Air Parcel

• for an air parcel to rise, it must be warmer (and therefore, less dense) than the air around it

• once it starts to rise, it cools

  • increases air parcels relative humidity

    • absolute humidity stays the because that is just the total amount of water vapor in the air

• when an air parcel reaches a relative humidity of 100%, it’s saturated with water

  • this is called the dew point

• once the air parcel cools lower than the dew point, the water will condense and precipitation will occur

• this condensation causes energy to be released as latent heat

• as an air parcel rises through the atmosphere, the relative humidity will increase

Storms

• when two air masses (one cold and one warm) collide, a severe thunderstorm is produced

• air-mass:

  • key criteria required to form it:

    • inflow of warm, moist air (like tropical climates or late afternoons in the summer)

  • characteristics that differentiate it from other thunderstorm types:

    • local thunderstorms and only last for a short amount of time

• severe:

  • key criteria required to form it:

    • two air masses (a cold and warm front) collide to cause more intense updrafts of warm air and resulting downdrafts of cold air

  • characteristics that differentiate it from other thunderstorm types:

    • must have either:

      1. high winds (>58 mph)

      2. large hail (at least 1” diameter)

      3. generate a tornado/tornadoes

• supercell:

  • key criteria required to form it:

    • extremely large updrafts of warm air

    • rotation of the updrafts to create a vortex

  • characteristics that differentiate it from other thunderstorm types:

    • rotation of the updrafts and tilting of the storm are key criteria that differentiate it from a severe thunderstorm