ATM OCN (Meteorology) 100
MIDLATITUDE WEATHER SYSTEMSPART II: THE EXTRATROPICAL CYCLONE
Lectures # 20 and 21-A Scheduled for:
20 JUL 2004 (T)
21 JUL 2004 (W)
Recommended Readings from Moran (2002):
Today's Lecture Objectives:
- To describe briefly the contribution made to meteorology by the Norwegian School with the polar front cyclone model.
- To identify the relative size and characteristics of an extratropical cyclone.
- To locate and describe the general temperature-field, the wind regime and the cloud and precipitation pattern associated with a model extratropical cyclone.
- To locate the regions of greatest pressure change with respect to time in a migratory extratropical cyclone.
- To outline the sequence of stages in the life cycle of a migrating midlatitude wave cyclone.
- To relate the features associated with a surface extratropical cyclone and the upper tropospheric wind regime.
- To identify regions of cyclogenesis and the major storm tracks across North America.
- To distinguish between warm frontal weather and cold frontal weather and their associated weather sequences during frontal passage.
- To describe the weather sequences (i.e., changes in wind direction, pressure tendency, cloud type and coverage, precipitation and temperature) when the warm or cold side of a wave cyclone passes an observer.
- To locate the position and forecast the movement of an extratropical storm by interpreting the sequence of wind direction, pressure change, temperature change and cloud/precipitation type at a station.
- To identify the hazards associated with winter storms and define the forecasting terms used to describe them.
Series continues from Midlatitude Weather Systems: The Setting, Air Masses & Fronts
- Practical Problems
- Historical Perspective
B. THE NORWEGIAN or POLAR FRONT (WAVE CYCLONE) MODEL
- Designation of Extratropical Cyclones
- Distinguishing Features of a Mature Polar Front Cyclone
C. OBSERVED WEATHER FEATURES SURROUNDING THE CYCLONE
- Pressure Fields & Pressure Tendency Fields
- Wind Fields
- Temperature Fields
- Cloud Fields
- Precipitation & Other Significant "Weather" Events
D. LIFE CYCLE OF AN EXTRATROPICAL WAVE CYCLONE -
"THE OCCLUSION PROCESS"
- Storm Formation (or cyclogenesis)
- Early Developing Stage
- Mature Stage
- Occluding Stage
- Occluded Stage
E. OTHER FEATURES OF THE POLAR FRONT CYCLONE MODEL
- Cyclone Families
- Energetics of Cyclogenesis - The Driving Force
- Regions of Cyclogenesis
- Limitations and Complications of the Polar Front Model
F. MOVEMENTS OF EXTRATROPICAL WAVE CYCLONES
- General Movements
- Principal Cyclone Tracks over North America
- Time Sequences of Weather Events - Single Point Forecasting
G. WINTER STORMS
- Winter Weather Conditions
- Hazards of Winter Storms
- Ingredients of Winter Storms
- Public Information Dissemination and Public Safety Precautions
Unit continues as Midlatitude Weather Systems: Anticyclones
Links to Other References:
Latest revision: 3 August 2004 (0400 UTC)
Produced by Edward J. Hopkins, Ph.D.
Department of Atmospheric and Oceanic Sciences
University of Wisconsin-Madison Madison, WI 53706