NBHWC FINAL EXAM
QUESTIONS AND COMPLETE
ANSWERS
QUESTIONS AND ANSWERS
In the atmosphere, cloud condensation nuclei are ______ abundant than ice-forming nuclei.
ANSWER -More
Where there is an abundance of hygroscopic nuclei in the atmosphere, clouds are likely to
develop at relative humidities ______ 100%. ANSWER -Under
If cumulus clouds (puffy clouds that build vertically) continue to develop to great altitudes,
the atmosphere is ANSWER -Unstable
Lee-wave clouds form ______ of a mountain range. ANSWER -Downwind
Overnight radiational cooling of clear air may cause temperatures to reach saturation with
stable conditions to form ______ fog. ANSWER -Radiation
The water droplets and ice crystals that make up clouds are always falling relative to the
air, yet the clouds themselves may not be falling relative to the Earth's surface. This
happens because clouds are most likely to be located where ______ prevail. ANSWER -
Updrafts
,Water in solid or liquid form that falls from clouds to the Earth's surface is known as
ANSWER -Precipitation
Which one of the following particles has the greatest terminal velocity in still air?
ANSWER -Rain drop
Cloud droplets can cool to temperatures well below 0 °C (32 °F) without freezing. When
these so-called supercooled droplets coexist with ice crystals in the same cloud, the ______
grow in size. This is the basis of the Bergeron-Findeisen process that is responsible for the
formation of most precipitation. ANSWER -Ice crystals
At least some of the water (in the liquid or solid form) falling from a cloud vaporizes as it
passes through ______ air below the cloud base. If the water completely vaporizes before
reaching the Earth's surface, the shaft of falling liquid or ice particles is known as virga.
ANSWER -Unsaturated
Freezing rain (or drizzle) occurs when falling water drops are ______; thus, drops partially
freeze when they strike cold surfaces. ANSWER -Supercooled
Acid rain (or snow) occurs when the pH of the precipitation is less than ANSWER -5.6
For a weather radar operating in the reflectivity mode, the strongest echoes are produced
by ANSWER -Hail
As a general rule-of-thumb, on average, 13 inches of snow will melt down to 1 inch of liquid
water. Therefore, a 33-inch snowfall will produce approximately ______ inches of liquid.
ANSWER -2.5
Remote sensing of precipitation amounts over the vast areas of tropical oceans is possible
with data from the ______ satellite. ANSWER -GPM
A mass of cold, dry air is ________ a mass of warm, humid air. Consequently, warmer
(lighter) air is often forced to rise above the sloping frontal surface overlying colder (denser)
air. ANSWER -Denser than
,Ascending unsaturated (clear) air ________, cooling at about 10 Celsius degrees per 1000
meters of ascent (5.5 Fahrenheit degrees per 1000 feet). ANSWER -Expands
The warmer air rising above the frontal surface expands and cools as it ascends, and its
relative humidity ________. If saturation is achieved, clouds develop and from those clouds,
rain or snow may fall. ANSWER -Increases
The relative humidity of saturated (cloudy) air is ________. ANSWER -100%
Clouds (and perhaps precipitation) can develop in the ascending branch of a convection
current, along a front, and up the windward slopes of a mountain range. The ascending
branch of a convective current may produce an upwardly billowing cloud known as a
________ cloud. For a review of cloud types and their development, see Chapter 7 of the
AMS Weather Studies textbook. ANSWER -Cumulus
Prevailing winds blow from west to east across most of North America. Winds that blow
onshore from the Pacific Ocean are forced up the windward slopes of the Cascade Mountain
Range in the Pacific Northwest. Hence, the heaviest precipitation falls on the ________
slopes of the Cascades. ANSWER -Western
The cold front extending from the low-pressure center was advancing generally toward the
________. ANSWER -East
Portland, Oregon, located just behind the front, had a temperature of 59 °F and dewpoint of
52 °F at map time. Although this surface air was not saturated, the present weather symbol
in the station model was two dots signifying ________ was occurring. ANSWER -Rain
The advancing front ________ have provided a lifting mechanism for the air leading to
clouds and precipitation. ANSWER -Would
Radar shadings indicate where the NWS national network of Doppler radars was detecting
precipitation. The intensities of the echoes according to the scale at the left edge of the map
were related to precipitation rates. From the map display, precipitation was broadly located
generally: ________. ANSWER -In both of these (in a curved band to either side of the
coastal cold front & widely spread in eastern Washington and Oregon, Idaho and western
Montana)
, Precipitation was also scattered ________. ANSWER -Over the western Great Lakes ahead
of a cold front & southeast of Florida associated with a tropical disturbance
Bright white shadings in the infrared image ________ align east of and along the location of
the cold front in the Northwest in Figure 1. ANSWER -Did
The frontal symbols in Figure 1 indicated the direction of the movement of the cold front
and implied the future motion of the clouds to be ________. ANSWER -Moving directly
toward the mountains which are oriented generally north-south along the coast
The movement of the frontal system and the direction of travel in relation to the orientation
of the mountains ________ combine to enhance the lifting of the humid air. ANSWER -
Would
The bright satellite shading of high cloud tops moving onto the Northwest coast ________
approximately coincide with the surface map's display of precipitation as shown by the radar
shadings. ANSWER -Did
The greatest precipitation amounts are shown as several white specks within purple blobs
in Washington, Oregon and northern California. These shadings of the heaviest
precipitation ________ generally occur where precipitation had been indicated by radar
echoes in Figure 1 and bright white cloud tops of Figure 2. While the surface map is a
single time, the conditions depicted in Figure 3 were representative of the several days
where multiple storm systems passed across the same area. ANSWER -Did
The intense red shadings of heavy precipitation ________ generally extend along the coast
and midway north-south through Washington and Oregon where mountainous terrain
existed. ANSWER -Did
According to the precipitation scale, the pink shade covered extensive areas where the
weekly total precipitation was at least ________ inches with the isolated white spots
receiving 20 inches or more. ANSWER -10.0
In this example, the actual winds circulating around the mesocyclone all have the same
speed, as shown by arrows whose lengths are ________. ANSWER -The same
QUESTIONS AND COMPLETE
ANSWERS
QUESTIONS AND ANSWERS
In the atmosphere, cloud condensation nuclei are ______ abundant than ice-forming nuclei.
ANSWER -More
Where there is an abundance of hygroscopic nuclei in the atmosphere, clouds are likely to
develop at relative humidities ______ 100%. ANSWER -Under
If cumulus clouds (puffy clouds that build vertically) continue to develop to great altitudes,
the atmosphere is ANSWER -Unstable
Lee-wave clouds form ______ of a mountain range. ANSWER -Downwind
Overnight radiational cooling of clear air may cause temperatures to reach saturation with
stable conditions to form ______ fog. ANSWER -Radiation
The water droplets and ice crystals that make up clouds are always falling relative to the
air, yet the clouds themselves may not be falling relative to the Earth's surface. This
happens because clouds are most likely to be located where ______ prevail. ANSWER -
Updrafts
,Water in solid or liquid form that falls from clouds to the Earth's surface is known as
ANSWER -Precipitation
Which one of the following particles has the greatest terminal velocity in still air?
ANSWER -Rain drop
Cloud droplets can cool to temperatures well below 0 °C (32 °F) without freezing. When
these so-called supercooled droplets coexist with ice crystals in the same cloud, the ______
grow in size. This is the basis of the Bergeron-Findeisen process that is responsible for the
formation of most precipitation. ANSWER -Ice crystals
At least some of the water (in the liquid or solid form) falling from a cloud vaporizes as it
passes through ______ air below the cloud base. If the water completely vaporizes before
reaching the Earth's surface, the shaft of falling liquid or ice particles is known as virga.
ANSWER -Unsaturated
Freezing rain (or drizzle) occurs when falling water drops are ______; thus, drops partially
freeze when they strike cold surfaces. ANSWER -Supercooled
Acid rain (or snow) occurs when the pH of the precipitation is less than ANSWER -5.6
For a weather radar operating in the reflectivity mode, the strongest echoes are produced
by ANSWER -Hail
As a general rule-of-thumb, on average, 13 inches of snow will melt down to 1 inch of liquid
water. Therefore, a 33-inch snowfall will produce approximately ______ inches of liquid.
ANSWER -2.5
Remote sensing of precipitation amounts over the vast areas of tropical oceans is possible
with data from the ______ satellite. ANSWER -GPM
A mass of cold, dry air is ________ a mass of warm, humid air. Consequently, warmer
(lighter) air is often forced to rise above the sloping frontal surface overlying colder (denser)
air. ANSWER -Denser than
,Ascending unsaturated (clear) air ________, cooling at about 10 Celsius degrees per 1000
meters of ascent (5.5 Fahrenheit degrees per 1000 feet). ANSWER -Expands
The warmer air rising above the frontal surface expands and cools as it ascends, and its
relative humidity ________. If saturation is achieved, clouds develop and from those clouds,
rain or snow may fall. ANSWER -Increases
The relative humidity of saturated (cloudy) air is ________. ANSWER -100%
Clouds (and perhaps precipitation) can develop in the ascending branch of a convection
current, along a front, and up the windward slopes of a mountain range. The ascending
branch of a convective current may produce an upwardly billowing cloud known as a
________ cloud. For a review of cloud types and their development, see Chapter 7 of the
AMS Weather Studies textbook. ANSWER -Cumulus
Prevailing winds blow from west to east across most of North America. Winds that blow
onshore from the Pacific Ocean are forced up the windward slopes of the Cascade Mountain
Range in the Pacific Northwest. Hence, the heaviest precipitation falls on the ________
slopes of the Cascades. ANSWER -Western
The cold front extending from the low-pressure center was advancing generally toward the
________. ANSWER -East
Portland, Oregon, located just behind the front, had a temperature of 59 °F and dewpoint of
52 °F at map time. Although this surface air was not saturated, the present weather symbol
in the station model was two dots signifying ________ was occurring. ANSWER -Rain
The advancing front ________ have provided a lifting mechanism for the air leading to
clouds and precipitation. ANSWER -Would
Radar shadings indicate where the NWS national network of Doppler radars was detecting
precipitation. The intensities of the echoes according to the scale at the left edge of the map
were related to precipitation rates. From the map display, precipitation was broadly located
generally: ________. ANSWER -In both of these (in a curved band to either side of the
coastal cold front & widely spread in eastern Washington and Oregon, Idaho and western
Montana)
, Precipitation was also scattered ________. ANSWER -Over the western Great Lakes ahead
of a cold front & southeast of Florida associated with a tropical disturbance
Bright white shadings in the infrared image ________ align east of and along the location of
the cold front in the Northwest in Figure 1. ANSWER -Did
The frontal symbols in Figure 1 indicated the direction of the movement of the cold front
and implied the future motion of the clouds to be ________. ANSWER -Moving directly
toward the mountains which are oriented generally north-south along the coast
The movement of the frontal system and the direction of travel in relation to the orientation
of the mountains ________ combine to enhance the lifting of the humid air. ANSWER -
Would
The bright satellite shading of high cloud tops moving onto the Northwest coast ________
approximately coincide with the surface map's display of precipitation as shown by the radar
shadings. ANSWER -Did
The greatest precipitation amounts are shown as several white specks within purple blobs
in Washington, Oregon and northern California. These shadings of the heaviest
precipitation ________ generally occur where precipitation had been indicated by radar
echoes in Figure 1 and bright white cloud tops of Figure 2. While the surface map is a
single time, the conditions depicted in Figure 3 were representative of the several days
where multiple storm systems passed across the same area. ANSWER -Did
The intense red shadings of heavy precipitation ________ generally extend along the coast
and midway north-south through Washington and Oregon where mountainous terrain
existed. ANSWER -Did
According to the precipitation scale, the pink shade covered extensive areas where the
weekly total precipitation was at least ________ inches with the isolated white spots
receiving 20 inches or more. ANSWER -10.0
In this example, the actual winds circulating around the mesocyclone all have the same
speed, as shown by arrows whose lengths are ________. ANSWER -The same
