Weather

• What affects the UK's climate?

  Altitude - distance from sea level (1 degree lost per 100m)

  Aspect - South facing slopes receive more sunlight

  Distance from the sea - Summer the land is warmer, winter sea is warmer

  Latitude - the distance from the equator
• What air masses affect the UK?

  Polar Maritime

  Arctic Maritime

  Tropical Maritime

  Tropical Continental

  Polar Continental
• What weather does polar maritime air mass bring?

  Cold and wet conditions year round
• What weather does Arctic maritime air mass bring?

  Cold wet weather in the north, cold and dry weather in the south.
• When does the Arctic maritime air mass affect the UK?

  Only in winter
• What weather does the Polar Continental air mass bring?

  Hot dry weather in summer

  Cold dry weather in winter
• What weather does the Tropical Maritime air mass bring?

  Mild wet weather in summer and winter
• What weather does the Tropical Continental air mass bring?

  Hot dry weather in summer only
• What are the three types of rainfall?

  Relief rainfall

  Frontal rainfall

  Convectional rainfall
• What is relief rainfall?

  Rainfall that occurs when moist air is forced to rise over elevated terrain, causing it to cool and condense into precipitation. The cool air is heavier and denser than the warm air so it starts to sink
• What is frontal rainfall?

  Frontal rainfall is precipitation that occurs when warm and cold air masses meet, causing the warm air to rise and cool, leading to condensation and the formation of rain.
• What happens at a front?

  If cold air meets warm air, the colder air will undercut the warm air, forcing it upwards. Where air is rising, air pressure drops. Air rushes in

  from nearby areas that have a surplus of air. This movement

  creates wind. Fronts therefore bring precipitation and wind.
• What is convectional rainfall?

  Rainfall that occurs when warm air rises, cools, and condenses into clouds, which then produce precipitation.
• What is a depression?

  They are low pressure weather systems that usually bring persistent rainfall that at stages can be heavy rainfall and strong winds.
• What happens at stage 1 of a depression?

  Stage 1 is the warm front. The warm air rises and cools and condenses into clouds which brings long periods of steady rain. Wind then increases as the warm air rises. This is because air pressure is

  dropping. Air from high pressure areas with surplus air moves in to fill the gap created by the rising air. The movement of that air from a high pressure to low pressure area creates wind. Those winds move in from the SW.
• What happens in stage 2 of a depression?

  It is the warm sector. This is the area of warmer air behind the warm front. Here the warm air is not in contact with any cold air. This means that less air is rising. As less air is rising, less cloud is being produced. This causes the rain to become lighter or stop altogether. As less air is rising, winds also drop. The wind direction changes to westerly.
• This is the Cold front
• Cold front

  • Marks the front of an area of air that is colder than the air ahead of it
  • Warm and cold air cannot mix
  • Where warm air and cold air meet, the warm air has to rise over the cold air
  • Cold air moves faster than warm air and the cold air of the cold front has caught up with the milder air at the warm sector
• As the cold front moves in

  1. Wind direction suddenly changes from westerly to north-westerly

  2. This sudden changes of wind direction causes gusty winds to form

  3. The cold air undercuts the warm air (it pushes it up) very quickly

  4. This causes large cumulonimbus clouds to from that bring heavy rain

  5. As the cold front moves away the rain becomes lighter and then turns to showers
• What are anticyclones?

  They are high pressure weather systems
• Traits of anticyclones in summer

  • little to no cloud
  • lack of cloud cover means a large amount of sunlight reaches the earths surface, making it very hot
  • Long dry periods
  • they end with a thunderstorm
• What effect do anticyclones have in summer?

  • due to the lack of precipitation, there is drought
  • this causes farmers crops to fail leading to a loss of profit
  • people suffer from heatstroke and sunburn
• Traits of anticyclones in winter

  • the lack of cloud makes it very cold
  • the cold conditions at night create frosty conditions during the day
  • This can last throughout the day even when the sun is out. This is because in the winter the sun’s rays hit the Earth’s surface at a lower angle. This means that they are less intense
  • the days are often foggy
• What effect to anticyclones have in winter?

  • The persistent frost causes road accidents due to the slippery conditions
  • crops may fail due to the low