ATSC 113 - Snow Sports Exam preparation training
Questions and Answers 2025/2026
What is depth hoar? - correct answer Very large and angular snow
crystals that form near bottom of snow pack
What are rounded crystals? - correct answer Crystals that are produced
when temperature gradients are weak, which makes water vapour move
slowly and thus crystal growth happen slowly
When do rounded crystals form? - correct answer The opposite scenario
for faceting, where cloudy night-time conditions keep the snow surface
warmer, and inhibit the formation of near-snow-surface temperature
inversions in the air. (cold snow-surfaces can still happen if a cold air mass
is in place)
Deeper snowpacks
Why do facet/rounded crystals matter? - correct answer Generally, facet
crystals are weakly bonded, making snowpack more unstable and weak,
whereas rounded crystals make the snowpack stronger and more stable
What is a comfortable skiing temperature range? - correct answer A
comfortable range is about -8C to +3C, but any given person has a different
comfort range
The amount of heat your body produces will be different if you're skiing
harder (warmer) or going for an easy cruise (colder)
What are the primary and secondary hazards of cold temperatures? -
correct answer Frostbite and hypothermia are primary hazards, and wind
chill can make a given temperature feel much colder
,A secondary effect is with cold temperatures that can lead to a formation of
a weak snow layer near the surface, which after being buried by
subsequent storms, can lead to avalanches
What clothing should you wear in cold temperatures? - correct answer A
temperature of about -10C or lower is colder than a typical day, so you'd
want to bring
Additional warm layers (like down, synthetic down, fleece, or wool);
Consider putting chemical warmers in your boots and gloves
What are some associated hazards with unreasonably warm
temperatures? - correct answer Heat stroke, dehydration
What is snow melt? - correct answer Any time the temperature gets to 0°C
or above, snowmelt starts to become a factor for ski conditions and
avalanche danger.
When there is a prolonged period of above freezing overnight temperatures
for the first time in spring, wet slab avalanches become more likely.
What are snow pits? - correct answer 1-2 m deep holes dug in the snow
to analyze potential layers of concern; ie unstable sections of the snow
pack, by doing layer identification, snow crystal type, and hardness tests
What is the hand hardness test? - correct answer The hardness of a layer
related to the density and cohesiveness of the layer. This test is done by
applying light pressure to each snow pack layer, with hardness levels from
softest to hardest being: fist, four fingers, one finger, pencil, and knife.
(done in opposite order)
The last thing you are easily able to push into the layer is the hardness
rating of the layer
,What is a weakly-bonded snow layer? - correct answer Weak snow within
a snowpack that has undergone faceting, and has less density and fewer
bonds between crystals → weaker and less cohesive
Another type of weak layer is surface hoar, which forms at the surface of a
snow pack and becomes a weak layer once it's buried in snow
What is a strongly-bonded snow layer? - correct answer Strong snow
within a snowpack, or a strong layer, that is most commonly made up of old
stellar dendrites (picture-perfect looking snowflakes with branches) that are
now rounded crystals (a.k.a. Rounds).
What is a crust layer? - correct answer A layer that forms when a rain-on-
snow event occurs and the water-saturated snow freezes.
The crusts themselves don't usually fail but they may lead to failure. For
example, crusts can block the flow of water vapour within the snowpack,
causing a weak layer of facets to form immediately above them in the
snowpack.
What determines if the whole snowpack is stable/unstable? - correct
answer The relative strength of the layers, with a stronger/more dense
layer on top of a weaker/less dense layer being seen as unstable
What is storm snow? - correct answer Snow that is currently falling or
newly fallen within the last 48 hours, with instabilities that are typically
short-lived, lasting only 12-48 hours as the new snow rapidly settles
What is temperature inversion? - correct answer When temperature
increases with height for some layer of air within the troposphere.
, What does it mean of layers are statically stable? - correct answer When
a layer of cool air lies beneath a layer of warmer air (an inversion is
present)
What is valley cloud and flog? - correct answer When inversion traps
moisture within a valley (since stable air resists vertical motion)
What is capping inversion? - correct answer Inversion can occur
elsewhere within the troposphere (dashed green lines) and acts like a cap
or lid. Generally, air rising from below does not get any higher than the
inversion layer.
How does inversion occur? - correct answer Subsidence from high
pressure, or radiative cooling of the ground
What is subsidence? - correct answer Large scale sinking motions
associated with high pressure systems. As the air descends (at the dry
adiabatic lapse rate) and becomes drier
What is radiative cooling of the ground? - correct answer On clear calm
nights, the earth's surface radiates heat into space and cools, which makes
the air in contact with the surface cool down as-well
In the winter, the snow amplifies the effect of inversion and makes it lose
heat more quickly
End result is wintertime inversions in mountain valleys can be sustained for
weeks on end under persistent high pressure.
What is climate? - correct answer The prevailing weather conditions of a
region over a long time (ie 30 years)
Questions and Answers 2025/2026
What is depth hoar? - correct answer Very large and angular snow
crystals that form near bottom of snow pack
What are rounded crystals? - correct answer Crystals that are produced
when temperature gradients are weak, which makes water vapour move
slowly and thus crystal growth happen slowly
When do rounded crystals form? - correct answer The opposite scenario
for faceting, where cloudy night-time conditions keep the snow surface
warmer, and inhibit the formation of near-snow-surface temperature
inversions in the air. (cold snow-surfaces can still happen if a cold air mass
is in place)
Deeper snowpacks
Why do facet/rounded crystals matter? - correct answer Generally, facet
crystals are weakly bonded, making snowpack more unstable and weak,
whereas rounded crystals make the snowpack stronger and more stable
What is a comfortable skiing temperature range? - correct answer A
comfortable range is about -8C to +3C, but any given person has a different
comfort range
The amount of heat your body produces will be different if you're skiing
harder (warmer) or going for an easy cruise (colder)
What are the primary and secondary hazards of cold temperatures? -
correct answer Frostbite and hypothermia are primary hazards, and wind
chill can make a given temperature feel much colder
,A secondary effect is with cold temperatures that can lead to a formation of
a weak snow layer near the surface, which after being buried by
subsequent storms, can lead to avalanches
What clothing should you wear in cold temperatures? - correct answer A
temperature of about -10C or lower is colder than a typical day, so you'd
want to bring
Additional warm layers (like down, synthetic down, fleece, or wool);
Consider putting chemical warmers in your boots and gloves
What are some associated hazards with unreasonably warm
temperatures? - correct answer Heat stroke, dehydration
What is snow melt? - correct answer Any time the temperature gets to 0°C
or above, snowmelt starts to become a factor for ski conditions and
avalanche danger.
When there is a prolonged period of above freezing overnight temperatures
for the first time in spring, wet slab avalanches become more likely.
What are snow pits? - correct answer 1-2 m deep holes dug in the snow
to analyze potential layers of concern; ie unstable sections of the snow
pack, by doing layer identification, snow crystal type, and hardness tests
What is the hand hardness test? - correct answer The hardness of a layer
related to the density and cohesiveness of the layer. This test is done by
applying light pressure to each snow pack layer, with hardness levels from
softest to hardest being: fist, four fingers, one finger, pencil, and knife.
(done in opposite order)
The last thing you are easily able to push into the layer is the hardness
rating of the layer
,What is a weakly-bonded snow layer? - correct answer Weak snow within
a snowpack that has undergone faceting, and has less density and fewer
bonds between crystals → weaker and less cohesive
Another type of weak layer is surface hoar, which forms at the surface of a
snow pack and becomes a weak layer once it's buried in snow
What is a strongly-bonded snow layer? - correct answer Strong snow
within a snowpack, or a strong layer, that is most commonly made up of old
stellar dendrites (picture-perfect looking snowflakes with branches) that are
now rounded crystals (a.k.a. Rounds).
What is a crust layer? - correct answer A layer that forms when a rain-on-
snow event occurs and the water-saturated snow freezes.
The crusts themselves don't usually fail but they may lead to failure. For
example, crusts can block the flow of water vapour within the snowpack,
causing a weak layer of facets to form immediately above them in the
snowpack.
What determines if the whole snowpack is stable/unstable? - correct
answer The relative strength of the layers, with a stronger/more dense
layer on top of a weaker/less dense layer being seen as unstable
What is storm snow? - correct answer Snow that is currently falling or
newly fallen within the last 48 hours, with instabilities that are typically
short-lived, lasting only 12-48 hours as the new snow rapidly settles
What is temperature inversion? - correct answer When temperature
increases with height for some layer of air within the troposphere.
, What does it mean of layers are statically stable? - correct answer When
a layer of cool air lies beneath a layer of warmer air (an inversion is
present)
What is valley cloud and flog? - correct answer When inversion traps
moisture within a valley (since stable air resists vertical motion)
What is capping inversion? - correct answer Inversion can occur
elsewhere within the troposphere (dashed green lines) and acts like a cap
or lid. Generally, air rising from below does not get any higher than the
inversion layer.
How does inversion occur? - correct answer Subsidence from high
pressure, or radiative cooling of the ground
What is subsidence? - correct answer Large scale sinking motions
associated with high pressure systems. As the air descends (at the dry
adiabatic lapse rate) and becomes drier
What is radiative cooling of the ground? - correct answer On clear calm
nights, the earth's surface radiates heat into space and cools, which makes
the air in contact with the surface cool down as-well
In the winter, the snow amplifies the effect of inversion and makes it lose
heat more quickly
End result is wintertime inversions in mountain valleys can be sustained for
weeks on end under persistent high pressure.
What is climate? - correct answer The prevailing weather conditions of a
region over a long time (ie 30 years)
