Cdc Volume 2 Set 2

Front 1

Which term defines a change in state from a solid to a gas?

Back 1

Sublimation.

Front 2

What changes of state absorb heat from the surrounding environment?

Back 2

Vaporization, fusion, and sublimation.

Front 3

What is the most efficient method of cloud droplet growth?

Back 3

Collision and coalescence.

Front 4

What term is used to define the process where the outer edge of the cloud mixes with air outside of the cloud?

Back 4

Dry-air entrainment.

Front 5

Which cloud forecasting tool is biased towards climatology (average conditions), and may not be accurate during abnormal conditions?

Back 5

Model output statistics.

Front 6

What is the main difference in forecasting the occurrence of convective or cumuliform clouds versus stratus clouds?

Back 6

Atmospheric stability.

Front 7

You would not expect stratus clouds to form when

Back 7

The curvature is anticyclonic.

Front 8

A very narrow band of clouds associated with a cold front may indicate the

Back 8

700mb contours are perpendicular to the surface cold front.

Front 9

The type and intensity of precipitation observed at the earth's surface is related to the thickness of the cloud aloft and particularly to the

Back 9

Temperatures in the upper part of the cloud.

Front 10

With a quasistationary front in the southern United States under a broad west or southwest flow aloft and a weak surface low, the snow rain zone becomes

Back 10

Elongated in the direction of the upper-level current with precipitation rates stretching over long periods.

Front 11

Which condition increases the probability of fog formation?

Back 11

Advecting a warm, moist air mass over a cold surface.

Front 12

Which condition decreases the likelihood of fog formation?

Back 12

Increased temperature and decreased moisture content.

Front 13

What type of air mass causes a persistent type of continental high-inversion fog to occur in valleys?

Back 13

Maritime polar air.

Front 14

Which visibility restriction is the most localized?

Back 14

Smoke.

Front 15

What would the estimated low-level wind speed be, in knots from satellite imagery displaying arc-shaped open-cell cumulus clouds?

Back 15

21 to 30.

Front 16

If no inversion is present, forecast the maximum surface wind gusts to be

Back 16

80 percent of the 5,000-foot wind speed.

Front 17

In forecasting frontal winds, the deepening or filling of a frontal trough

Back 17

Increases or decreases the winds.

Front 18

Which tertiary circulation is associated with mountain-wave turbulence?

Back 18

Foehn wind.

Front 19

Object A has a temperature of 49 degrees celsius, object B has a temperature of 65 degrees celsius and object C has a temperature of 88 C. How might thermal energy be transferred between the three objects?

Back 19

B and C transfer to A.

Front 20

How many degrees are there between the freezing point and the boiling point on the Kelvin temperature scale?

Back 20

100.

Front 21

What type humidity is another expression of mixing ratio?

Back 21

Absolute.

Front 22

Which forecasting tool provides a summary of monthly and annual climatic data for a station?

Back 22

Operational Climatic Data Summary (OCDS).

Front 23

Surface heating occurs more rapidly

Back 23

With a stable lapse rate.

Front 24

A heat wave over the Midwestern and eastern part of the United States develops when a

Back 24

Long-wave trough stagnates over the Rockies and a long-wave ridge lays over the east coast.

Front 25

Which condition must exist for the development of a cold wave over the United States?

Back 25

Movement of a low eastward from the Continental Divide.

Front 26

How many hours can the global forecast system (GFS) long range forecast predict up to?

Back 26

384.

Front 27

If the temperature through a vertical column is warmer than standard, then the air density is

Back 27

Less than standard and a pilot must fly higher to reach a given altitude.

Front 28

How is the difference (D) -value calculated?

Back 28

True altitude minus standard altitude.

Front 29

What values do you need to compute the pressure altitude?

Back 29

Field elevation and altimeter setting.

Front 30

Density altitude is the

Back 30

Altitude at which a given density is found in the standard atmosphere.

Front 31

What two parameters are used to compute density altitude?

Back 31

Pressure and virtual temperature.

Front 32

Turbulence should not be anticipated in areas of

Back 32

Inflow in a digging jet.

Front 33

As a general rule, the effects of turbulence for a fixed-wing aircraft are increased with decreased

Back 33

Weight of the Aircraft.

Front 34

Roll or rotor clouds form

Back 34

Parallel to the mountain ridge and are located on the leeside.

Front 35

The most dangerous features of mountain wave clouds are the turbulence in the cap and

Back 35

Rotor cloud.

Front 36

All turbulence not thermally induced or associated with convective activity is classified as

Back 36

Clear-air.

Front 37

How can an aircrew avoid the effects of wake turbulence?

Back 37

Land beyond the touchdown point of the leading aircraft, lift off ahead of the liftoff point of a leading aircraft, and fly above leading aircraft.

Front 38

Which type of aircraft icing occurs in cumuliform clouds and is hard, glossy, and heavy?

Back 38

Clear.

Front 39

What is the intensity for an in-flight icing when deicing or anti-icing equipment fails to reduce or control the hazard and immediate diversion is necessary?

Back 39

Severe.

Front 40

How does in-flight icing on an airplane effect drag and the ability to lift when considering airfoil, respectively?

Back 40

Increases; Decreases.

Front 41

Which ice protection system is activated before the aircraft enters the icing condition?

Back 41

Anti-icing equipment.

Front 42

What icing intensity corresponds to freezing drizzle?

Back 42

Moderate.

Front 43

Which item is not a guidance tool or product for icing?

Back 43

Meteorological satellite (METSAT) imagery.

Front 44

What type of icing, if any, will an aircraft encounter if icing conditions are favorable and flying above 12,000 feet in a stratiform cloud?

Back 44

Rime.

Front 45

With a frontal system, the greatest icing occurs when the updrafts exist. The only exception to this rile is when icing is associated with

Back 45

Freezing precipitation.

Front 46

How would an aircraft be affected during the landing if it were flying from a headwind over the outer marker to a tailwind over the runway?

Back 46

Indicated airspeed decreases, and aircraft drops below the glide scope.

Front 47

How does the upper portion of a thunderstorm gust front compare to the surface portion?

Back 47

Precedes the surface portion by one or two miles.

Front 48

When forecasting weather you would expect low-level wind shear when

Back 48

Sustained surface wind is 10 knots or greater and the difference between the gradient wind speed and twice the surface wind speed is 20 knots or greater.

Front 49

The combination of cold air aloft and warm surface air can produce a

Back 49

Sharp lapse rate and an unstable atmosphere.

Front 50

In the continental United States, what months of the year are the best for severe thunderstorm activity?

Back 50

March through September.

Front 51

What are the conditions necessary for the development of tornadoes, severe thunderstorms, and their associated destructive phenomena?

Back 51

Unstable atmosphere, large quantities of moisture, strong mid-level winds, surface-based lifting mechanism, and a favorable WBZ

Front 52

What kind of thunderstorm is the closest to a three-stage, non serve thunderstorm?

Back 52

Air-mass.

Front 53

What stage of a non-severe thunderstorm occurs when precipitation is suspended aloft?

Back 53

Cumulus.

Front 54

Hail size is dependent on the

Back 54

Strength of the updraft core and the length of fall from the freezing level to the surface.

Front 55

Thunderstorms that appear to move to the right of mid-level winds are called

Back 55

Discrete propagation.

Front 56

Which action is associated with the gust front?

Back 56

Forward flank downdraft.

Front 57

Super cells splitting into two separate cells is caused by the environmental wake flow cutting into the

Back 57

Downwind side of the updraft core and precipitation "loading" in the mid-levels above the updraft core.

Front 58

What is the one requirement that must always be present in order for tornadoes to form?

Back 58

Appreciable lifting.

Front 59

In what tornado-producing air structure do tornadoes most frequently occur in families, with paths that are commonly long and wide?

Back 59

Type I, Great plains.

Front 60

What is the most common severe weather phenomena associated with the type E, major cyclone severe weather producing synoptic pattern?

Back 60

Hail.

Front 61

Where does one of the two well-defined northwest flow frequency aces extend?

Back 61

Eastern North Dakota to southwestern
Pennsylvania.

Front 62

What type of destructive summertime mesoscale system is associated with northwest flow outbreaks?

Back 62

Derecho.

Front 63

On the average, how many hours elapse between the first thunderstorm development of a mesoscale convective complex and the time it begins to decay?

Back 63

16 1/2

Front 64

What upper-level (500 millibars [mb] to 200mb) zone pattern is extremely important to identify over a mesoscale convective complex genesis region?

Back 64

Difluence.

Front 65

What is the peak month for haboob dust storms to occur based on climatology?

Back 65

June.

Front 66

What are the two primary concerns when forecasting a haboob dust storm?

Back 66

Visibility and wind speed.

Front 67

The typical hurricane season extends from

Back 67

June through November

Front 68

A fairly accurate sign of an approaching tropical cyclone is

Back 68

A swell that comes in a series of waves with a long interval between crests.

Front 69

The difference between the actual sea-surface elevation and the predicted astronomical sea-surface elevation is known as

Back 69

Storm surge.

Front 70

Warm advection in the lower levels during snow-producing situations

Back 70

Can suggest increased snow potential.

Front 71

What direction and speed does a non-occluding baroclinic low that produces heavy snow usually move

Back 71

East-northeast at approximately 25kts or greater

Front 72

A severe blizzard contains winds

Back 72

>=50kts and temperatures <=10F

Front 73

When forecasting precipitation type, the layer between the surface and what millibar level is determining factor in terms of temperature-moisture
distribution?

Back 73

700

Front 74

What is the threshold value, in knots, for strong nonconvective winds?

Back 74

>34

Front 75

What is the primary concern when forecasting
shamals?

Back 75

Source region.

Front 76

Why does the isobar spacing on a Skew-T chart increase from the bottom to the top of the chart?

Back 76

Accounts for the decrease in density of the
atmosphere with height,

Front 77

Potential temperature is the temperature an air sample would have if its pressure were increased to

Back 77

1,000 millibars (mb) in a dry adiabatic process.

Front 78

The lifted condensation level is the intersection obtained on the Skew-T chart between the

Back 78

Mixing ration line and dry adiabat.

Front 79

A second method for finding the convective condensation level was developed to give increased accuracy in

Back 79

Severe weather forecasting.

Front 80

To determine the mixing condensation level, you must first determine the

Back 80

Top of the mixing level.

Front 81

Convective temperature is the temperature that surface air must reach to initiate convective currents that will

Back 81

Extend high enough for the air to become
saturated.

Front 82

What temperature can be obtained by following a dry adiabat parcel down from the convective condensation level to the point where the dry adiabat parcel intersects the isobar representing the surface pressure?

Back 82

Convective.

Front 83

The height at which a parcel of air is lifted, first becomes warmer (less dense) than the environment is the

Back 83

Level of free convection.

Front 84

What indicates a temperature increase with an increase in height indicating a negative lapse rate in a layer of the atmosphere?

Back 84

Inversion.

Front 85

What is the potential for thunderstorms with a convective available potential energy (CAPE) of 2250 joule per kilogram (J/kg)?

Back 85

Moderate.

Front 86

What is the potential for thunderstorms with a cross total of 30 and a vertical total of 23?

Back 86

Scattered severe.

Front 87

Tornado occurrences are grouped in severe
weather threat index values of

Back 87

Greater than 400

Front 88

The K-index is a measure of a thunderstorm's

Back 88

Potential.

Front 89

What index is used to assess the instability of the 850 millibar (mb) parcel?

Back 89

Showalter stability.

Front 90

The season of maximum hail occurences coincides with

Back 90

The season of maximum thunderstorms.

Front 91

What percentage of hail occurrences in flight is attributed to have happened under overhanging clouds between 10,000 and 20,000 feet?

Back 91

85.

Front 92

What is the cloud depth ratio if the convective condensation level is at 770 millibars (mb), the freezing level at 550mn, and the equilibrium level at 270mb?

Back 92

0.44.

Front 93

What is considered the optimum wet bulb zero (WBZ) height, in feet, above the terrain for hail?

Back 93

8,000.

Front 94

What must be determined as the first step in forecasting the size of hail?

Back 94

Convective condensation level.

Front 95

In using the T1 method of forecasting maximum wind gusts, the warmest point on the inversion is used to determine the T1 if surface convection does not dissipate the inversion and if that warmest point is within how many millibars (mb) of the surface?

Back 95

150-200.

Front 96

What preconditions must exist to make the T2 method over forecast maximum gusts?

Back 96

The thunderstorm must pass over the forecast point and moderate to heavy rain must occur.

Front 97

A veering wind in the vertical suggest a

Back 97

Warm air advection not associated with a warm front.

Front 98

When forecasting turbulence in convective clouds below 9,000 feet what determines the severity of the turbulence?

Back 98

Temperature difference between the moist adiabat and the free-air temperature curve.

Front 99

When forecasting turbulence in convective clouds above 9,000 feet, where is the central portion of the most turbulent area?

Back 99

Where the maximum temperature difference between the moist adiabat and the free-air temperature is.

Front 100

In severe weather forecasting, the best time period to forecast a Skew-T sounding is during the

Back 100

Maximum heating.