ATSC 113 FINAL EXAM STUDY GUIDE QUESTIONS WITH
ANSWERS 2025/2026
Cold front - Southerly in NA, warm humid air advects from S. Strong winds, gusty, P rel.
Min.
Associated w/ Cumuliform clouds.
T decreases w/ time behind the front.
Winds are stronger near fronts
Cold fronts bring a narrow band of precipitaiton
Warm front - Easterly ahead southerly behind, Wind ahead is cool & humid.
Associated w/ Stratiform clouds ahead. Alongside, extensive low clouds & fog.
Weak T gradient
Gradual T increase may change the precipitation
Reduced vis & thick clouds/fog
TS - Convective clouds driven by buoyancy of warm rising air. Most common in spring &
summer. Stay at least 20 nm away.
TS cells - *Each is an individual TS.
1) Cumulus: updraft, no rain, no anvil, not vis on radar.
2) mature: up & down drafts, rain, anvil, most violent, rain vis on radar.
3) Dissipating: Down, raining itself out, leaving ice crystals in the mid & top, not very vis
on radar.
*4) Residue: ice crystals in the anvil, long time to evap, blocks VFR.
Single-cell & Multi-cell storm TS - basic storms
Single-cell: short-lived (15-30min), not violent.
Multi-cell: 2 or more, each can be at dif. stages.
Orographic TS - Formed when wind blows warm, humid air towards hills & Mt, if cloud
forms -> could develop into TS. If stationary, flashfloods. Basic Storm (along w/ single &
multi-cell).
Bow-echo TS - Line of TS bent into an arc by fast wind fromt behind (rear inflow jet).
Mesoscale Convective Complex - Line/region of strong TS cells w/ heavy rain followed
by moderate & light rain extending over a broad region. (Mesoscale convective system
TS including squall-line, bow-echo, mesoscale convective vortex).
Mesoscale convective vortex - After MCC dissipates, MCV is the remaining non-stormy
clouds at mid-alt w/ a slow cc-rotation. May lead to MCC from heat next day.
Super cell TS - most dangerous/ longest-lived, updraft often appear as slow rotating
cloud column => mesocyclone (supercell). Includes (low- & high-precipitation and
classic supercells.
,Low- & high-precipitation supercell TS - Low: not much rain, may produce large hail &
downburst winds.
High: rain much more extensive, rain wrapped completely around the centre of rotation
of mesocyclone.
Classic supercell TS - Though only a small % supercells spawn tornadoes, they are the
strongest.
These can have a hook echo shape as rain wraps L pressure region of the storm called
meso-low.
Often, the whole TS rotates slowly as mesocyclone.
Aviation weather services - Aviation weather website (AWWS) (Canada), Aviation
weather centre (AWC) (USA).
METAR (Aviation Routine Weather Report): current weather. SPECI reported when
significant changes in weather takes place.
TAF (Terminal Aerodrome forecasts): Future weather.
Turbulence - Random fluctuations of wind, consists of eddies.
Convective - due to buoyancy
Wind-shear - due to dif. wind speeds/directions at dif. alt.
Obstacle - wind circumnavigating an object
Recommended maneuvering speed - is slow enough to stall when violent controls input
instead of falling out.
Clear Air Turbulence & Sucker hole - Severe turbulence in clear air.
A gap of clear air btw TS w/ severe turbulence is "sucker hole".
Downbursts - Rapidly descending air, found below clouds that have precipitation or
virga (evap before hitting the ground). Smaller diameter & shorter duration are called
microbursts.
Gust fronts - When cold downburst hits the ground -> radial straight-line winds. The
leading edge is gust front.
May lead to low-level wind shear, aircrafts may climb higher/lower than glidescope
(descending path). Pilots may fly fast, go around, or do a holding pattern.
If enough moisture -> arc cloud.
In dry conditions -> haboob (wall of dust), touches the ground whereas arc cloud
doesn't.
Hailstone - ice balls >0.5cm in diameter that falls from TS. The dmg path is hail swath
(giant hail 5cm>x>1.9cm, graupel <0.5cm)
Terminal fall V increases with size.
Large hailstones form if updraft speed > Terminal fall V (i.e. supercell).
Hail falls closest to the main updraft -> hail shaft.
, Tornadoes - Violently rotating columns of air btw TS, clouds, and ground. Tornado
funnel often vis from cloud droplets or dirt.
Enhanced Fujita scale relates tornado dmg intensity to rotational speed.
What is the hazard associated with rain? - Reduced visibility. However, ingestion of
heavy rain into turbine engine can cause it to stop.
Clear ice vs Rime ice - Clear ice: slow freezing of large raindrops -> relatively clear (or
dark), hard, difficult to remove.
Rime ice: smaller cloud droplets freeze instantaneously, traps air pockets, brittle.
*supercooled droplets can be liq 0C to -40C.
Deicing vs anti-icing - Deicing removes ice (i.e. pneumatic boots, antifreeze/chemical,
carburator heat control).
Anti-icing prevents ice formation (i.e. jet exhaust duct, electric heater, carburator heat
control).
PIREPS of ice - pilot reports on icing intensity.
*Trace - perceptible
Light - problematic if prolonged
Moderate - short encounters may be dangerous
Severe - deicing/anti-icing fail
Lightning - Long, thin spark created in TS. Can be btw cloud & ground, 2 clouds, within
a cloud, cloud to air.
Forms from collision of small ice crystals & hailstones (graupels)
Small ice crystals (+) carried to the top of TS by updraft to anvil while larger graupel (-)
towards bot as they fall.
When the voltage dif. is big enough, insulative air ->ionized, conductive. Greater build
up of voltage = longer lightning
P-static - Sparks on the outside of aircraft from contact with uncharged particles and (-)
builds up on the surface.
(St. Elmo Fire = corona discharge as filaments of light writhing on the outside).
Cumuliform clouds - Warm humid air rising through cooler surrounding air. Strong
updrafts.
S - Cumulus humilis
M - Cumulus mediocris
L - Cumulus congestus
XL -Cumulonimbus/TS
Happens when air near ground is colder than the ground (clear day w/ sunshine).
Happens behind cold front. *btw updrafts are weaker downdrafts of clear air. downdraft
causing wind gusts leading to darker patches of water = "cat's paws"
ANSWERS 2025/2026
Cold front - Southerly in NA, warm humid air advects from S. Strong winds, gusty, P rel.
Min.
Associated w/ Cumuliform clouds.
T decreases w/ time behind the front.
Winds are stronger near fronts
Cold fronts bring a narrow band of precipitaiton
Warm front - Easterly ahead southerly behind, Wind ahead is cool & humid.
Associated w/ Stratiform clouds ahead. Alongside, extensive low clouds & fog.
Weak T gradient
Gradual T increase may change the precipitation
Reduced vis & thick clouds/fog
TS - Convective clouds driven by buoyancy of warm rising air. Most common in spring &
summer. Stay at least 20 nm away.
TS cells - *Each is an individual TS.
1) Cumulus: updraft, no rain, no anvil, not vis on radar.
2) mature: up & down drafts, rain, anvil, most violent, rain vis on radar.
3) Dissipating: Down, raining itself out, leaving ice crystals in the mid & top, not very vis
on radar.
*4) Residue: ice crystals in the anvil, long time to evap, blocks VFR.
Single-cell & Multi-cell storm TS - basic storms
Single-cell: short-lived (15-30min), not violent.
Multi-cell: 2 or more, each can be at dif. stages.
Orographic TS - Formed when wind blows warm, humid air towards hills & Mt, if cloud
forms -> could develop into TS. If stationary, flashfloods. Basic Storm (along w/ single &
multi-cell).
Bow-echo TS - Line of TS bent into an arc by fast wind fromt behind (rear inflow jet).
Mesoscale Convective Complex - Line/region of strong TS cells w/ heavy rain followed
by moderate & light rain extending over a broad region. (Mesoscale convective system
TS including squall-line, bow-echo, mesoscale convective vortex).
Mesoscale convective vortex - After MCC dissipates, MCV is the remaining non-stormy
clouds at mid-alt w/ a slow cc-rotation. May lead to MCC from heat next day.
Super cell TS - most dangerous/ longest-lived, updraft often appear as slow rotating
cloud column => mesocyclone (supercell). Includes (low- & high-precipitation and
classic supercells.
,Low- & high-precipitation supercell TS - Low: not much rain, may produce large hail &
downburst winds.
High: rain much more extensive, rain wrapped completely around the centre of rotation
of mesocyclone.
Classic supercell TS - Though only a small % supercells spawn tornadoes, they are the
strongest.
These can have a hook echo shape as rain wraps L pressure region of the storm called
meso-low.
Often, the whole TS rotates slowly as mesocyclone.
Aviation weather services - Aviation weather website (AWWS) (Canada), Aviation
weather centre (AWC) (USA).
METAR (Aviation Routine Weather Report): current weather. SPECI reported when
significant changes in weather takes place.
TAF (Terminal Aerodrome forecasts): Future weather.
Turbulence - Random fluctuations of wind, consists of eddies.
Convective - due to buoyancy
Wind-shear - due to dif. wind speeds/directions at dif. alt.
Obstacle - wind circumnavigating an object
Recommended maneuvering speed - is slow enough to stall when violent controls input
instead of falling out.
Clear Air Turbulence & Sucker hole - Severe turbulence in clear air.
A gap of clear air btw TS w/ severe turbulence is "sucker hole".
Downbursts - Rapidly descending air, found below clouds that have precipitation or
virga (evap before hitting the ground). Smaller diameter & shorter duration are called
microbursts.
Gust fronts - When cold downburst hits the ground -> radial straight-line winds. The
leading edge is gust front.
May lead to low-level wind shear, aircrafts may climb higher/lower than glidescope
(descending path). Pilots may fly fast, go around, or do a holding pattern.
If enough moisture -> arc cloud.
In dry conditions -> haboob (wall of dust), touches the ground whereas arc cloud
doesn't.
Hailstone - ice balls >0.5cm in diameter that falls from TS. The dmg path is hail swath
(giant hail 5cm>x>1.9cm, graupel <0.5cm)
Terminal fall V increases with size.
Large hailstones form if updraft speed > Terminal fall V (i.e. supercell).
Hail falls closest to the main updraft -> hail shaft.
, Tornadoes - Violently rotating columns of air btw TS, clouds, and ground. Tornado
funnel often vis from cloud droplets or dirt.
Enhanced Fujita scale relates tornado dmg intensity to rotational speed.
What is the hazard associated with rain? - Reduced visibility. However, ingestion of
heavy rain into turbine engine can cause it to stop.
Clear ice vs Rime ice - Clear ice: slow freezing of large raindrops -> relatively clear (or
dark), hard, difficult to remove.
Rime ice: smaller cloud droplets freeze instantaneously, traps air pockets, brittle.
*supercooled droplets can be liq 0C to -40C.
Deicing vs anti-icing - Deicing removes ice (i.e. pneumatic boots, antifreeze/chemical,
carburator heat control).
Anti-icing prevents ice formation (i.e. jet exhaust duct, electric heater, carburator heat
control).
PIREPS of ice - pilot reports on icing intensity.
*Trace - perceptible
Light - problematic if prolonged
Moderate - short encounters may be dangerous
Severe - deicing/anti-icing fail
Lightning - Long, thin spark created in TS. Can be btw cloud & ground, 2 clouds, within
a cloud, cloud to air.
Forms from collision of small ice crystals & hailstones (graupels)
Small ice crystals (+) carried to the top of TS by updraft to anvil while larger graupel (-)
towards bot as they fall.
When the voltage dif. is big enough, insulative air ->ionized, conductive. Greater build
up of voltage = longer lightning
P-static - Sparks on the outside of aircraft from contact with uncharged particles and (-)
builds up on the surface.
(St. Elmo Fire = corona discharge as filaments of light writhing on the outside).
Cumuliform clouds - Warm humid air rising through cooler surrounding air. Strong
updrafts.
S - Cumulus humilis
M - Cumulus mediocris
L - Cumulus congestus
XL -Cumulonimbus/TS
Happens when air near ground is colder than the ground (clear day w/ sunshine).
Happens behind cold front. *btw updrafts are weaker downdrafts of clear air. downdraft
causing wind gusts leading to darker patches of water = "cat's paws"
