Air Masses and Changing Weather

These flashcards cover key concepts related to air masses, weather fronts, and weather forecasting methods.

What is an air mass?

A huge volume of air that has a uniform temperature and humidity at a given altitude.

How are air masses classified?

Air masses are classified based on where they form and their characteristics using letters m, c, P, and T.

What does the letter 'm' in air mass classification stand for?

'm' stands for 'maritime', indicating the air mass was formed over water and is moist.

What does the letter 'c' in air mass classification stand for?

'c' stands for 'continental', indicating the air mass was formed over land and is dry.

What does the letter 'P' in air mass classification stand for?

'P' stands for 'polar', indicating that the air mass is cold.

What does the letter 'T' in air mass classification stand for?

'T' stands for 'tropical', indicating that the air mass is warm.

What are the four common types of air masses that affect the United States?

They are mP (maritime Polar), mT (maritime Tropical), cP (continental Polar), and cT (continental Tropical).

What is the main factor that determines the characteristics of an air mass?

The properties of the land or water over which the air mass forms.

What is a weather front?

A boundary that forms between two air masses where they collide.

What are the four types of weather fronts?

They are cold fronts, warm fronts, stationary fronts, and occluded fronts.

What is a cold front?

A weather front in which a cold air mass advances to replace a warm air mass.

What type of weather do cold fronts typically bring?

Cold fronts often bring stormy weather.

What is a warm front?

A weather front in which a warm air mass slides over a cold air mass.

How does weather usually change with a warm front?

Warm fronts bring steadier and gentler precipitation compared to cold fronts.

What is a stationary front?

A boundary between a cold air mass and a warm air mass that are not moving past each other.

What happens at a stationary front?

The weather is similar to that at a warm front and may last for many days.

What is an occluded front?

A boundary between one warm air mass and two cold air masses.

What weather is associated with low pressure systems?

Low pressure systems are usually associated with stormy weather.

What weather is associated with high pressure systems?

High pressure systems are typically associated with fair or clear weather.

What measurement can indicate a low pressure system is approaching?

Decreasing air pressure may indicate a low pressure system is approaching.

What instruments measure atmospheric pressure?

Barometers measure atmospheric pressure.

What do isobars represent on a weather map?

Isobars are lines that connect places with the same air pressure.

What does a high pressure system signify in terms of weather?

It signifies fair weather is likely.

What is the role of weather stations?

Weather stations gather data necessary for weather forecasting.

What tools do scientists use at weather stations?

Thermometers, barometers, anemometers, rain gauges, and hygrometers.

What data do weather balloons collect?

They collect data on temperature, air pressure, wind speed, and humidity at various altitudes.

What role do satellites play in weather forecasting?

Satellites collect data about temperature, humidity, and cloud cover.

What is Doppler radar used for?

Doppler radar is used to gather data about precipitation and storm movement.

How do scientists predict weather conditions?

They analyze data collected from weather stations, balloons, radar, and satellites.

What is the probability of precipitation?

The likelihood of a certain type of weather occurring, expressed as a percentage.

What does a 50% chance of thunderstorms indicate?

There is an equal likelihood of thunderstorms or calm weather.

What does a weather map show?

It shows weather patterns, fronts, low and high pressure systems, and isobars.

What does a cold front symbol look like on a weather map?

A blue line with triangles pointing in the direction the front is moving.

What does a warm front symbol look like on a weather map?

A red line with semicircles pointing in the direction the front is moving.

What does high pressure symbol look like on a weather map?

A large blue 'H' representing a high pressure system.

What are the characteristics of a stationary front symbol on a map?

Alternating red semicircles and blue triangles pointing in opposite directions.

Why do meteorologists use models in weather forecasting?

Models help predict the probability of weather conditions and how weather patterns will change.

What does a high percentage in the probability of precipitation suggest?

It suggests that precipitation is more likely to occur.

How does rising air in a low pressure system influence weather?

Rising air leads to cloud formation and potentially precipitation.

How does sinking air in a high pressure system affect the weather?

Sinking air warms and can hold more water, leading to clearer skies.