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AVIA 101 - FM1 > Meteorology 2 > Flashcards

Meteorology 2 Flashcards

1
Q

Clouds

A
  • Most visible means of determining weather conditions
  • Form when saturation is reached, causing water vapour to condense into small droplets or crystals
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2
Q

High Clouds (“Cirro-“ )

A
  • Bases at and above 20,000’ ASL (up to around 45,000’)
  • Average is about 25,000’
  • Composed of ice crystals
  • Have little effect on flying
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3
Q

Middle Clouds (“Alto-“ )

A
  • Bases between 6,500’ and 20,000’ ASL
  • Composed of ice crystals and water droplets most of which are super-cooled
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4
Q

Low Clouds

A
  • Bases located between surface and 6,500 ASL
  • Composed of water droplets which may be super-cooled or ice crystals
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5
Q

Clouds of Vertical Development “Cumul-“

A

Bases usually below 6,500’ ASL, extending potentially to the tropopause

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6
Q

Cumulus Clouds

A
  • Form in rising air
  • Indicate unstable air
  • “-cumulus”
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7
Q

Stratus Clouds

A
  • Form in horizontal layers
  • Layer of moist air is cooled below its saturation point
  • “-stratus”
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8
Q

Nimbus Clouds

A
  • Precipitation is Falling
  • “-nimbus” or “nimbo-“
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9
Q

High Clouds Main Types

A
  • Cirrus (CI)
  • Cirrostratus (CS)
  • Cirrocumulus (CC)
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10
Q

Middle Clouds Main Types

A
  • Altostratus (AS)
  • Altocumulus (AC)
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11
Q

Middle Clouds Secondary Types

A

Altocumulus Castellanus (ACC)

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12
Q

Low Clouds Main Types

A
  • Stratus (ST)
  • Nimbostratus (NS)
  • Cumulus (CU)
  • Stratocumulus (SC)
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13
Q

Low Clouds Secondary Types

A
  • Stratus Fractus (SF)
  • Cumulus Fractus (CF)
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14
Q

Clouds of Vertical Development Main Types

A
  • Cumulus (CU)
  • Cumulonimbus (CB)
  • Towering Cumulus (TCU)
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15
Q

Cirrus (CI)

A
  • Very High, up to 45,000’
  • Thin, wispy, feathery appearance
  • Called cats’ whiskers or mares’ tails
  • No significant icing
  • May be turbulent in dense, banded cirrus
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16
Q

Cirrocumulus (CC)

A
  • Take the form of individual puffs
  • Often form in patchy groups with spaces between the individual members
  • Thin cloud layer
  • Cotton or flake-like
  • May contain highly super-cooled water droplets resulting in some turbulence and icing
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17
Q

Cirrostratus (CS)

A
  • Continuous appearance than other high altitude clouds
  • Typically so thin that the sun/moon can be seen through them
  • Indicates and approaching warm front or occlusion
  • Little if any icing, no turbulence, restricted visibility
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18
Q

Altocumulus (AC)

A
  • Series of patches of rounded cotton-ball clouds
  • Formed in unstable mid-level air masses
  • Usually do not indicate any weather development
  • Small amounts of icing, some turbulence
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19
Q

Altocumulus Castellanus (ACC)

A
  • Altocumulus with a turreted appearance
  • Indicates increased instability, turbulence, and possible showers
  • Might develop into cumulonimbus
  • Unstable air, rough turbulence with some icing
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20
Q

Altostratus (AS)

A
  • Thick grey cloud covering large areas of the sky
  • Indicates the approach of a warm front
  • Light rain or snow could fall from the clouds
  • Moderate amounts of icing, little to no turbulence, restricted sunlight
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21
Q

Lenticular

A
  • Lens-shaped clouds
  • Associated with strong winds blowing over mountainous areas
  • Mountains cause a pattern of up and down waves
  • Form in the wave capping a prominent mountain peak, or in the wave crests in the lee of the mountain
  • It is not uncommon to have several layers of lenticular clouds stacked on top of each other
  • very strong turbulence
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22
Q

Stratus (ST)

A
  • Fairly uniform light to dark grey appearance
  • Typically blankets large areas of the sky
  • Bases usually found near the ground to around 6,500 feet
  • A stratus cloud with its base extending to the ground is fog
  • Drizzle is likely
  • Little or no turbulence
  • Hazardous icing if temps are near or below freezing
  • Visibility can be greatly reduced when associated with fog or precipitation
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23
Q

Stratus Fractus (SF)

A
  • Small, thin, unorganized tatters of a stratus layer that typically condense in the moisture beneath nimbostratus or cumulonimbus clouds
  • Pilots often refer to these clouds as “scud”
  • Bases usually found near the ground to around 6,500’
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24
Q

Stratocumulus (SC)

A
  • Irregular masses of cumulus clouds merged together with little or no spacing between the clouds
  • May be in layers or patches
  • Bases of these clouds are usually found near the ground to around 6,500’
  • Common in high pressure areas
  • Some turbulence, possible icing at subfreezing temps, ceiling and visibility better than with low stratus clouds
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25
Q

Nimbostratus (NS)

A
  • Often called rain clouds
  • Uniform dark grey appearance
  • Bottoms are typically blurred and indistinct due to falling rain or snow
  • Precipitation is continuous
  • Low bases, but may have considerable vertical development bringing the tops into the middle level range
  • Associated with warm fronts
  • Very little turbulence, serious icing problems if temps are near or below freezing
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26
Q

Cumulus (CU)

A
  • Thick, rounded, lumpy, cotton balls
  • Bases are normally flat
  • Form during the day, disappear at night
  • Flight is usually bumpy near cumulus
  • Called Cumulus Fractus (CF) when the appear ragged
  • Shallow layer of unstable air will give some turbulence, but no significant icing
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27
Q

Cumulus Fractus (CF)

A

Small, thin, unorganized puffs
- Dissipating cumulus clouds often dissolve into cumulus fractus
- Sometimes referred to as scud by pilots, although more applied to stratus fractus
- Bases usually found from near the ground to around 6500’

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28
Q

Towering Cumulus (TCU)

A
  • Also called Cumulus Congestus
  • Unstable air causes strong vertical convection currents
  • Can cause cumulus cloud tops to grow and billow upward beyond the range of the low clouds into the middle cloud altitudes
  • Early stage of thunderstorm
  • Very strong turbulence with rain showers, some clear icing above freezing level
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29
Q

Cumulonimbus (CB)

A
  • Thunderstorm
  • Extend well above freezing level
  • Top forms shape of anvil
  • Violent vertical currents in and near the cloud
  • Hail is within the cloud and could fall beneath it or outside of it
  • Line of CB’s indicate a cold front
  • CB’s could be embedded in stratus layers
  • Should be avoided
  • Unstable air throughout, violent turbulence, strong possibility of icing
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30
Q

Cumulus Mammatus

A
  • Cellular pattern of pouches hanging underneath the base of a cloud
  • Often associated with the anvil cloud that extends from a cumulonimbus
  • When occurring in cumulonimbus, indicate a particularly strong storm
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31
Q

Calculating Cloud Base

A
  • For altitude, spread divided by 2.5 then multiplied by 1000
  • Can also take temp spread and multiply by 400
  • For temperature, take surface temp minus 2 degrees per 1000’
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32
Q

Fog

A
  • Ground Level Cloud
  • Large impact on aviation
  • Can sometimes see through fog from above
  • Visibility usually less than 5/8 SM
  • Slant Range Visibility, Prevailing visibility, Vertical visibility, Tower visibility
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33
Q

Fog Composition

A
  • Small water droplets
  • Ice crystals
  • Super-cooled water droplets
  • Combination thereof
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34
Q

Important factors leading to fog

A
  • High relative humidity
  • Condensation nuclei
  • Temp/Dewpoint spread reduced to zero
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35
Q

High Relative Humidity

A
  • Air near the surface must be at or near saturation
  • Spread of less than 4ºC
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36
Q

Condensation Nuclei

A
  • Water vapour requires a particle to condense on to
  • Dust, pollen, volcanic ash, sea salt, pollution
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37
Q

Temp/Dewpoint Change

A
  • Can happen two ways
  • Cooling air to the dew point
  • Adding moisture to raise the dew point
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38
Q

Radiation Fog

A
  • Best known type of fog
  • Typically forms at night
  • Requires clear skies, light winds, stable air
  • Caused by radiation cooling, air mass cools from the ground up
  • will burn off as sun rises and warming continues
  • Can dissipate gradually if there is a cloud layer
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39
Q

Advection Fog

A
  • Warm, moist air travels over cooler land or water surface
  • As long as warm air flows over the surface, advection fog will persist
  • Wind speeds up to 15 knots provide maximum thickness
  • Tends to occur in maritime areas
  • Can occur behind a warm front advancing on a very cold air mass
  • Can persist for days, until the wind direction changes or surface warms
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40
Q

Upslope Fog

A
  • Light winds push warm, moist air upslope
  • Cools adiabatically and condenses into fog
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41
Q

Steam Fog

A
  • Cold air passes over warm water
  • Evaporation occurs, increasing the dew point and cooling the air
  • Fog forms
  • Occurs over rivers and lakes
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42
Q

Frontal (Precipitation) Fog

A
  • Rain or drizzle adds moisture to the air through evaporation
  • Evaporation also cools the air
  • Happens with warm fronts
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43
Q

Ice Fog

A
  • Moist air on an extremely cold day
  • Addition of water vapour to air increases dew point
  • Sublimation of water vapour forms ice crystals
  • Vapour trails in the sky
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44
Q

Valley Fog

A
  • Version of radiation fog
  • Cold air drains down mountain side
  • Cools air in valley to dew point
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45
Q

Haze

A
  • Microscopic water droplets, dust, or salt particles suspended in the air
  • Pollution makes haze worse
  • Stable air only
  • Appears bluish, dirty yellow, or orange
  • Can severely limit flight visibility
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46
Q

Sky Condition and Visibility

A
  • Amount of cloud cover described as clear, few, scattered, broken, or overcast
  • Ceiling is first layer of Broken or Overcast
  • VFR operations require 3 SM visibility
  • Visibility can be reduced by clouds, precipitation, fog, haze, smoke, snow
  • Visibility tends to be less in stable air
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47
Q

Visual Meteorological Conditions (VMC)

A

Ceiling, distance from clouds, and visibility are equal or better than the minimum required for VFR flight

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48
Q

Instrument Meteorological Conditions (IMC)

A
  • Ceiling, distance from clouds, or visibility are less than the minimum required for VFR flight
  • Flights must be IFR
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49
Q

Precipitation

A
  • In clouds at above freezing temps
  • Water droplets combine and become heavy and fall to Earth
  • Vertical movement causes droplets to collide, called coalescence
  • Various forms of precipitation
  • In clouds with temps below freezing, ice crystals and water droplets exist at same level
  • Water droplets evaporate and water vapour sublimates
  • Air temp determines if it is snow or rain
  • Heavy precipitation indicates significant vertical development to above the freezing level
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50
Q

Drizzle

A
  • Very small droplets of water
  • Fairly uniform
  • Max diameter 0.5 mm
  • Falls very slowly, forms no rings on puddles
  • Limited vertical movement within the cloud
  • Usually from stratus clouds, also stratocumulus
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51
Q

Rain

A
  • Larger drops than drizzle
  • Diameter over 0.5 mm
  • Forms rings on puddles
  • Freezing rain is super-cooled water droplets that freeze on contact
  • Stratus, cumulus, cumulonimbus
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52
Q

Hail

A
  • Large vertical development clouds have layers
  • Lower layer is water, middle layer is water and ice, top layer is ice crystals
  • In middle layer, super cooled water droplets and ice crystals collide forming soft ice balls
  • When it falls through a water region it picks up water and freezes
  • Finally falls out of cloud as hail
  • Larger hail means greater vertical currents in the cloud
  • Cumulonimbus
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53
Q

Snow Pellets

A
  • White, opaque ice particles
  • Soft hail
  • If water region is not thick, hard shell will not freeze on the pellet
  • Cumulonimbus
54
Q

Snow

A
  • Water vapour sublimates directly to ice crystals which join to form snow flakes
  • Stratus, nimbus, and cumulus, cumulonimbus
55
Q

Air Masses

A
  • Large section of troposphere with uniform properties of temperature and moisture horizontally
  • Takes on properties of the surface where it forms
  • May be modified by the surface it moves across
  • Weather determined by moisture content, cooling process, stability
56
Q

North American Air Masses - Continental Arctic (cA)

A

Cold dry air mass from the far North (permafrost) in winter

57
Q

North American Air Masses - Continental Polar (cP)

A
  • Cool dry air mass from not as far north or a modified cA
58
Q

North American Air Masses - Maritime Arctic (mA)

A
  • Cold wet air mass
  • Formed over the Arctic in the summer
  • In winter cA moves South and picks up moisture over the North Atlantic or North Pacific
59
Q

North American Air Masses - Maritime Polar (mP)

A

Moves farther South over the ocean and is warmed as it picks up moisture

60
Q

North American Air Masses - Maritime Tropical (mT)

A

Formed in the warm, moist sections of North America (Caribbean, Pacific)

61
Q

North American Air Masses - Continental Tropical (cT)

A
  • Formed over warm, dry section of North America (Mexico)
  • Only in Summer
62
Q

Fronts

A
  • Air masses tend not to mix
  • Cold, dense air does not mix well with warmer, less dense air
  • Boundary between air masses is called a front
  • Air masses only mix slightly at borders
  • Temperature remains fairly uniform in each air mass
  • There will be a large temp change in an area about 50-100 miles wide between air masses (Frontal Zone)
63
Q

Cold Front

A
  • Cold air is advancing
  • Blue lines with triangles on maps
  • Cold air overtaking warm air at the surface
  • Friction from ground in teardrop shape
  • Cumulus clouds form from warm air being pushed up quickly (Thunderstorm may develop)
  • Fast moving front may have Squall Line if front is undercutting unstable air
64
Q

Warm Front

A
  • Cold air is retreating
  • Red lines with semi-circles on maps
  • Warm air is overtaking and replacing cold air
  • Warm lacks direct push since it slides up and over the cold air, causing cold air to retreat slowly
  • Produces a gradual frontal slope
  • Clouds can form up to 500 miles ahead of a warm front
65
Q

Stationary Front

A
  • Cold air is neither advancing or retreating
  • Alternating symbols on maps
  • Winds are parallel to the front, usually weaken and dissipate
  • Weather is similar to a warm front
66
Q

Polar Front

A
  • Dome of cold air covers polar regions
  • Warm air mass covers equatorial regions
  • Two air masses meet in the temperate regions but do not mix
  • Transition called polar front
  • Several air mass domes over the pole
  • Boundary between mP and mT is the Polar Front
67
Q

Frontal Waves

A
  • Form along any of the air mass fronts
  • On both sides of the front, wind is blowing parallel to the front but in opposite directions
  • A disturbance will cause a bend
  • Disturbances include cold air pushing against warm air, vice versa, pressure differences, terrain
  • Counter clockwise circulation develops
  • One part becomes a cold front and one a warm front, called a frontal wave
  • Circulation becomes stronger and the two fronts move, low pressure area forms
  • Cold front moves faster than the warm front, occlusion begins
  • The two fronts close together when the cold front catches up to the warm front
68
Q

Clouds and Weather at Moist Stable Warm Front

A
  • Cirrus, Cirrus Stratus, Alto Stratus, Nimbo Stratus, Stratus
  • Precipitation will fall ahead of front
  • May be heavy rain
69
Q

Clouds and Weather at Moist Unstable Warm Front

A
  • Cumulonimbus will be embedded in clouds
  • Heavy showers ahead of the surface front
70
Q

Weather at Warm Front

A
  • Changes are gradual but might cover a large area
  • Wind will veer (change direction to the right)
  • Gradual rise in temperature
  • Low ceilings and poor visibility at the front
  • Turbulence is minimal unless cumulonimbus embedded
  • Precipitation begins well ahead of the front and gets heavier as front approaches (very heavy means CB)
71
Q

Winter Warm Front

A
  • Different areas of the front have varying precipitation
  • Good to notice while flying: WHAT COULD BE AHEAD?
72
Q

Weather at the Cold Front

A
  • Wind veers and becomes gusty
  • Temp drops slowly over hours
  • Visibility improves after the cold front has passed
  • Pressure decreases as the front approaches, rises quickly after the passage
  • Turbulence present if convective activity
  • Precipitation is narrow band of showers
  • May bring freezing rain and icing
73
Q

Occluded Front

A
  • As cold front overtakes warm air mass, it eventually catches up with itself as it flows around the low pressure area
  • May be cold type or warm type
  • Weather similar to a warm front in either case
  • May be thunderstorms if warm air is unstable
74
Q

TROWAL

A
  • All warm air lifted up at an occluded front
  • TRough Of Warm air ALoft
  • Usually some form of precipitation
75
Q

Upper Cold Front

A
  • Advancing cold front meets other colder air and rises up over the colder air
  • Cold front is now an upper cold front
76
Q

Upper Warm Front

A

Warm air rises up over colder surface air

77
Q

Icing

A
  • When super cooled water hits an aircraft, it will freeze and stick to the airplane
  • Ice affects all parts of the aircraft
78
Q

Clear Ice

A
  • Large drops freeze slowly
  • Clear, glassy, hard
  • Forms on leading edge and spreads backwards over the wing surface
  • Forms in clouds and precipitation, with temps just below freezing
79
Q

Rime Ice

A
  • Small droplets freeze rapidly
  • Frost-like
  • Opaque, whitish, granular, brittle due to trapped air
  • Weighs less than clear, but disrupts flow more
  • Forms in cloud, stable air
  • Forms on leading edge, but does not spread back
80
Q

Mixed Icing

A
  • Combination of Clear and Rime
  • Snow and water droplets
  • Severe icing occurs in Cumulus cloud
  • Less sever icing in Stratus cloud
81
Q

Effects of Icing - Wings and Control Surfaces

A
  • Ice alters shape
  • Tail plane especially susceptible to ice
82
Q

Effects of Icing - Propellers

A
  • Reduction in thrust
  • May put blades out of balance
83
Q

Effects of Icing - Windscreens

A

Visibility reduced

84
Q

Effects of Icing - Pitot Tubes and Static Ports

85
Q

Effects of Icing - Radio Antennae

A
  • Reduces transmission efficiency
  • Could cause them to break off
86
Q

Effects of Icing - Carburetors and Air Intakes

A

Could reduce air flow to the point of engine stoppage

87
Q

De-Icing Equipment

A
  • De-icing boots expand to break ice
  • Heated wings, props, windshield
  • Fluid released through leading edge or onto prop
88
Q

Icing Intensity

A
  • If severe, de-icing equipment cannot keep up
  • If moderate, may have to alter altitude or divert
  • If light, normally not a problem for a short duration
  • Intensity depends on type of aircraft and type of de-icing equipment
89
Q

Icing Avoidance

A
  • De-icing equipment is meant to give you some time to escape, not for continued flight in icing
  • Even aircraft certified for “flight in known icing” are usually only tested in light icing conditions
  • Monitor OAT gauge
  • Avoid flying in cloud at temps near freezing
  • If icing encountered, turn around, descend to warmer air, climb, file a PIREP
90
Q

Frost

A
  • Aircraft parked outside on a clear, cold night
  • May be frost or frozen dew
  • Any frost or frozen dew MUST be removed before flight
  • Layer similar to coarse sandpaper can reduce lift by 30% and increase drag by 40%
91
Q

Thunderstorms

A
  • Extremely hazardous for flying
  • Thunder, lightning, strong vertical drafts, severe gusts and turbulence
  • Must be high moisture content, unstable (steep) lapse rate, lifting action
92
Q

Life Cycle of a Thunderstorm

A
  • Lasts only about 30 minutes
  • Continuous thunderstorms are the result of a series of storms that develop in rapid succession without a break between
93
Q

Cumulus Stage of a Thunderstorm

A
  • Most cumulus clouds don’t grow into thunderstorms
  • Strong updraft is required to grow cloud into Towering Cumulus
  • If air is unstable, updraft may exceed 3000’ per minute
  • Water droplets grow to rain drop size but remain suspended by updrafts
  • Lasts about 10 minutes
94
Q

Mature Stage of a Thunderstorm

A
  • Appearance of precipitation indicates mature stage
  • Buildup can reach 60,000 ft
  • Updrafts to 6000’ per minute, can carry water droplets up into freezing areas
  • After droplets grow large enough to fall they take cold air down with them creating a downdraft, up to 2000’ per minute
  • Violent Turbulence in up and down drafts
  • Top forms anvil shaped cloud, created by updrafts
  • Lightning, downbursts, gust front, wind shear, hail, tornadoes are all possible
  • Lasts 15-20 minutes
95
Q

Dissipating Stage of a Thunderstorm

A
  • As the rain falls, it cools the lower part of the cloud and it loses energy
  • Downdrafts spread throughout the cloud except near the top
  • Motion is mostly downward
  • Sometimes strong gusts during this phase
  • Rain ceases, still some lightning
96
Q

Types of Thunderstorms - Air Mass

A
  • Convective lift
  • Singly, or in clusters on hot, humid summer days
  • Tend to be scattered
97
Q

Types of Thunderstorms - Frontal

A
  • Usually cold front, but also possible at warm front
  • Often form a line that may be hundreds of miles long
  • Often embedded in other clouds
98
Q

Types of Thunderstorms - Orographic

A

Air is forced upward by hills or mountains

99
Q

Thunderstorm Weather - Wind Shear

A
  • Found on all sides of the cell
  • In the down draft under the cell
  • In the gust front ahead of storm
100
Q

Thunderstorm Weather - Gust Front

A
  • At the mature stage, strong downdrafts spread out ahead of storm
  • Similar to a miniature cold front
  • Can change wind direction 180º and speed by 50 knots in a matter of seconds
101
Q

Thunderstorm Weather - Downburst

A
  • Strong downdraft of cold air pouring out of the cloud base capable of damaging winds on the ground
  • Spreads out rapidly
  • Often occurs in the dissipating stage
  • Can be wet or dry
102
Q

Thunderstorm Weather - Macroburst

A

Downburst at least 2.5 NM in diameter lasting 5-20 minutes

103
Q

Thunderstorm Weather - Microburst

A
  • Downburst smaller size than macroburst
  • Single Thunderstorm cell
  • May contain Virga
104
Q

Thunderstorm Weather - Hazards

A
  • Up to 6000’ per minute downdrafts
  • Gusts to 80 knots
  • Change direction and speed rapidly
  • Up to 20 miles from the storm
105
Q

Thunderstorm Weather - Shelf Cloud

A
  • Area of strong downdraft wind and outflow, moving away from main precipitation area
  • Form near leading edge of thunderstorm or under rain-free cloud base
  • Long wedge shaped clouds associated with the gust front
  • Often confused with a wall cloud
106
Q

Thunderstorm Weather - Wall Cloud

A
  • Signifies the area of strongest updraft
  • Lowering cloud attached to the rain-free base
  • Rotation of the persistent low cloud may be observed
  • Most likely area for funnel cloud or tornado development
107
Q

Thunderstorm Weather - Tornado

A

Violently rotating column of air descending from a thunderstorm in contact with the ground

108
Q

Thunderstorm Weather - Funnel Cloud

A

Rotating funnel shaped cloud extending from the base of a thunderstorm but not touching the ground

109
Q

Thunderstorm Weather - Hail

A
  • Severe hazard
  • Mature Stage
  • Need strong updrafts into the freezing layer
110
Q

Thunderstorm Weather - Lightning

A
  • Up and down drafts generate static charges within the cloud
  • When built up enough energy they discharge either within the cloud, cloud to ground, or cloud to cloud
111
Q

Thunderstorm Weather - Thunder

A
  • Noise from lightning discharge
  • Time difference between lightning and thunder indicates how far away the storm is
112
Q

Thunderstorm Weather - Icing

A

At or above the freezing level in heavy turbulence during the mature stage

113
Q

Thunderstorm Weather - Pressure change

A

Falls rapidly ahead of storm, rises quickly when rain starts and returns to normal as storm subsides

114
Q

Thunderstorm Dangers - Turbulence

A
  • Up and down drafts in and under the cloud
  • Up to 20 miles away from cloud
  • Loss of control, structural damage
115
Q

Thunderstorm Dangers - Lightning

A
  • Radio Interference
  • Lightning Blindness
  • Lightning Strike
  • Structural Damage, electrical damage, possibly ignite fuel vapors
116
Q

Thunderstorm Dangers - Hail

A

Structural Damage

117
Q

Thunderstorm Dangers - Icing on Airframe

A

Aircraft Performance

118
Q

Thunderstorm Dangers - Pressure Change

A

Performance of the Altimeter

119
Q

Thunderstorm Dangers - Rain

A
  • Contaminate wing surfaces
  • Reduce and distort visibility
  • Hydroplaning on runway
120
Q

Thunderstorm Dangers - Strong Winds

A
  • Abrupt changes in speed and direction
  • Wind shear, change head wind to tail wind
  • Rising air being sucked into the storm forms a vortex, may create a tornado
121
Q

Thunderstorm Avoidance

A
  • DO NOT attempt to penetrate any thunderstorm
  • Stay 5-20 miles away depending on size of storm
  • Try to fly around the right side
  • Do not take off or land in vicinity for possible downbursts, Virga, and gust front
  • Don’t fly under
  • Reduce to maneuvering speed
122
Q

Thunderstorm Detection - Lightning Detector

A
  • Detects electromagnetic discharge
  • Plots direction and range of every discharge within 200 mile radius
  • Does not detect rain
123
Q

Thunderstorm Detection - Weather Radar

A
  • Detects rain fall
  • Sees only ahead in a narrow band
  • Plots direction, range, and intensity of rain
124
Q

Weather Signs - Look For Cloudy Unsettled Weather

A
  • Barometer falling
  • Temp at night higher than usual
  • Clouds move in different directions at different heights
  • Cirrus clouds increasing
125
Q

Weather Signs - Look For Steady Precipitation

A
  • Signs of unsettled weather
  • Wind is South or Southeast and pressure falling
  • Wind is Southeast to Northeast and pressure falling
  • Thunderstorms develop with South or Southeast wind
126
Q

Weather Signs - Look For Showers

A
  • Thunderstorms develop with westerly wind
  • Cumulus clouds develop rapidly in early afternoon in spring or summer
127
Q

Weather Signs - Look For Clearing

A
  • Barometer Rises
  • Wind shifts to west or northwest
  • Temperature falls
128
Q

Weather Signs - Look For Continued Bright Weather

A
  • Look directly at sunset
  • Barometer is steady or rising slowly
  • Clouds decrease in later afternoon
  • Morning fog breaks within 2 hours after sunrise
  • Light breeze form west or northwest
  • Red sunset
129
Q

Weather Signs - Look For Higher Temperatures

A
  • Barometer falls
  • May be clouds that result in cooler weather in summer
  • Wind changes away from north or west’
  • Morning sky is clear except barometer high or rising in winter, strong wind from north or west
130
Q

Weather Signs - Look For Lower Temperatures

A
  • Wind Changes from southwest to west or from west to northwest or north
  • Clearing skies
  • Barometer rises in winter
  • Snow with a West or North Wind
  • Pressure is low or falling rapidly, wind East or Northeast changing slowly to North

AVIA 101 - FM1 (17 decks)

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