Air Masses, Fronts and MLCs

Weather Day to day conditions of the atmosphere driven by the heat from the sun and fueled

by the energy of water phase changes The weather is expressed in terms of its

elements: air temp, humidity, precipitation, air pressure, speed and direction of wind, cloud coverage

Changes in the weather

The US has the greatest variety of weather of any country in the world!

Associated with fronts, pressure zones, and air masses

What is an air mass?

Warm Front

Marked on a map by a red line with red semi-circles pointed towards the cool air

Generally associated with cirrus clouds followed by stratus/nimbostratus type clouds, (overcast skies), drizzle

Cold Front

Marked on a map with a blue line and blue triangles pointing towards the warm air.

cumulonimbus clouds along the front in the warm air, producing thunderstorms/heavy precipitation as well as severe weather at times (hail, tornados)

Occluded Front

Note: Warm air gets wedged between the cooler air causes clouds to form

Mid-Latitude Cyclones

Lows and Highs

High pressure=air falling=clear skies, clockwise rotation

Low pressure caused by lifting air Low pressure centers=“storm”,

characterized by counterclockwise rotation of wind, cloudiness, precipitation

Hurricane, mid-latitude cyclone, tornado

Practice Questions

What is North Carolina experiencing in terms of type of clouds based on this weather map?