Conditions That Change Weather

Air Masses and Jet Streams

• The rotation of the Earth causes the creation of jet streams, which cause wind and storms. Jet streams are what cause cold fronts, which are brought in from the Earth's poles by clouds, the Weather doctor reports. Similarly, warm air is brought forth from the equator to the poles, causing rainfall and warmer temperatures to northern regions. Jet streams bring together pressurized air masses, which are what cause the weather changes from season to season.

Barometric Pressure

• Barometric pressure, also known as atmospheric pressure, drops as altitude is increased. It's measured by the weight of the air above a certain point, the Weather Network says. As altitude and barometric pressure increases, skies will become fair. As altitude and barometric pressure decreases, skies will become overcast, which may lead to precipitation. Weather conditions vary depending on altitude and location.

Humidity

• Humidity can be placed in to two categories; absolute and relative, the Weather Doctor says. Absolute humidity refers to the amount of water vapor in the air and is unchanging. Relative humidity, the ratio between the water vapor in the air and the saturation vapor pressure for the air's temperature, can vary throughout the day. Humidity affects precipitation and may aid in the creation of storms or even tornadoes.

Global Warming

• Global warming is a phenomenon thought to be brought on by the burning of fossil fuels, which heat up the planet due to another phenomenon called the "greenhouse effect." It is estimated that by 2030, temperatures all over with world will increase by 2 to 3 degrees, the Climate Change website reports. Due to the melting of ice caps, scientists predict that precipitation will continue to increase, causing sea levels to rise and in turn causing an increased number of storms.