (Cc)
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Middle Clouds

• Altostratus
• Mid-level, Layered
• Altocumulus
• Cumulus Clouds Gathered In Layers
• Cumulonimbus
• Rain Clouds
• May Develop Into Thunderheads (Towering Cumulus)

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Cumulus Family

• Cumulus
• Summer Afternoon Cotton Balls
• Generally No Precipitation Unless Building
• Towering Cumulus
• Building Cumulus
• Deep Layer Of Unstable Air
• Thundershowers Can Result
• Cumulonimbus
• Thunderhead/Thunderstorm Cloud

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Cumulus
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Towering Cumulus (Tcu)
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Cumulonimbus (Cb)
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Altocumulus (Ac)
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Low Clouds

• Stratus
• Low Layers Of Solid Cloud Cover
• Nimbostratus
• Rain Clouds
• Intermittent Or Steady Rain

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Stratocumulus (Sc)
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Stratus (St)
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Turbulence In Cumulonimbus Cloud
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Stages Of A Thunderstorm
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Thunderstorms In A Squall Line
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Lightning

• Cause
• Friction Of Raindrops Ice Particles In
  Thunderstorms Creates Electrical Charge
• Distant Lightning
• Heard As Static In AM Radios
• More Frequent The Static, The More Severe The
  Storm

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Tornado
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Funnel Clouds
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Waterspout
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Fog

• Radiation
• Clear Sky
• Little Or No Wind
• Small Temp Dew Point Spread
• Burns Off In Morning
• Advection
• Sea Fog
• Needs Light Winds Up To 15 MPH
• Warm Moist Air Moving Over A Colder Body
• Long Lasting

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Fog
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Weather Information

• Radio
• Television
• Newspapers
• Telephone
• NOAA Weather Radio Stations
• Pennants, Flags, Lights

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Tropical Weather

• Classifications
• Tropical Depression
• Wind Up To 34 Knots
• Tropical Storm
• Wind 35 - 64 Knots
• Hurricane
• Wind 65 Knots Or More
• Other Names For Hurricanes
• Typhoon
• Cyclone
• Willy-Willy

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Hurricane Tracks
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SUMMARY (1)

• Heat Weather
• Global Air Circulation
• Wind Boating
• Highs Lows
• Frontal Weather

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SUMMARY (2)

• Clouds Weather
• Thunderstorms
• Fog
• Tropical Weather
• Sources Of Weather Information