ATSC 113 FINAL: SNOW- SPORTS EXAM
QUESTIONS AND ANSWERS
What pressure- level map would generally be used for Grouse Mountain? - Answer-85.0
kPa= ~ 1500m
What kind of a system is used to make pressure- level maps? - Answer-NWP computer
model = "Numerical Weather Prediction" computer models
Pressure- level maps are usually animated loops made up of multiple maps for different
times. What 2 types of maps are seen? - Answer-First map = Analysis map
Subsequent maps = Forecast maps
T/F? No pressure- level map will ever show clouds. - Answer-False. Some pressure-
level maps may show TOTAL CLOUD COVER!
Why can't clouds be shown directly on weather maps? - Answer-Because satellites will
pick up clouds at different elevations (can't differentiate) => total cloud cover will be
shown rather than cloud coverage at a particular elevation
T/F? High- Pressure system is usually associated with high temperature but can have
low temperature as well. - Answer-True.
How does pressure change with increasing elevation? - Answer-Pressure decreases
with increasing elevation
What's the difference b/w low-level pressure maps and upper-level pressure maps? -
Answer-Low-level maps: low atmosphere= <50.0kPa
Upper-level maps: High atmospher= 50-25kPa(top of trophosphere)
How does the strength of the temperature gradient along a warm front compare to that
along a cold front? - Answer-Weaker temperature gradient b/c warm air moves more
slowly
Why does the unstable air mass behind a cold front turn stable in the evening? -
Answer-Heating source (sun) goes away--> ground isn't heated anymore --> not as
great of a temperature difference b/w ground air and upper atmospheric air temperature
T/F? The plotted wind speeds exclude effects of surface friction. - Answer-True.
Define: whiteout - Answer-when you see white everywhere (snow/cloud at your feet &
fog/cloud in the air around)
, Where are large scale light winds generally found? - Answer-Near centre of HPS where
there's a weak pressure gradient (isobars far apart) => not as strong movement of air
from HP region to LP region
Define: diurnal - Answer-A process that occurs on a daily basis
What is a frontal zone and how do you identify it? - Answer-Frontal Zone: a transition
zone along a front b/w 2 different air masses
Identify it using on a pressure- level map through...
1. Strong Horizontal Temperature Gradient(on surface + pressure-level maps)
2. Pressure Trough (Pressure-level map)
Secondary Indicators:
1. Wind shift: change in wind direction across front
2. Higher relative humidity
Define: tree bombs - Answer-large clumps of snow thaat fall out of trees b/c of swaying
due to windy conditions
Give one example of a time when temperature adjustments aren't required during
vertical temperature interpolation due to heating/cooling - Answer-During Frontal
Passage
What are considered "unusually cold temperatures" and what are its risks? - Answer-(-
10 degrees celsius or lower)
-frostbite
-hypothermia
-avalanche risk
What are considered "unusually warm temperatures" and what are its risks? - Answer-
(5 degrees celsius or higher)
-heat stroke
-hyperthermia
Define: meteograms - Answer-x-axis= time
y-axis= weather variable
Why is the Freezing Level NOT EQUAL TO the Rain-Snow Line? - Answer-Snow
crystals fall some distance (200 to 300m) before melting => Rain-Snow line is 200-
300m below freezing level.
What is the optimum snow density for powder skiing? - Answer-8%
Define: storm snow - Answer-Snow that is falling/has fallen in the last 48 hours
Define climate - Answer-Is the average weather at a given place over a long period of
time.
QUESTIONS AND ANSWERS
What pressure- level map would generally be used for Grouse Mountain? - Answer-85.0
kPa= ~ 1500m
What kind of a system is used to make pressure- level maps? - Answer-NWP computer
model = "Numerical Weather Prediction" computer models
Pressure- level maps are usually animated loops made up of multiple maps for different
times. What 2 types of maps are seen? - Answer-First map = Analysis map
Subsequent maps = Forecast maps
T/F? No pressure- level map will ever show clouds. - Answer-False. Some pressure-
level maps may show TOTAL CLOUD COVER!
Why can't clouds be shown directly on weather maps? - Answer-Because satellites will
pick up clouds at different elevations (can't differentiate) => total cloud cover will be
shown rather than cloud coverage at a particular elevation
T/F? High- Pressure system is usually associated with high temperature but can have
low temperature as well. - Answer-True.
How does pressure change with increasing elevation? - Answer-Pressure decreases
with increasing elevation
What's the difference b/w low-level pressure maps and upper-level pressure maps? -
Answer-Low-level maps: low atmosphere= <50.0kPa
Upper-level maps: High atmospher= 50-25kPa(top of trophosphere)
How does the strength of the temperature gradient along a warm front compare to that
along a cold front? - Answer-Weaker temperature gradient b/c warm air moves more
slowly
Why does the unstable air mass behind a cold front turn stable in the evening? -
Answer-Heating source (sun) goes away--> ground isn't heated anymore --> not as
great of a temperature difference b/w ground air and upper atmospheric air temperature
T/F? The plotted wind speeds exclude effects of surface friction. - Answer-True.
Define: whiteout - Answer-when you see white everywhere (snow/cloud at your feet &
fog/cloud in the air around)
, Where are large scale light winds generally found? - Answer-Near centre of HPS where
there's a weak pressure gradient (isobars far apart) => not as strong movement of air
from HP region to LP region
Define: diurnal - Answer-A process that occurs on a daily basis
What is a frontal zone and how do you identify it? - Answer-Frontal Zone: a transition
zone along a front b/w 2 different air masses
Identify it using on a pressure- level map through...
1. Strong Horizontal Temperature Gradient(on surface + pressure-level maps)
2. Pressure Trough (Pressure-level map)
Secondary Indicators:
1. Wind shift: change in wind direction across front
2. Higher relative humidity
Define: tree bombs - Answer-large clumps of snow thaat fall out of trees b/c of swaying
due to windy conditions
Give one example of a time when temperature adjustments aren't required during
vertical temperature interpolation due to heating/cooling - Answer-During Frontal
Passage
What are considered "unusually cold temperatures" and what are its risks? - Answer-(-
10 degrees celsius or lower)
-frostbite
-hypothermia
-avalanche risk
What are considered "unusually warm temperatures" and what are its risks? - Answer-
(5 degrees celsius or higher)
-heat stroke
-hyperthermia
Define: meteograms - Answer-x-axis= time
y-axis= weather variable
Why is the Freezing Level NOT EQUAL TO the Rain-Snow Line? - Answer-Snow
crystals fall some distance (200 to 300m) before melting => Rain-Snow line is 200-
300m below freezing level.
What is the optimum snow density for powder skiing? - Answer-8%
Define: storm snow - Answer-Snow that is falling/has fallen in the last 48 hours
Define climate - Answer-Is the average weather at a given place over a long period of
time.
