Sem#2 Chap 3 Flashcards
Hazardous winter weather list:
- Cold, snow, ice, and wind
- Traffic accidents
- Commerce disruptions
- Potential casualties
Winter weather advisory
There is an anticipation that freezing rain and/or snow will accumulate sufficiently to cause inconvenience and hazards
Winter storm watch
There is a possibility of hazardous winter weather in the next 48 hours; the weather can
be a combination of snow, sleet, ice accumulation, and wind, significant enough to cause
damage and/or life-threatening situations
Winter storm warning
The conditions stated for a winter storm watch are occurring or are imminent.
Blizzard warning
Conditions expected to occur during the next 12–18 hours include snow and/or blowing
snow, reducing visibility to ≤0.40 km (≤0.25 mi) for 3 hours or longer, and sustained winds of ≥56 km/h (≥35 mph).
Ice storm warning
A hazardous amount of ice (generally meaning ≥0.64 cm, or ≥0.25 in) will accumulate on
roads, trees, power lines, and other structures.
Freeze watch
Temperatures are expected to fall below 0°C (32°F) within the next 1–1.5 days during the
growing season, damaging plants and crops.
Freeze warning
Temperatures will fall below 0°C (32°F) during the growing season, damaging plants and
crops.
Frost advisory
A potential exists that temperatures may fall below 0°C (32°F) during the growing season, damaging plants and crops.
Wind chill advisory
The combination of cool temperatures and wind could lead to frostbite for exposed skin or to hypothermia.
Wind chill warning
The combination of cool temperatures and wind will quickly lead to frostbite for exposed skin or to hypothermia.
Reasons for the Atlanta Disaster
Lack of widespread public transportation
* Private cars clogged roads.
Slow public response
* Students and employees released after storm began.
Drivers lacked experience driving in snow and ice.
* Accidents halt traffic flow.
Poor emergency response:
* Many municipalities sprawl across the region.
* No comprehensive, regional emergency coordination.
Frostbite occurs when ….
when body tissue freezes.
Body must maintain a core temperature of _____C.
37°
Hypothermia
- When core temperature drops below safe range
- Mild, then severe, shivering
- Death results if core stays below 33.3°C
Wind chill temperature
- Represents heat loss when dry skin is exposed to wind
- Depicts exposure time that leads to frostbite
Your body creates a thin layer of warm air next to your skin.
Wind strips away warm layer, causing you to lose heat.
Wet skin cools faster than dry skin due to evaporation.
Class Question #1
Identify the common link between Atlanta’s “Snowpocalypse” of 2014,
Napoleon’s defeat in 1812, and Germany’s defeat in 1942.
a) Traffic accidents prevented food and clothing supplies from
reaching people in their vehicles.
b) People and organizations were unprepared for hazardous winter
weather conditions.
c) Inadequate regional coordination created flight delays and
cancellations.
d) Officials ignored winter advisories from the National Weather
Service (NWS).
d) Officials ignored winter advisories from the National Weather
Service (NWS)
Polar front:
- The boundary between cold polar air and warmer air
- Stretches around globe, normally at high latitudes
Polar vortex:
- Counterclockwise flow of polar air
- Circulates around the North Pole
Polar front jet stream:
- Traces out the southern edge of the polar vortex
Sometimes polar front extends ______
far south.
Polar front normally exists between _______ latitude
40°–60°
Cold waves
- Defined relative to normal, expected conditions
- Require society to take precautions against cold
Snowfall intensity depends on _________
visibility
3 Types of Visibility
- Light: visibility >1 km
- Moderate: visibility 1–0.5 km
- Heavy: visibility < 0.5 km
Snowpack
is a composite layer of multiple snowfalls.
Blizzards are defined based on two criteria:
- Winds >56 km/h
- Visibility <0.40 km for 3 hours
Whiteout conditions:
- Visibility reduced to 0 km.
- People cannot distinguish between the ground and sky.
Ground blizzards
- Occur in clear weather
- Wind blows dry snow ~15 meters high.
Hazardous Conditions from Ice Storms
Surfaces become coated in ice from freezing rain.
A warm, moist air mass flows above a cold air mass.
* Precipitation begins as snow or rain.
0°C isotherm: the boundary separating warmer and colder air
Ice storms occur when precipitation falls through the 0°C isotherm.
Precipitation type depends on location relative to 0°C isotherm.
Different Types of percipetation
Rain: Air is above-freezing
Freezing rain: Supercooled rain freezes on contact with surfaces. (0 degrees)
Sleet: Warm air wedge is not very
deep, nor very warm.
- Snow falling through warm
air wedge partially melts.
Snow: Air is below freezing.
Class Question #2
What happened to precipitation during the Great Ice Storm of 1998?
a) Rain fell through the 0°C isotherm and was supercooled.
b) Rain fell from high elevations, through a warm air mass, all the way
to the ground.
c) Snow fell from high elevations, through a cold air mass, all the way
to the ground.
d) Snow falling through the 0°C isotherm partially melted.
a) Rain fell through the 0°C isotherm and was supercooled.
(correct answer)
Most winter storms occur within _________ (what type of storm)
mid-latitude cyclones
Mid-latitude cyclones during winter differ from summer by characteristics of:
- More frequent, intense, and bigger than during summer
- Large temperature contrast between poles and tropics
Mid-latitude cyclones resemble a comma
Nor’easters:
- Storms with strong winds blowing from the northeast
- Create severe storms along east coast of N. America
Oceanic Cyclones
Wintertime mid-latitude cyclones over oceans
Common in northeastern Pacific and north Atlantic
Stronger than continental mid-latitude cyclones:
- Warm water provides energy for the storm.
- Wind has no barriers to block or slow its flow.
Ships and offshore drilling platforms are at risk.
Create intense storms when making landfall
Class Question #3
Why are nor’easter storms called nor’easters?
a) because the northeastern quadrant of these storms is the most
intense
b) because they only impact the southeastern states of the U.S.
c) because these storms generate waves that blow from the southwest
to the northeast
d) because strong winds blow from the northeast
d) because strong winds blow from the northeast (correct
answer)
Cold Air Damming
When low-altitude cold air is trapped by a mountain range
Seen on the eastern side of Appalachian Mountains
Often creates ice storms:
* Warm, moist ocean air moves inland.
* Warm air rises above cold air.
* Precipitation falls through the 0°C isotherm.
May cause freezing rain in South Carolina and Georgia
Lake-Effect Snowstorms
The Great Lakes retain heat and moisture late into the year.
Heat and moisture rise as cold, Canadian air passes over lakes.
Clouds form and precipitate snow on downwind shores.
Common in late November and early January
May develop after a mid-latitude cyclone’s cold front passes a lake
Snow may fall at 2.5 cm/hr for several days.
Impact zone is ~50–80 km from shore.
Orographic uplift creates ______
clouds on windward flanks.
Definition: Terrain forces winds/air to flow upwards
Mountain Snowstorms
Orographic uplift creates clouds on windward flanks.
Clouds precipitate snow during winter months.
Create the heaviest snowstorms and snowpacks in the world
Common in western, Rocky Mountain states
Often force closure of east-west interstate highways
Triggered avalanches ensure safe roads
Melting snowpack provides power generation and irrigation.
Class Question #4
What type of hazardous winter weather is South Carolina most likely to
experience?
a) blizzards
b) lake-effect snowstorms
c) ice storms
d) mountain snowstorms
c) ice storms (correct answer)
Bora
A strong, cold windstorm
Hazardous winter weather can be fatal. (list stuff)
- Traffic accidents
- Heart attacks from shoveling
- Falls on slippery surfaces
- Infection from frostbite
- Hypothermia
- Carbon monoxide poisoning
Safe traveling on roads: (list of what to prepair)
- Cell phone and charger
- Clothing, blanket, food, water
- Remain in car if stranded
- Ensure tailpipe is clear if
running engine while stuck
If aircraft cannot de-ice:
- Must remain grounded during winter months
- Fly only in warmer climates where icing is less likely
_______ and ______ are used to
de-ice aircraft prior to flight.
Glycol and water
Aircraft become unstable
from ______ and may crash.
ice
Property Damage and Hazardous Winter Weather
Homes may experience burst water pipes and flooded rooms.
Water mains may burst, cutting off water to neighborhoods.
Electric grid may fail, cutting off power to millions of people.
Highways, railroads, and airports may close.
Ice jams may halt river transportation.
Transportation disruptions cause supply shortages.
Hoarding goods exacerbates supply shortages.
Winter weather commonly causes _______ .
Economic damage
Preparing for Winter-Weather Disasters: Vulnerability is increasing:
- Climate change
- Decaying infrastructure
Preparing for Winter-Weather Disasters: Community investments:
- Plows, salt and sand trucks
- Backup generators
Preparing for Winter-Weather Disasters: Electrical grid protection:
- Bury power lines
- Prune trees
- Reinforce cell towers
- Invest in weather resistant equipment
- Ensure reserve electrical generating capacity
Class Question #5
Identify how China’s 2008 winter disaster was similar to Texas’s 2021
winter disaster.
a) The electric grid failed.
b) Homes were damaged from burst water pipes.
c) Water supplies were disrupted.
d) All of the listed winter disasters occurred in China and Texas.
d) All of the listed winter disasters occurred in China and Texas.
(correct answer)
