Air Masses & Fronts
Changes in weather are primarily caused by the movement and interaction of these large bodies of air.
Air masses
A large blue "H" on a weather map indicates this type of system, which usually brings clear skies and fair weather.
High Pressure
Because the Earth is a sphere, the Sun does this to the surface, which drives our global weather patterns.
Heats it unevenly
If natural hazard experts want to protect people in the Midwest from these severe, rotating storms, they might propose a plan to text residents alerts to take shelter underground.
Tornadoes
When two large bodies of air with different temperatures and humidity levels meet, the boundary between them is known as this.
Between cold air and warm air, this one has a higher atmospheric pressure because it is denser.
Cold Air
In Earth's global wind patterns, warm air near the equator is less dense and does this, while colder air near the poles is denser and sinks.
Rises
On a weather map, these black lines connect regions that are experiencing similar atmospheric pressure.
Isobars
If advancing cold air is colder than the air it is replacing, it forces the warm air up and is known as this type of front.
Cold Front
Meteorologists use this specific instrument to measure changes in atmospheric pressure.
Barometer
Coastal cities often have cooler daytime temperatures than nearby inland cities because water does this compared to land.
Heats up more slowly
If the isobars on a weather map are drawn very close together, it indicates that the pressure is changing rapidly, meaning the weather will change at this speed.
Very quickly
When a fast-moving cold air mass crashes into a slow-moving warm air mass and forces the warm air to rise rapidly, it is most likely to bring this type of weather.
Heavy rain and thunderstorms
If a local weather station reports that atmospheric pressure is dropping quickly and humidity levels are rising, it means this type of weather is likely approaching your town.
A storm
When relative humidity reaches 100 percent overnight, this happens to the water vapor in the air, creating visible moisture like dew on the grass.
Condensation
An increase in average temperatures leads to more solar energy reaching Earth's surface, which speeds up evaporation and condensation, causing an increase in these short, extreme events.
Severe thunderstorms/flash floods.
When a warm air mass moves into a region to replace a cold air mass, the warm air will do this, which causes it to condense into clouds.
Rise above the cold air
If you were to climb down from a high mountain peak, you would experience these two changes in the atmosphere as you got closer to sea level.
Increasing air density and increasing atmospheric pressure
In a model of how Earth's surface water becomes precipitation, the Sun acts as the energy source causing this phase change from the lake to the sky.
Evaporation
Engineers designing a home in the southeast United States might use reinforced glass and a wheel-spoke design to lessen the impact of the wind and floodwaters from these massive coastal storms.
Hurricanes