ATMOS 1010 FINAL EXAM QUESTIONS & ANSWERS
How does Doug Chabot, who issued the Gallatin National Forest Avalanche Advisory,
characterize the avalanche danger on Jan. 1? - Answers - The avalanche danger was
"High" and there was an Avalanche Warning.
In the advisory, what does Doug say are the reasons for this level of avalanche danger?
Select all that are correct. - Answers - -New snow has been deposited on an extremely
weak snowpack
-Areas of unstable snow exist.
-Both natural and human triggered avalanches are likely.
What are the four components you need to have an avalanche? Select all four. -
Answers - -Steep slope
-Trigger
-Slab of snow
-Weak layer of snow
If you want to ski in the backcountry on "High" or "Considerable" danger day, what types
of areas are the safest to ski? - Answers - -A low angle slope with trees (and no steep
slopes above it)
Why was it difficult and dangerous for a helicopter to fly in to rescue the injured skier? -
Answers - The weather was terrible and the ceiling (cloud height) was low.
What is surface hoar and when does it form? Why does it help cause avalanches? -
Answers - Crystalline feathery frost that forms on cold clear nights. It provides a weak
layer.
What was the "human factor" that contributed to this avalanche accident? - Answers -
They kept going higher on the slope and into more dangerous terrain. The stoke of the
day.
What does the survivor say he would change if he were in the same situation again? -
Answers - If one member disagreed with the decision to ski a slope they would not ski it.
What should people do to stay safe in the backcountry? Select all that are correct. -
Answers - -Stay on low angle and treed slopes if conditions are dangerous.
-Read the avalanche forecast
-Recognize group dynamics and stoke.
-Constantly assess the safety of the current conditions and travel route.
-Get trained in avalanche science and safety.
What are the three basic ingredients for a winter storm? - Answers - Cold air, lift,
moisture
, What is supercooled water? - Answers - Liquid water that is below 0 degrees C
What is thundersnow? - Answers - Lightning that occurs during a snowstorm
For lake effect snow, what large scale weather pattern is needed? - Answers - A cold
airmass moves over a large body of warm water
What condition is present during a lake effect snowstorm? - Answers - The lake
temperature is warmer than the air temperature.
Imagine there are two lake in the western U.S.. Lake A has flat terrain downwind, but
lake B has mountains downwind. Which lake will likely have higher lake effect snow
amounts? - Answers - Lake B
On what slope angles do most avalanches occur? - Answers - 35-50 degrees
What should you do when traveling in avalanche terrain in order travel safely and
minimize your risk? - Answers - Only expose one person to hazard at a time and stay
alert to changing conditions.
What state has the greatest number of thunderstorm days per year? - Answers - Florida
Why is strong heating of the ground by the Sun associated with thunderstorms? -
Answers - It leads to greater instability
What type of thunderstorms are responsible for nearly all of the significant tornadoes
produced in the U.S. and for most of the hailstones larger than golf ball size? - Answers
- Supercell Thunderstorms
What causes the dissipating stage of a thunderstorm? - Answers - The spreading
downdraft cuts off air inflow into the updraft.
If a forecaster believes that tomorrow in Alabama numerous severe storms are possible
and they will be persistent and widespread, with a few being intense, what
Thunderstorm Risk category should they select for that region in their Convective
Outlook? - Answers - Enhanced
What is the rotating updraft of a Supercell Thunderstorm called - Answers -
Mesocyclone
What forecasting technique involves running several different computer models over the
same area, or running the same model several times with varying starting weather
conditions? - Answers - Ensemble Forecasting
Why doesn't the west coast of the U.S. experience very many thunderstorms? -
Answers - Cold ocean waters suppress convection
How does Doug Chabot, who issued the Gallatin National Forest Avalanche Advisory,
characterize the avalanche danger on Jan. 1? - Answers - The avalanche danger was
"High" and there was an Avalanche Warning.
In the advisory, what does Doug say are the reasons for this level of avalanche danger?
Select all that are correct. - Answers - -New snow has been deposited on an extremely
weak snowpack
-Areas of unstable snow exist.
-Both natural and human triggered avalanches are likely.
What are the four components you need to have an avalanche? Select all four. -
Answers - -Steep slope
-Trigger
-Slab of snow
-Weak layer of snow
If you want to ski in the backcountry on "High" or "Considerable" danger day, what types
of areas are the safest to ski? - Answers - -A low angle slope with trees (and no steep
slopes above it)
Why was it difficult and dangerous for a helicopter to fly in to rescue the injured skier? -
Answers - The weather was terrible and the ceiling (cloud height) was low.
What is surface hoar and when does it form? Why does it help cause avalanches? -
Answers - Crystalline feathery frost that forms on cold clear nights. It provides a weak
layer.
What was the "human factor" that contributed to this avalanche accident? - Answers -
They kept going higher on the slope and into more dangerous terrain. The stoke of the
day.
What does the survivor say he would change if he were in the same situation again? -
Answers - If one member disagreed with the decision to ski a slope they would not ski it.
What should people do to stay safe in the backcountry? Select all that are correct. -
Answers - -Stay on low angle and treed slopes if conditions are dangerous.
-Read the avalanche forecast
-Recognize group dynamics and stoke.
-Constantly assess the safety of the current conditions and travel route.
-Get trained in avalanche science and safety.
What are the three basic ingredients for a winter storm? - Answers - Cold air, lift,
moisture
, What is supercooled water? - Answers - Liquid water that is below 0 degrees C
What is thundersnow? - Answers - Lightning that occurs during a snowstorm
For lake effect snow, what large scale weather pattern is needed? - Answers - A cold
airmass moves over a large body of warm water
What condition is present during a lake effect snowstorm? - Answers - The lake
temperature is warmer than the air temperature.
Imagine there are two lake in the western U.S.. Lake A has flat terrain downwind, but
lake B has mountains downwind. Which lake will likely have higher lake effect snow
amounts? - Answers - Lake B
On what slope angles do most avalanches occur? - Answers - 35-50 degrees
What should you do when traveling in avalanche terrain in order travel safely and
minimize your risk? - Answers - Only expose one person to hazard at a time and stay
alert to changing conditions.
What state has the greatest number of thunderstorm days per year? - Answers - Florida
Why is strong heating of the ground by the Sun associated with thunderstorms? -
Answers - It leads to greater instability
What type of thunderstorms are responsible for nearly all of the significant tornadoes
produced in the U.S. and for most of the hailstones larger than golf ball size? - Answers
- Supercell Thunderstorms
What causes the dissipating stage of a thunderstorm? - Answers - The spreading
downdraft cuts off air inflow into the updraft.
If a forecaster believes that tomorrow in Alabama numerous severe storms are possible
and they will be persistent and widespread, with a few being intense, what
Thunderstorm Risk category should they select for that region in their Convective
Outlook? - Answers - Enhanced
What is the rotating updraft of a Supercell Thunderstorm called - Answers -
Mesocyclone
What forecasting technique involves running several different computer models over the
same area, or running the same model several times with varying starting weather
conditions? - Answers - Ensemble Forecasting
Why doesn't the west coast of the U.S. experience very many thunderstorms? -
Answers - Cold ocean waters suppress convection
