Transcript earth science - cloudfront.net

CHAPTER 20
WEATHER
20.2
Fronts and Lows
12/4 DAILY QUIZ
• 1. What is an air mass?
• 2. Give the characteristics of each air mass
below
a.cA
b.mP
c.cT
d.cP
e.mT
20.2 Fronts and Lows
Section 20.2 - Agenda
• What is a Front?
• Types of Fronts
- Warm
- Cold
- Stationary
- Occluded
• Life cycle of a Mid-Latitude Low
What is a Front?
• The boundary that separates
different air masses.
• Usually bring:
1.Changes in Temperature
2.Changes in Wind Direction
3.Changes in Humidity
4.Precipitation
1. Cold Front
•Advancing Cold Air
•Forces Warm air up at a Steep slope
•Usually a narrow band of precipitation
•Cumulonimbus Clouds
COLD FRONT
Warm
Cold
Air
2. Warm Front
•Advancing Warm Air
•Warm air rides over cold air at a low
slope
•Usually a wide band of precipitation
•Brings thinner, layered clouds
WARM FRONT
Warm Air
Cold Air
Vis 2002
3. Occluded Front
•Cold Front catches up to Warm Front
since cold fronts move twice as fast.
•Warm air is squeezed up, forming clouds.
4. Stationary Front
•Front is not moving.
•Warm air still rises above cold air,
bringing clouds and precipitation.
•Can lead to flooding.
Life Cycle of a
Mid-Latitude Low
•Fronts are usually connected to Low
Pressure systems.
•As the Low spins, the fronts move and
the Cold front catches up to Warm.
•Takes 12 to 24 hours to get to stage 3.
Upper Air Flow steers the Low along
Upper Air Flow
Weather associated with Pressure
Systems
As a Low moves near, the weather will
A
change.
B
C
LAST PORTFOLIO
DECEMBER 17, 2012
TITLE:
Name:
BIG IDEA
THINGS I HAVE
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UNDERSTAND
THE BIG IDEA
OTHER THINGS I
COULD ALSO
KNOW
11/16 TODAY…
Stamp Homework
Tonight’s Homework
FINISH WORK STARTED IN CLASS
Read Section 19-1, 19-2
Answer Section Assessment 19-2 & 19-2
Answer Worksheets 19-1 & 19-2
Complete Chapter 19.1.19.2 Powerpoint Notes
Daily Quiz
Worksheet 19-4 and 19-4