Air Pressure and Weather

We will identify how global patterns of atmospheric movement influence local weather using weather maps that show high and low pressures and fronts.

Rain – liquid precipitation in the form of water drops that falls from clouds.

Snow – precipitation that is made up of ice crystals.

Sleet – solid precipitation in form of ice pellets.

Hail – frozen spheres of precipitation; much larger than sleet pellets.

Sunny – very few clouds in the sky.

Partly Cloudy – more sun than clouds.

Cloudy – thick cloud cover that blocks the sun.

Warm Front – The boundary between two air masses where a warm air mass is replacing a cold air mass.

Cold Front – The boundary between two air masses where a cold air mass is replacing a warm air mass.

Stationary Front – a pair of air masses, neither of which is strong enough to replace the other; moves very slowly.

Occluded Front – a combination of two fronts that forms when a cold front catches up and overtakes a warm front.

High Pressure System – pressure that brings clear, sunny skies, cooler temperatures, and calm weather; represented by the symbol “H” on a weather map.

Low Pressure System – pressure that brings cloudy skies, warmer temperatures, and precipitation; represented by the symbol “L” on a weather map.