Question 163-1 : Which of the following meteorological phenomenon indicates upper level instability which may lead to thunderstorm development ? [ Formation assignment ]

Question 163-2 : Which type of fog is likely to form when air having temperature of 15°c and dew point of 12°c blows at 10 knots over a sea surface having temperatures of 5°c ?

Advection fog.

Advection fog warm moist air mass moving over a cold surface without too much windradiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-3 : What type of fog is most likely to form over flat land during a clear night with calm or light wind conditions ?

Radiation.

Radiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-4 : Which types of clouds are typical evidence of stable air conditions ?

St as.

Strat = stability

Question 163-5 : Which one of the displayed cloud forms is representative of altocumulus lenticularis 295 ?

N°2.

Question 163-6 : Which one of the displayed cloud forms is representative of a cumulonimbus capillatus 296 ?

N°4.

As the cumulonimbus cloud grows in size it may turn into a cumulonimbus capillatus which means that it gains a fibrous edged top 640a clearly developed cumulonimbus capillatus displaying the classic anvil shape

Question 163-7 : A plain in western europe with an average height of 500 m 1600 ft above sea level is covered with a uniform sc layer of cloud during the summer months at what height above the ground is the base of this cloud to be expected ?

1500 7000 ft above ground.

503stratocumulus are low level cloudsduring the summer months the land warms up and the cloud base goes up this is the reason why sc will not be found below 1500 ft

Question 163-8 : A plain in western europe with an average height of 500 m 1600 ft above sea level is covered with a uniform cc layer of cloud during the summer months at what height above the ground is the base of this cloud to be expected ?

15000 35000 ft above the terrain.

Cirrocumulus cc are high level clouds 503the base of the layer can be expected between 15000 ft up to 35000 ft

Question 163-9 : Which of the following cloud types is found at high levels ?

Ci.

503

Question 163-10 : Which of the following cloud types is a medium level cloud ?

As.

503

Question 163-11 : Under which of these conditions is radiation fog most likely to form ?

Little or no cloud.

Radiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-12 : Which of the following is most likely to lead to the formation of radiation fog ?

Heat loss from the ground on clear nights.

Radiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-13 : Of the four radio soundings select the one that indicates low stratus 298 ?

N°3.

When temperature and dew point are equals the air is satured and condensed water droplets will form cloud or fog radio sounding n°2 indicates ground fog at the surface radio sounding n°3 indicates that a layer of cloud is present above the surface

Question 163-14 : In which of the following metar reports is the probability of fog formation in the coming night the highest ?

201850z 15003kt 6000 sct120 0504 q1032 becmg 1600 br=.

Light wind below 5 kt little or no cloud clear night only one degree between temperature and dew pointvisibilty will fall from 6000 m to 1600 m and br mist indicates moist airthis conditions will lead to the formation of radiation fog moist air over land with heat loss from the ground on clear nights

Question 163-15 : Which airport is most likely to have fog in the coming night 302 ?

Lszh.

Radiation fogs occur at night and usually do not last long after sunrise radiation fog is common in autumn and early winter north hemisphere radiation fog is formed by the cooling of land after sunset by thermal radiation in calm conditions with clear skythe cool ground produces condensation in the nearby air by heat conduction in the next 8 hours ekch engm and essa will be covered by the second perturbation arriving from the west with winds rains and cloudsonly zurich airport lszh will remains clear from the bad weather area allowing radiation fog development

Question 163-16 : Which of the following cloud types are most likely to produce light to moderate icing when they are not subject to orographic lifting and consist of supercooled cloud droplets ?

Altocumulus and altostratus.

Cirrocumulus and cirrostratus are high altitude clouds no supercooled cloud dropletscumulonimbus it produces light moderate and severe icingit remains only the 'altos' altocumulus and altostratus

Question 163-17 : Altostratus clouds are classified as ?

Medium level clouds.

503

Question 163-18 : A cumulonimbus cloud at mid latitudes in summer contains ?

Ice crystals water droplets and supercooled water droplets.

Question 163-19 : Strongly developed cumulus clouds are an indication of ?

Instability in the atmosphere.

Question 163-20 : Clouds classified as being low level are considered to have bases from ?

The surface to 6500 ft.

503

Question 163-21 : Which of the following are medium level clouds ?

Altostratus and altocumulus.

503

Question 163-22 : Cumulus clouds are an indication for ?

Up and downdrafts.

It means instability

Question 163-23 : A generally grey cloud layer with fairly uniform base and uniform appearance which may give drizzle or snow grains when the sun is visible through the cloud the outline is clearly discernible sometimes it appears in the form of ragged patcheswhat type of cloud is being described ?

Stratus.

Question 163-24 : The presence of altocumulus castellanus indicates ?

Instability in the middle troposphere.

Question 163-25 : In an area of converging air in low level ?

Clouds can be formed.

563divergence in the upper air means convergence on the ground this a low pressure area and clouds may appears above it

Question 163-26 : When the temperature and dew point are less than one degree apart the weather conditions are most likely to be ?

Fog or low cloud.

Question 163-27 : The morning following a clear calm night when the temperature has dropped to the dewpoint is likely to produce ?

Radiation fog.

Radiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-28 : Advection fog can be formed when ?

Warm moist air flows over a colder surface.

Advection fog warm moist air mass moving over a cold surface without too much windradiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-29 : Steaming fog arctic sea smoke occurs in air ?

With cold mass properties.

Steam fog also known as steaming fog evaporation fog frost smoke or arctic sea smoke occurs when evaporation takes place into cold air lying over warmer water 569it is named by analogy with the condensed vapor or steam which appears above water which is heated invisible vapor is given off from the water but is almost immediately recondensed as it comes into contact with the colder air the air has to be much colder than the water so that convection currents develop formation also requires that there is a marked surface temperature inversion in the air before it moves over the sea or inland water bodies so as to preclude the lapse rate becoming unstable through a deep layer a low air temperature typically 0°c or below so that a comparatively small amount of moisture can produce supersaturation otherwise the heating process will outweigh the tendency towards saturationbecause of these requirements this type of fog is usually only formed over water surfaces near to a source of cold air such as frozen ground or ice sheets in polar regions one classic occurrence is following the sudden break up of sea ice to expose relatively warm water in the steep sided fjords along parts of the icelandic and norwegian coasts and similar environments elsewhere steam fog may reach a depth of 500 feet or more and drift over adjacent land areas whilst relatively rare in temperate latitudes cold air which collects in and then drifts down large river valleys and out over a relatively warm sea surface in very light wind conditions can occasionally lead to the formation of smaller and much shallower areas of this type of fog in winter

Question 163-30 : Frontal fog is most likely to occur ?

In advance of a warm front.

The passage of a warm front can be associated with areas of fog the types of fog just in advance of a warm front is frontal fog and just after the passage is advection fog frontal fog is caused by the additional moisture in the air due to the evaporation of rain or drizzlethe different types of fog radiation fog forms due to surface cooling at night in a light windsteaming fog is the same as arctic smoke or sea smoke and is caused by cold air moving over a warm surfaceadvection fog forms when warm humid air flows over a cold surfacefrontal fog is most likely to occur in advance of a warm front it is due to the rain falls from the warm air into the cold air

Question 163-31 : Freezing fog exists if fog droplets ?

Are supercooled.

Question 163-32 : Which of the following circumstances most favour the development of radiation fog ?

Moist air over land during clear night with little wind.

Question 163-33 : Fallstreaks or virga are ?

Water or ice particles falling out of a cloud that evaporate before reaching the ground.

2542

Question 163-34 : The range of wind speed in which radiation fog is most likely to form is ?

Below 5 kt.

Question 163-35 : At the top of orographic waves in mountainous regions the cloud most likely to be encountered is ?

Altocumulus lenticularis.

433 2540

Question 163-36 : A cumulus congestus is ?

A cumulus that is of great vertical extent.

Question 163-37 : Clouds in patches sheets or grey or whitish layers made up of elements resembling large pebbles or rollers together or not and always clear of the ground are ?

Stratocumulus.

597

Question 163-38 : In mid latitudes the tops of cumulus are often limited by ?

A temperature inversion.

Their growth is usually limited by a temperature inversion which is marked by the unusually uniform height of the clouds also called fair weather cumulus

Question 163-39 : Of what does lenticular cloud provide evidence ?

Mountain waves.

Question 163-40 : The formation of morning fog before sunrise is possible if ?

Air temperature and dew point are equal or close to one another.