Air Masses and Storms Flashcards
What air mass forms over high latitude oceans?
Maritime polar
What air mass forms over low latitude oceans?
Maritime tropical
What air mass forms over high latitude land?
Continental polar
What air mass forms over low latitude land?
Continental tropical
What air mass contains warm, moist air?
Maritime tropical
What air mass contains hot, dry air?
Continental tropical
What air mass contains cold, dry air?
Continental polar
What air mass contains cool, moist air?
Maritime polar
Air masses are characterized by what two characteristics?
moisture and temperature
What is an air mass?
A large parcel of air that takes on the characteristics of the surface over which it forms.
Which air mass likely forms over the northern Pacific ocean?
Maritime polar
Which air mass likely forms over the Gulf of Mexico?
Maritime tropical
Which air mass likely forms over Canada?
Continental polar
What forms when two air masses collide?
A front
Which type of front forms when a cold air mass moves into and under a warm air mass?
A cold front
Which type of front forms when a warm air mass moves into and over a cold air mass?
A warm front
Which type of front forms when a cold front overtakes a warm front?
An occluded front
Which type of front forms when one air mass does not have enough energy to push another air mass out of an area?
A stationary front
What is a polar front?
A condition when cold polar air meets warm tropical air.
What can form at a low pressure area?
A frontal cyclone. (Also called a mid-latitude cyclone)
What can form at a high pressure area?
An anticyclone
Frontal cyclones usually produce what type of weather?
Clouds and storms
Anticyclones usually produce what type of weather?
Clear and dry conditions
What type of storms consists of winds, precipitation and lightning?
Thunderstorm
What is the electrical discharge between a cloud and the ground, within a cloud, or between two clouds called?
Lightning
What is the sound produced when an electrical discharge moves air very rapidly called?
Thunder
In what type of cloud are thunderstorms produced?
Cumulonimbus
How does hail form?
Updrafts in a cumulonimbus cloud force water droplets to a colder temperature region, where they freeze, then fall. This process continues until the ice pellet is too heavy to remain in the cloud.
What should a person do in a thunderstorm?
Seek shelter immediately. If outside, avoid tall objects and low-lying areas that could flood. Remain in a car if possible.
What is a flash flood?
Fast-moving water in low-lying areas that forms from heavy precipitation.
What is a small downdraft that then moves horizontally across Earth’s surface in all directions called?
A microburst
Which stage of a thunderstorm forms tall clouds containing updrafts?
Cumulus stage
Which stage of a thunderstorm produces strong updrafts and downdrafts, heavy precipitation, and lightning?
Mature stage
When the thunderstorm no longer has a source of warm, moist air to sustain it, the storm enters which stage?
Dissipating stage
What forms when rapidly rotating winds extend downward to touch the ground?
A tornado
What is the shape of a tornado?
Funnel-shaped
Tornadoes are associated with what other type of storm?
A supercell thunderstorm
Where in the United States is Tornado Alley located?
In the central United States
How long do most tornadoes last?
Only a few minutes, but they could last for hours.
What is a rapidly rotating cyclonic storm system that forms over tropical waters?
A Hurricane
What is the general shape of a hurricane?
Spiral shaped
What are the stages of a hurricane?
A hurricane starts as a tropical depression, then grows into a tropical storm. When wind speeds are greater than 74 mph, they become hurricanes.
Where are the calmest winds during a hurricane?
Inside the eye
Where are the most damaging winds during a hurricane?
Along the eye wall
What are some possible hazards associated with hurricanes along a shoreline?
Heavy winds, heavy precipitation, storm surges, and erosion of the shore.
What are some possible hazards associated with hurricanes inland from a shore?
Heavy winds, including possible tornadoes, and precipitation.
What is the size of a hurricane?
Large storm covering 62 to 1000 miles, with an average of 300 miles wide.
How long do hurricanes last?
They can last several days.
What is ENSO (El Nino Southern Oscillation)
Weather conditions that form when ocean water off the coast of Peru remains unseasonably warm or cold.
What causes an El Nino?
The weakening of the Trade Winds keeps warm water along the coast of Peru and prevents upwelling of cold water.
How do weather conditions change during an El Nino season in the US?
Precipitation increases in the southern part of the country. Areas to the north will have warmer, milder winters.
What is a Monsoon?
Seasonal changes in atmospheric circulation and precipitation.
What causes a Monsoon?
Seasonal differences in heating of the ocean and land
During the wet season of the Monsoon, how does atmospheric circulation move?
Moist air flows horizontally from the oceans onto the land to take the place of rising air on land.
During the dry season, how does atmospheric circulation move?
Air sinks over the land, then moves horizontally from the land to the ocean.
