High and low pressure systems

What weather does low pressure cause?

Rainy and stormy weather

Where is the pressure the lowest on a weather map?

The centre

What does it mean if isobars are clustered close together on a weather map?

The pressure is quickly changing

What are low pressure systems also known as?

Depressions

What can low pressure cause?

Tropical storms

What can tropical storms only form in?

Deep bodies of water - at least 50 meters deep

What ocean temperatures do tropical storms form in?

27°C

How do tropical storms form?

Strong winds from upper atmosphere draw air from water surface

What direction does tropical storms move?

Westward - anticlockwise in southern hemisphere and clockwise in northern hemisphere

What distance and speed do tropical storms travel at?

600 km per day at speeds of over 120 kph

What happens to tropical storms when they hit land?

They loose energy and die out

How are high pressure systems formed?

By cold sinking air

What does high pressure cause?

No moisture to be drawn up meaning there are no clouds and only light winds

What weather does high pressure cause in the summer?

High temperatures

What weather does high pressure cause in the winter?

Frosty weather

Where is highest pressure on a weather map?

The centre

What does it mean if isobars on a weather map are widely spaced?

There is high pressure

What are high pressure systems also known as?

Anticyclones

What can high pressure cause?

Heatwaves and droughts over extended periods of time

What can droughts and heatwaves cause?

Wildfires, no electricity produced in hydroelectric dams, crops not growing and fish dying because of lack of oxygen