| A | B |
|---|
| Air mass | a large body of air that has properties similar to the part of the Earth over which it forms. |
| Alto | a prefix given to mid-altitude clouds. |
| California current | a cold ocean current that flows down along the west coast of the U.S. |
| Cirrus | wispy clouds consisting of ice crystals that form at high altitudes. |
| Cirro | a prefix given to high-altitude clouds. |
| Climate | average weather pattern in an area over a long period of time. |
| Climate zones | divisions of the Earth's climates into general zones according to average temperatures and average rainfall. |
| Cold front | when a cold air mass collides and pushes under a warm air mass, resulting in thunderstorms and sometimes tornadoes, followed by cooler temperatures. |
| Cumulonimbus | a vertically oriented clouds that can produce lightning and hail, also known as a ‘thunderhead’. |
| Cumulus | puffy clouds with flat bottoms that form at low altitudes. |
| Eye of a storm | the center of a storm, which has low air pressure and is usually calm. |
| Fog | stratus clouds that form when condensation occurs at or near the ground. |
| Front | a boundary between two air masses of different temperature, moisture, or density. |
| Gulf stream | a warm ocean current that flows up along the east coast of the U.S. |
| High pressure system | a region of sinking, cool air that signals fair weather. |
| Hurricane | a low pressure tropical storm system that forms over warm ocean water. |
| Low pressure system | a region of rising, warm air that signals the formation of clouds and/or precipitation. |
| Nimbus | a prefix (nimbo-) or suffix (nimbus) that means ‘dark, precipitation’. |
| Ocean surface currents | convection currents that circulate warm and cold ocean waters which influence the weather and climates of the land masses nearby. |
| Occluded front | when a cold air mass pushes into a warm air mass that is behind a cool air mass, the warm air mass is pushed up above the cooler air masses. This results in long periods of precipitation, followed by cooler temperatures. |
| Polar zone | a climate zone that is located at the poles and has cold temperatures year-round. |
| Stationary front | When neither a cold air mass nor a warm air mass moves at a frontal boundary, resulting in a long period of precipitation. |
| Stratus | spread out or layered clouds that form at low to medium altitudes. |
| Temperate zone | a climate zone that is located in the mid-latitudes which has cold winters and warm summers (seasons). |
| Thunderstorm | a storm with thunder, lightning, heavy rains and strong winds, which forms within large cumulonimbus clouds. |
| Tornado | a rapidly whirling, funnel-shaped cloud that extends down from a storm cloud. |
| Tropical zone | a climate zone that is located near the equator and has warm temperatures year-round. |
| Warm front | when a warm air mass collides and rides over a cold air mass, resulting in long periods of precipitation, followed by warmer temperatures. |
| Weather | the condition of Earth’s atmosphere at any given time. |
