Fronts

Front: boundaries of air masses Differ by temperature, density, and humidity

• The weather we experience depends on which front is dominant 
• Fronts bring precipitation

• A Cold air masses pushes a warm air mass upward
• The air & weather becomes cooler
• Heavy precipitation and storms follow
• Tall cumulonimbus clouds form because the wind is pushing air & water vapor upward

• A warm air mass overtakes a cold air mass
• The temperature warms as cold air is pushed back
• Water vapor causes high humidity
• Precipitation is milder (ex. drizzles)

• A warm and cold air mass meet trying to move in opposite directions
• Neither is moved
• Heavy storms & precipitation can last for days

• A warm air mass is caught between 2 cold air masses
• Cold air masses rise over the warmer
• Strong winds and heavy precipitation result