1.3.5 UK Weather Hazards

• Weather Hazards of the UK

  UK's climate

  • The UK has a mild, seasonal climate-cool, wet winters and warm wet summers.
  • Continentality, the North Atlantic Drift and air masses affect the UK weather.
• • Continentality:
  • Coastal areas are warmer in winter and cooler in summer 
  • Seas take up the heat in the summer, cooling the surrounding land
  • During the winter, the heat is released, keeping the coastal land warmer
• • North Atlantic Drift:
  • Ocean currents bringing warm waters from the Caribbean to the west coast of the UK
  • This keeps the west coast of the UK warmer than other regions of the UK
• • Air Masses:
  • Large volumes of air with similar water content and temperatures
  • Classified by the region where they form: 
  • Arctic or Polar cold air
  • Tropical warm air
  • Maritime wet air
  • Continental dry air
• • Five types of air masses that bring different weather to the UK:

  The UK's Air Masses

  -Air Mass- -Weather-

  Polar Maritime Cold and wet

  Arctic Maritime Very cold and wet

  Polar Continental Cold and dry

  Tropical Continental Warm and dry

  Tropical Maritime Warm and wet
• UK's extreme weather

  • Depressions:
  • Bring very wet and windy with unstable, low-pressure weather
  • Depressions form when warm air meets cold air
  • Form over the Atlantic Ocean, then move east over the UK
  • The strongest winds and heaviest rains are in the autumn due to sea waters releasing summer heat and meeting colder Polar air
• UK's extreme weather

  • Anticyclones:
  • Bring very cold or very hot, stable, high-pressure dry weather
  • Also, form over the Atlantic Ocean and move east over the UK
  • Winter anticyclones bring long periods of cold, foggy weather
  • Summer anticyclones cause periods of hot, dry, clear weather
• UK weather hazards

  • The UK experiences different weather hazards - rain, wind, heatwaves, thunderstorms, hailstorms, drought, snow and ice
• Types of Weather Hazards in the UK

  Rain

  • Flooding causes damage to homes, possessions, disrupts transport networks etc. 
  • Costs for recovery can cost millions of pounds
• Types of Weather Hazards in the UK

  Wind

  • Strong gales damage properties and cause general disruptions
  • Uprooted trees and debris can injure or kill
  • Winds are strongest in coastal areas - particularly the west coast and upland areas
• Types of Weather Hazards in the UK

  Heatwave

  • Long periods of extremely hot weather cause breathing difficulties, death and heat exhaustion
  • Pollution is held in the air as there is no wind to move it
  • Roads can melt and rails buckle under the heat, which disrupts transport
  • Tourism may benefit from good weather
• Types of Weather Hazards in the UK

  Thunderstorm

  • Heavy rain, lightning and strong winds
  • Most common in summer in the south and east of the UK
  • Lightning strikes can kill and can also cause fires and damage properties and the environment
• Types of Weather Hazards in the UK

  Hailstorm

  • Hailstorms usually occur with thunderstorms
  • Make driving difficult and can break windscreens
  • Can damage property
  • Destroy crops
  • Can kill if the hailstone is really large
• Types of Weather Hazards in the UK

  Drought

  • Water supplies run low
  • Causes economic impacts through loss of crops, death of animals, loss of wildlife etc.
  • People are affected by hosepipe bans and restrictions on water supplies
• Types of Weather Hazards in the UK

  Snow & Ice

  • Causes injury through slips and falls
  • Death through the cold
  • Schools, transport and business are impacted by closures
  • Cold snaps damage crops and wildlife
  • Farm animals can be killed in snow drifts 
• Worked example:

  State what is meant by extreme weather.

  Answer:

  • One mark for an appropriate definition:
  • Weather that is unexpected [1], unusual [1], severe [1], unseasonal [1], significantly different from the normal pattern [1] not normal to a particular area [1]
  • Weather (event) that can cause a threat to life [1]
  • Weather (event) that can cause damage (to property)[1]
  • No marks for rearranging the wording of the question or for quoting examples of extreme weather
  • No marks for saying 'different weather'
• Changes in UK Weather

  • The UK's weather is becoming more extreme
  • The Intergovernmental Panel on Climate Change (IPCC) has warned that temperatures will increase during this century
  • Global warming increases the frequency and intensity of extreme weather events through increased evaporation and rainfall
  • Scientists believe the UK will continue to experience higher amounts of rainfall and increased temperatures:
  • Since the 1980s extreme winter rainfall has increased
  • UK temperatures have increased by about 1°C since 1980.
• Changes in UK Weather (2)

  • Other examples of extreme weather in the UK include:
  • More frequent and heavier rainstorms, particularly in the autumn 
  • Gales
  • Flooding
  • Heatwaves
  • Droughts
  • Thick fog
  • Heavy snowfall
  • Temperatures have become more extreme in recent years
  • Unusually cold winters occurred in 2010-11 and 2014-15
  • Temperatures fell to -10°C with frost destroying crops and killing livestock
  • Over 17,000 trains were cancelled in 2014 due to the freezing conditions and flights were delayed
• Changes in UK Weather (3)

  • Frequent, heavy rainfall in autumn is followed by major flooding
  • The UK is regularly hit by depressions which bring heavy rain to the west coast of the UK
  • During the winter of 2013/14 there were prolonged Atlantic storms, with persistent rainfall and gale-force winds
  • Causing the Somerset Levels to experience unprecedented flooding 
  • Roughly 10% of the area was underwater at the height of the flood
  • Over 600 homes and 6880 hectares of agricultural land were flooded, along with a number of villages being cut off through flooded roads 
• Case Study: Extreme Weather in the UK

  Beast from the East 2018 

  • Background:
  • Began in January 2018 when the stratosphere suddenly warmed
  • This generated a large rise in air temperature of around 50°C in an area approximately 29km above the Earth at the North Pole
  • This sudden warming weakened the jet stream (which usually brings in the warmer air) and allowed the cold air from western Russia to 'flood' over Europe.
• Case Study: Extreme Weather in the UK

  • Social impacts:
  • Schools across the country were closed for up to 3 days
  • 10 killed across the country
  • Hundreds trapped in their cars on roads and motorways
  • The UK issued a gas deficit warning
  • Gas supplies were running low and thousands were without power
  • NHS cancelled non-urgent operations
• Case Study: Extreme Weather in the UK

  • Economic impacts:
  • The cost to the UK economy was estimated at least £1bn a day 
  • Shops, leisure facilities, theatres, cinemas and restaurants were severely impacted as people were told to stay indoors and not travel
  • Trains were stranded on tracks overnight, causing delays for many businesses
  • Thousands of businesses without or reduced power causing loss of earnings
  • Road closures meant workers and materials couldn't get through, forcing some businesses to close, whilst still accumulating costs
• Case Study: Extreme Weather in the UK

  • Environmental impacts:
  • Farmers lost crops and livestock during the freezing conditions
  • 15-20cm of snow fell over 3 days
  • Snow drifts of up to 7m in some rural areas of the UK
  • Temperatures dropped to -10°C with a wind chill of -22°C in some places
  • Wind speeds exceeded 70mph
• Case Study: Extreme Weather in the UK : Management strategies included:

  • Met Office issued Red Warning to stop people travelling.
  • Businesses asked to cut gas to keep homes heated longer.
  • Community centers opened shelter to homeless individuals to prevent further deaths from extreme temperatures.
  • Snow plows, gritters, and tractors to clear roads for travel.
  • Military rescued drivers & Transported NHS staff to aid sick.
  • Gregg's driver gave food to trapped drivers to avoid hunger.
  • Taxi firms aided elderly with grocery and medicine deliveries.
  • Red Cross provided blankets to Glasgow Airport stranded.
• Worked example:

  Which one of the following statements does not describe an extreme weather event in the UK?

  A: A snow blizzard in the Midlands

  B: A heatwave in the Lake District

  C: A tornado in the Isle of Wight

  D: A wet winter in western Scotland

  Answer:

  • D. A wet winter in western Scotland - this is normal weather in Scotland
  • No credit if two or more answers are identified