CARDINALNEWMANCATHOLICSECONDARY SCHOOL

Name: ______Date: ______SNC 2D1

THUNDERSTORMS AND TORNADOES

Tornadoes can do more ______in a short time than any other storms on Earth because of their ______

Tornado paths are ______ and warnings of a strike in a precise area are given with ______

To understand tornadoes, we must understand ______

WHAT IS A THUNDERSTORM?

A thunderstorm is a storm with ______, ______, ______and sometimes ______

Two conditions must be met for a thunderstorm to form:

(1) ______is needed to form ______and ______

(2) The ______of the ______, or ______, must be very ______in order to produce ______that reach ______in the ______

Due to ______at a high altitude, ______air from lower down ______producing an ______or “active” circulation system

 The system gains strength if ______-level, ______speed winds (the jet stream) carry the rising air away quickly

______can be caused in various ways

(1)______of the air above the ground is ______and carry warm air ______

 If the air carries enough ______, a thunderstormdevelops

 This type of uplift is most severe on ______

 Occurs frequently in the ______United States and ______Ontario

(2) ______pushes ______upwards

 Water vapour ______and ______, releasing ______to warm the air further and making it rise higher

In the mature stage of a thunderstorm, several events occur:

(i) The ______cloud spreads to the top, reaching the ______in extreme cases

(ii) Cold air containing ______, ______and sometimes ______falls downward in large downdrafts

(iii)Repeated updrafts and downdrafts produce ______

(iv) ______and ______could occur

Lightning is a result of ______as ______carried in the updrafts collide with ______and ______in the downdrafts

 Most lightning discharges, called ______, take place within the storm clouds and appear as a ______between the ground and the cloud

In the final stage of the thunderstorm, the downdrafts ______the upward flow of air and the storm ______

DIAGRAM OF THE THREE MAIN STAGES OF A THUNDERSTORM

WHAT IS A TORNADO?

A tornado is a ______component of a ______in which a ______of air extends from the ______of the thunderstorm clouds to the ______

______air in a thunderstorm begin ______and forming a ______of air and moisture

As more rising air is ______by cooler air at the surface, the rotation becomes ______

The rising air causes a ______that ______with speed

 This pressure difference has the ability to ______roofs and carsand sends them ______

TORNADOES AND THEIR NUMBERS

At the centre of the tornado, known as the ______, wind speeds can reach up to ______km/h

The diameter of the funnel cloud can range from a ______to ______m

Tornadoes can last from only a ______to ______

They travel at speeds up to ______km/h, usually from ______to ______on ______

REFERENCE TABLE

STORM TRACKING

A ______is used by meteorologists to follow the development of thunderstorms and tornadoes

______are sent out from antennas are ______water drops and ice particles and some bounce back to the ______

 The ______reveal the location of the drops and particles, as well as their ______

THUNDERSTORM SAFETY

A ______is a safe place since it acts as a ______and charge from the lightning is carried directly to the ______

Never stand on top of ______and avoid ______such as fields and hills

It is fairly safe to be ______but avoid touching ______and ______

QUESTIONS

1. If you were looking at the sky, what evidence would indicate an approaching thunderstorm?

2. A convection current is stronger when the temperature difference between the bottom and top of the current is greater. Use this fact to explain why thunderstorms are much more common in spring and summer than in the winter.

3. If you take cover from tornado in a basement, the southwest corner is likely the safest place to choose. Why is this the case?

4. Look at the data on the Tornado Intensity Scale on the Page 4. Describe the relationship between the width of a tornado and its wind speed.