3. What Are the Dominant Features of Weather Maps? ______

Now go to the web site:

3. What are the dominant features of weather maps? ______

Television and newspapers also often carry forecast weather maps which indicate how the weather patterns are expected to develop.Meteorologists use a wide range of information and techniques to formulate weather forecasts. The weather map does not and cannot show all of these factors. It is a fairly simple representation of past and probable future locations of surface weather systems (highs, lows, fronts, etc.). Nevertheless it provides a useful guide to the weather.

4. Who benefits from better understanding of weather maps? Why? ______

Go to the link What do weather maps show?

What do weather maps show?

The most obvious features of the media's weather maps (Figure 1 is an example) are the patterns of high and low pressure, and the barbed lines identifying cold fronts.

FIGURE 1.TYPICAL NEWSPAPER WEATHER MAP.

5. What way does air rotate around a low and high in the southern hemisphere? ______

6. How is wind strength indicated on a synoptic chart in most cases? In what way do tropical meteorologists indicate wind strength? ______

7. What do shaded areas on a weather map represent? ______

8. How is wind speed and direction shown on weather map? ______

Now click on link back to start at the bottom of the page, Go to the link Hot or cold?

Hot or cold?

Remembering that air flows clockwise around low pressure systems and anticlockwise around high pressure systems, this indicates a fairly typical summer weather map (Figure 2).

FIGURE 2.A SUMMER WEATHER MAP.

9. What do Northerly winds over eastern Australia carry in summer? What classic summer event do they carry? ______

10. What do moist, easterly winds over eastern Australia carry in summer? ______

The cold front passing South Australia replaces the hot, dry northwesterlies with southerlies carrying cooler, often relatively humid air from waters south of the continent. Such summer fronts are often quite shallow and may not penetrate far inland, particularly if they are distorted and slowed over the Victorian mountains.

In (Figure 3) a relatively common winter weather map shows:

FIGURE 3.A WINTER WEATHER MAP.

11. Very cold, unstable airfrom where will bring what type of temperatures and to which region?

______

12. Examining both Figure 2 and Figure 3, what difference do you notice about Summer Synoptic charts and Winter Synoptic charts?

______

Now click on link back to start at the bottom of the page, Go to link Rain or Fine?

Rain or Fine?

13. What is a cold front? What type of weather do they bring to a region?

______

14. What is a warm front?

______

Now click on link back to start at the bottom of the page, Go to link How strong will winds be?

How strong will the winds be?

A mean sea level pressure chart shows the direct relationship between isobar spacing (pressure gradient) and orientation, and the strength and direction of surface winds. The general rule is that winds are strongest where the isobars are closest together. Thus the strongest winds are usually experienced near cold fronts, low pressure systems and in westerly airstreams south of the continent. Winds are normally light near high pressure systems where the isobars are widely spaced.However, because of a latitude effect winds in middle latitudes are lighter than those in the tropics with similarlyspaced isobars.

15. Where are Australia’s most destructive winds generated from? ______

16. What are tropical cyclones. ______

The pressure gradient is very steep towards the cyclone's centre and wind speeds can be about 110 kilometres per hour with gusts 50 per cent or more above this mean wind speed. When the cyclone has moved inland it is cut off from its heat energy source, the ocean (it requires sea surface temperatures above 26.5 C), its intensity has decreased and wind speeds have dropped.

Now click on link back to start at the bottom of the page, Go to Using weather charts link

Using weather charts

17. What factors are used in the preparation of weather charts? ______

While predicted (prognostic) weather charts are essential to the forecast process, they must be interpreted by meteorologists to prepare specific weather forecasts and warnings. Forecast errors still occur, due to limitations in data or the forecast models, and the inherent complexity of the atmosphere, but forecast accuracy has increased very significantly since the introduction of satellite information and mathematical modelling. Prognostic charts shown routinely on television and in newspapers predict conditions up to three days ahead.

It will be realised by now that a single weather map is only a forecasting aid and that a great deal of other data and information must be gathered and processed before a forecast is issued.

Now access the site:

Click on Climate of Australia tab

18. Why is there a seasonal fluctuation in temperature for Australia? ______

Now click on Outline of Australian ClimateLink

Australia's climate is dominated by the dry, sinking air of the subtropical high pressure belt which moves north and south with the seasons. This causes the rainfall pattern over Australia to be strongly seasonal and helps to define the main climate regions. Use the main seasonal zone rainfall map to complete the table showing summary of rainfall zone and examples of cities in this zone.

Summer Dominant / Summer / Winter Dominant / Winter / Uniform / Arid
Summary of Rainfall Type
City Examples

Scroll down and complete the table showing major cities in Australia and their mean temperatures.

Mean Temperatures (°C) / Rain
January / July / mm
Location / Max / Min / Max / Min / Annual
Adelaide
AliceSprings
Brisbane
Canberra
Darwin
Hobart
Melbourne
Perth
Sydney

19. Using the above table, summarize the climatic conditions for Sydney and Alice Springs, why are they so very different? ______

20. Using the above table, summarize the climatic conditions for Perth and Hobart, why are they so very different? ______