Transcript Fronts and Air Masses

BELL RINGER: NOVEMBER 6TH
• Explain how Pangaea relates to present day.
NOVEMBER 6, 2014
AGENDA
BELL RINGER
Intro to Fronts
Take a Bell Ringer
sheet and be prepared
to take some notes.
Cloze Notes
Ticket out the Door
AIR MASSES THAT AFFECT NORTH AMERICA
AIR MASS
A large body of air where temperature and moisture content are constant throughout
Air masses are characterized by their moisture content and temperature.
Characteristics of these air masses are represented on maps by a two letter symbol
COLD AIR MASSES
CONTINENTAL POLAR CP
In North America, Continental Polar (cP) air is formed over northern Canada, which
brings extremely cold winter weather to the United States. In the summer, a cP air
mass generally brings cool, dry weather.
MARITIME POLAR (MP)
An air mass that forms over the North Pacific Ocean is cool and very wet. This brings
rain and snow to the Pacific coast in the winter and cool, foggy weather in the
summer.
A mP air mass that forms over the North Atlantic Ocean brings cool, cloudy weather
and precipitation to New England in the winter and cool weather and fog in the
summer.
WARM AIR MASSES
CONTINENTAL TROPICAL (CT)
This air mass forms over the deserts on northern Mexico and the southwestern United
States. This air mass brings clear, dry, and hot weather in the summer.
MARITIME TROPICAL (MT)
The mT mass that develops over warm areas in the Pacific Ocean is milder that the
mP mass that forms over the Pacific ocean.
The mT mass that develop over the Gulf of Mexico and the Atlantic Ocean move north
across the East coast and into the Midwest. In the summer, they bring hot humid
weather, hurricanes, and thunderstorms. In the winter, they bring mild, often
cloudy weather.
FRONT
The boundary between air masses of different densities and usually different
temperatures.
COLD FRONT
Forms when cold air moves under warm air, which is less dense, and pushes the
warm air up.
Cold fronts move quickly and bring thunderstorms, heavy rain, or snow.
Cooler weather usually follows a cold front.
WARM FRONT
Forms when warm air moves over cold, denser air.
Warm air gradually replaces cold air.
They bring drizzly rain and leave behind clear and warm weather.
OCCLUDED FRONT
Forms when a warm air mass is caught between two colder air masses. The cold air
mass moves under and pushes up the warm air mass. The coldest air mass then
moves forward until it meets a cold air mass that is warmer and less dense. The
colder of these two air masses moves under and pushes up the warmer air mass.
An occluded front has cool temperatures and large amounts of rain and snow.
STATIONARY FRONT
Forms when a cold air mass meets a warm air mass. The difference with this front is
that both air masses do not have enough force to lift the warm air mass over the
cold air mass. So the two fronts remain separated. This leads to cloudy, wet
weather.
TICKET OUT THE DOOR
Last week, it was very warm and humid in the beginning. It then rained on
Wednesday. Afterwards, it was cool and dry. What kind of front came through last
week?