2.3

1. hail with a diameter of 2 cm or more, wind gusts of 90 km per hour or more, flash flooding and tornadoes

2. lightning strikes

3. warm humid air that is pushed up into the atmosphere by converging surface winds

4. when the air rises the moisture and then condense releasing heat energy

5. when the water freezes forming ice crystals potentially making hail

6. they are most likely to form in the clouds

7. the bureau of meteorology

8. because they can form in minutes and form faster than we can predict it.

9. a) 13 November 2006
    b) Sydney, Newcastle and Wollongong
    c) 2:10
    d) get to a safe place