The percentage of water vapor that is actually in the air compared to the maximum amount of water vapor the air can hold at a particular temperature.
What is relative humidity?
100
Also known as a thunderhead, this is where a thunderstorm forms.
What is a cumulonimbus cloud?
100
Air masses with warm temperatures and low air pressure.
What are tropical air masses?
100
Air that is more dense, and therefore sinks.
What is cold air?
100
Major wind belts that generally push air masses from West to East.
What are prevailing westerlies?
200
The temperature at which condensation begins.
What is dew point?
200
An announcement that a tornado has been seen in the sky or on weather radar.
What is a tornado warning?
200
Cool, dry air masses formed over central and Northern Canada.
What is continental polar?
200
These are generally the fastest moving air masses and they tend to sink. It moves into a warmer air mass and slides underneath due to the densities.
What is a cold front?
200
When the temperature that water vapor condenses is below zero.
What is frost?
300
An instrument that measures relative humidity.
What is a psychrometer?
300
A tropical cyclone with winds of 119 kilometers per hour or higher.
What is a hurricane?
300
Warm, humid air masses that form over tropical oceans such as the Gulf of Mexico and Atantic and Pacific Oceans.
What is maritime tropical?
300
Fast moving warm air mass overtakes a slow moving cold air mass. Accompanied by clouds and precipitation.
What is warm front.
300
A hurricane or tornado.
What is a cyclone?
400
When the wet-bulb depression is large.
What is low relative humidity?
400
When a cold air mass from Canada moves southeast and picks up water vapor and heat from one of the Great Lakes. The air then cools over land, water vapor condenses and falls as snow.
What is Lake-Effect Snow?
400
Hot, dry air masses formed mostly in the summer over dry areas of the Southwest and northern Mexico.
What is continental tropical?
400
When a warm air mass and a cold air mass meet but neither can move. It can bring days of bad weather.
What is a stationary front?
400
When air moves in a clockwise direction around a swirling center of high pressure in the Northern Hemisphere. Usually associated with dry, clear weather.
What is an anticyclone?
500
The difference between the dry-bulb temperature and the wet-bulb temperature
What is wet-bulb depression?
500
a rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth's surface.
What is a tornado?
500
Cool, humid air masses form over North Pacific and North Atlantic oceans.
What is maritime polar?
500
When a warm air mass gets caught in between two cooler air masses. The cooler air forces the warmer air up, and the warm air is cut off from the ground.
What are occluded fronts?
500
Bands of high-speed winds about 10 kilometer above Earth's surface.