LEAD-TO-LEARN
INVESTIGATING THE GENESIS AND MAINTENANCE OF SQUALL LINES AND ASSOCIATED BOW ECHOES
WORK SHEET
Introduction
In this activity you will interact with model output and local observations to investigate the birth and propagation of a typical squall with an embedded bow echo. You will use a case study that covers the event that occurred on 11 March 2006 in Illinois .
Objectives
By the end of this module you should be able to:
Background
Squall lines are a line of thunderstorms that contains contiguous precipitation areas. They are usually associated with a cold front, which means they can be produced in most areas of the country. Many factors lead to the formation and maintenance of squall lines, including shear, line-end vortices, and the initiation of new cells due to interactions between squall line cold pool and the outer environment. Such squall lines can sometimes become so intense that the winds that feed in from the rear of the storm, which are collectively referred to as the Rear Inflow Jet (RIJ), can cause the center of the line to bow outward. This type of signature on radar likely indicates areas of damaging wind. These and related factors are explained in more detail in the following sections:
1) Environmental Conditions/Instability
2) Early
Development
3) Mature/Bow Echoes
4) Horizontal Propogation
Loading the IDV Bundle
Click on the link to the bundle squall_line.jnlp. Two main windows should appear: The Display Window and the Data Selector Window. Various Parameter Windows will also appear. When you have the bundle loaded, go to the next section.