Weather Hazard Revision Key Idea

Global atmospheric circulation helps to determine patterns of weather and climate.

What you should know • General atmospheric circulation model: pressure belts and surface winds. The General Atmospheric Circulation Model General Atmospheric Circulation Model • To understand the General Atmospheric Circulation model you first of all need to understand: ​ • Why variations in solar energy exist ​ • How variations in solar energy cause high and low air pressure ​ • How areas of high and low air pressure cause wind ​ • The impact of the Coriolis Effect on wind ​ Why variations in solar energy exist

The Earth’s surface receives the highest amount of solar radiation at the Equator. This is because the energy is spread over a smaller area and travels a shorter distance through the atmosphere at the equator. These are both as a result of the curvature of the Earth and its atmosphere • So how do the different temperatures at the Earth’s surface create different air pressures around the earth?​ ​ To understand this think about the following…

Low Pressure Moist rising air • Air is rising as it is warmer than surrounding air and warmer air is less dense (lighter) ​ • This leads to less air particles resting on the earths surface and so creates an area of low pressure ​ • As the air rises it cools, so water vapour condenses and causes cloudy, rainy conditions. ​ • It creates unsettled weather conditions

High pressure

• Air is sinking as it is cooler than surrounding air and cooler air is denser (so is heavier)​ • This leads to more air particles resting on the earths surface and so creates an area of high pressure​ • This means condensation does not occur and so leads to clear skies and settled conditions

Dry sinking air How areas of high and low air pressure cause wind ​

• The Earth's atmosphere exerts a pressure on the surface of the Earth. ​ • Pressure is measured in millibars. Standard pressure at sea level is defined as 1013mb, but we can see large areas of either high or low pressure

Wind always moves from high to low pressure • The earth tries to balance air pressure, so air from higher pressure areas moves into low pressure areas. This movement of air is what we know as wind. ​ • Areas of low pressure have higher wind speeds as wind rushes in from surrounding areas. So, not only is it cloudy and wet in areas of low pressure it is windy too. ​ ​

Global cloud patterns are linked to the distribution of low and high pressure systems that separate the convection cells What is the Coriolis effect?

• The effect on wind caused by the spinning of the Earth • On a non-rotating earth air flow between high and low pressure areas would generate one convection cell per hemisphere ​ ​ ​ • On a rotating earth the ‘Coriolis Effect’ causes atmospheric circulation to be divided into three cells per hemisphere (Hadley, Ferrel, Polar Cells) ​ ​ ​ The link between High and low pressure and surface winds

How does the global circulation influence surface wind patterns • The three cells Hadley ,Ferrel and Polar cells influences surface and high level winds as they transfer the energy received from the sun in the atmosphere. Sub tropical high pressure • The sub tropical high pressure areas move toward the low pressure areas near the equator. • The rotation of the earth produces the Coriolis effect which deflects the winds to the right in the northern hemisphere and left in the southern. • This leads to prevailing winds ie westerlies in the uk.

Relationship between Tropical Storms and the General Atmospheric Circulation • Tropical storms originate (begin) in warm ocean waters close to the equator because this area receives the greatest concentration of energy from the sun, this energy warms the oceans to 27°c that’s needed for tropical storms to form.​ • Tropical storms occur between 5° and 20 ° North or south of the equator because the Coriolis Effect is great enough to cause the storm to spin​.to close to the equator not enough spin • They begin at an area of low pressure, that means the air is rising, cooling and condensing to form clouds. As more and more air rises and condenses the clouds get thicker and lower in the sky and a storm will begin to develop.​

• Air blows into the low pressure systems from the Tropic of Cancer and Tropic of Capricorn which are 30° north and south of the equator, this is where the high pressure belts lie.​ ​

• The air moving from high to low pressure generates winds called the trade winds, these converge (come together) and meet which causes the storm to spin​

Key Idea Tropical storms (hurricanes, cyclones, typhoons) develop as a result of particular physical conditions. What you should know • Global distribution of tropical storms (hurricanes, cyclones, typhoons). • An understanding of the relationship between tropical storms and general atmospheric circulation. • Causes of tropical storms and the sequence of their formation and development. • The structure and features of a tropical storm. • How climate change might affect the distribution, frequency and intensity of tropical storms Causes of tropical storms

• light winds aloft (above) • winds near the ocean surface blowing from different directions converging • low-wind-shear winds that do not vary greatly with height (so storm not broken up as it forms) Global distribution of tropical storms (hurricanes, cyclones, typhoons).

Global distribution of tropical storms (hurricanes, cyclones, typhoons). • Could be asked to describe the distribution • Start large work in finish with anomalies • Most tropical storms occur between 5°and 20° north and south of the equator • Tropical cyclones occur more frequently in the northern hemisphere where 69% occur • Where as in the southern hemisphere 31% occur this is 25% less than the northern hemisphere • 33% of all tropical cyclones occur in the western Pacific the where they receive 16 % more than in the East Pacific which has the second highest frequency at 17% sequence of tropical storms formation and development.

How tropical storms are formed

• They contain enormous amounts of energy captured from the atmosphere and moisture from the oceans • Areas they form are characterised by low pressure and rising air • Results in a strong up lift of very moist warm air • Warm air rises in a spiralling motion drawing up huge amounts of evaporated water which cools and condenses quickly to form tall towering banks of clouds • Vast amounts energy is produced • This energy powers the storm • As storm builds more water vapour is drawn in and upwards • Clouds grow larger wind speeds increase heavy rain fall increases • Storms increase their power /energy as they move over water • Lose energy as its moves over land

How do storms lose their energy

• The frictional effect of moving over the land, eg they pass over land which slows their movement due to friction. • Loss of energy due to cooling effect of passing over water (or land) at higher latitudes, eg they move into areas of cooler water, where there is less energy. The structure

The Features of a Tropical Storm How can you tell the winds are anticlockwise • Figure 4 shows that the pattern of winds moving around the hurricane centre was anticlockwise because the clouds show an anticlockwise pattern/the clouds spiral inwards/of the way the clouds are arranged (1) How climate change might affect the distribution, frequency and intensity of tropical storms

Changing DISTRIBUTION of tropical storms (where they happen)

1. How much have the surfaces of our seas warmed by? . Over the last few years, as our climate is warming, sea surface temperatures have increased by 0.25-0.5°C

1. What impact might this have on the distribution of storms? . Cold ocean temperatures keep waters below the temperature needed (27°C) for tropical storms to develop. As ocean temperatures are warming tropical Storms may begin affecting areas further north and south of the equator, areas that were once too cold for tropical storms to form.

1. Is there any evidence to suggest this has already started to happen? Hurricane Catarina moved into the Brazilian state of Santa Catarina on 28 March 2004. Hurricanes do not normally form in the South Atlantic, it was the first ever recorded here, and coastal communities were taken by surprise.

Increasing INTENSITY of Tropical Storms (how strong they are)

1. Describe the overall pattern of hurricane intensity in the Graph C North Atlantic, shown by Hurricane Intensity in the North Graph C Atlantic, 1951- 2011 . Graph C shows hurricane intensity in the North Atlantic decreased overall during the period between 1950 and the early 1980s, from just over 3 on the index scale to 1. It then increased overall in the period between about 1983-2005, reaching its peak at almost 5.5 on the index scale. However, by 2011 it was almost the same as the 1950s level again, at just under 3 on the index scale intensity

1. What reason do some scientists give for the increase in the intensity of tropical storms, which could be linked to climate change? . Some scientists say this is linked to the increase in sea surface temperature. The higher sea temperature the more water is evaporated and atmosphere above is warmed. This will increase convection (warm air rising), creating lower surface pressure, and therefore leading to stronger, more intense winds.

1. Not all scientists agree that tropical storm intensity is increasing. What do they say is needed before we can be sure? . Some scientists say that more data is needed over a long time period to say for sure that storm intensity is increasing. Frequency

• Increasing FREQUENCY of Tropical Storms (how many happen) • Is there any evidence to suggest that there has been an increase in the number of tropical storms happening? • In July 2007, a survey of hurricanes in the North Atlantic over the past century (100 years) noted an increase in the number of observed hurricanes. • • How could increasing ocean temperatures, as a result of climate change, lead to an increase in the number of tropical storms? • Some Scientists argue that an increase in ocean temperature will increase evaporation and convection rates, therefore increasing the number of tropical Graph A storms • Some scientists argue that the increase in the number North Atlantic Tropical Storms and Observing Techniques of tropical storms recorded might not actually be due to climate change. What other reason do they give that could explain the increase instead? • Some scientists argue that the reason a greater number of tropical storms are being observed may be due to an improved ability to observe them, thanks to aircraft, radar and satellites (as indicated at the top of Graph A), rather than actually being as a result of climate change. • Some scientists argue that the number of tropical storms will decrease in frequency as the climate gets warmer. What reason do they give for this argument? • Scientists argue that increasing temperature leads to an increase in vertical wind shear (Definition: Wind shear is the change in speed or direction of wind over a relatively short distance or time period). A strong vertical wind shear can tear a tropical storm apart, so they believe tropical storms may become less frequent as global temperatures increase

Key Idea

Tropical storms have significant effects on people and the environment

What you should know

• Primary and secondary effects of tropical storms. • Immediate and long-term responses to tropical storms. • Use a named example of a tropical storm to show its effects and responses. • How monitoring, prediction, protection and planning can reduce the effects of tropical storms.

Effects of tropical storms.

Sequence of weather as storm approaches over 24 hours • Cloud cover will increase over the next few hours and wind speed will pick up dramatically as the outer part of the vortex approaches. • Winds, which will be blowing from the east, may be damaging and there will be torrential downpours of rainfall from dark cumulonimbus clouds. There is a possibility of tornadoes and thunderstorms with lightning. A storm surge combined with the heavy rain may cause dangerous flooding in low-lying coastal areas. Air pressure will drop rapidly. • This will be followed by the centre of the storm or ‘eye’, which will only last for a short time. The weather is likely to be fairly calm with only light or no wind winds mostly clear skies, little or no rain and fair weather. • The winds will again increase suddenly as the second part of the vortex approaches. This will be accompanied by powerful winds blowing from the west, with further heavy rain. Air pressure will rise as the storm continues northwards, and cloud cover will then become thinner, with more moderate winds. Eventually the rain will cease, although further belts of showers will occur as the storm moves away. Typhoon Haiyan named example

The Typhoon hit the Philippines in November 2013 The Typhoon was a category 5 storm of the Saffir Simpson scale Winds up to 170mph devastated several towns, the city of Tacloban was worst hit. • Waves up to 15m high destroyed huge areas of coastline

• It was one of the strongest storms ever recorded. At times it stretched 600km (372 miles) across. If the same storm was placed over a map of Europe it would stretch from London to Berlin

Most of the destruction was caused by the storm surge. This is a wall of water similar to a tsunami. The very low pressure associated with the typhoon caused the level of sea rise. As strong winds swept onto the shore, it formed a wall of water several metres high. Primary effects

• 6300 people killed, most drowned by the storm surge • 40,000 homes damaged or completed destroyed • 90% of Tacloban city was destroyed, again mainly by the storm surge • Tachloban airport terminal was badly damaged • 30,000 fishing boats were destroyed • Strong winds damaged buildings and power lines • Crops were destroyed by the strong winds and storm surge • 400mm rain caused widespread flooding • Sizable trees just bent over and thrown about like matchsticks

Secondary effects

• 14 million people were in some way effected by the storm, many left homeless. • 6 million lost their source of income • Heavy rain caused flooding and landslides that blocked roads, cutting off remote communities • Power supplies were down for a month • Flights were disrupted for weeks, slowing down aid efforts • There were shortages of food, water and shelter, leading to outbreaks of disease • Hospitals, shops and schools were destroyed affecting people’s livelihoods and education • Looting and violence broke out in Tachloban

Immediate Responses

• International government and aid agencies responded quickly with food, water and temporary shelter • US aircraft carrier ‘George Washington’ and helicopters assisted with search and rescue and delivery of aid • 1200 evacuation centres set up to house the homeless • French, Belgian and Israeli field hospitals set up • Philippines Red Cross delivered food (rice, canned food, sugar and cooking oil) • UK send shelter kits, to provide emergency shelter for a family.

Long-term Responses

• The UN and countries including the UK and US donated financial aid, supplies and medical support • Rebuilt roads, bridges and airport facilities • ‘Cash for work’ programmes, people were paid to help clear the debris and rebuild the city • Rice farming and fishing quickly re-established • Coconut trees destroyed after the storm are being planted, but it will take seven years for them to bear fruit. • Oxfam supported the replacement of fishing boats • Thousands of homes rebuilt in areas away from flood risk • More cyclone shelters built

Using a named example, evaluate the immediate and long-term responses to tropical storms. • The command is to “evaluate”, which means to consider a mix of responses to tropical storms and weigh them up so as to come to a conclusion about their effectiveness, degree of success or validity. Suggested responses • Responses to storms should be categorised into immediate and long-term. Strategies adopted may depend on the types of effects: social, economic or environmental. Responses to storms may vary depending on whether the impacts are primary or secondary. Credit distinctions between responses in HIC and LICs/NEE countries and between urban and rural settings • Understanding of human factors affecting responses: population density, urbanisation of the population, poverty, strength of infrastructure, education, effectiveness of government, disaster planning. • Understanding of physical factors affecting responses: intensity of the storm, speed of movement, distance from the sea, physical geography of coastal impact zone. Using a named example, evaluate the immediate and long-term responses to tropical storms • HICs and some NEEs may have resources and technology, such as satellites and specially equipped aircraft, to predict and monitor the occurrence of storms. They are also equipped to train the emergency services appropriately and to educate people about necessary precautions. Storm warnings can be issued to enable the population to evacuate or prepare themselves for the storm. People can prepare by storing food and water or boarding up their windows. • Immediate responses may include evacuation of people before storm arrives, rescue people cut off by flooding, set up temporary shelters, provide supplies of food, water, gas, electricity supplies, recover dead bodies to reduce disease risk, NGOs provision of aid workers, supplies, equipment. • • Long term responses may include repair of homes, rehousing programmes, repair of damaged infrastructure, improved forecasting techniques, improved flood defences, promotion of economic recovery, improved building regulations, changed planning rules to avoid most vulnerable areas.

• Understanding how different groups of people respond to tropical storms, including individuals, organisations, local governments, the national government and international aid organisations/foreign governments

• Individuals can construct makeshift flood defences to prevent their land from being flooded (eg sandbags). Local governments ensure that education is provided and messages are given to locals to warn residents about potential hazards such as flooding and contaminated drinking water supplies

• organisations identify hazard-prone areas at risk of flooding/environmental damage. • The national government ensures that relevant monitoring bodies produce the necessary information in forecasting the weather. It may mobilise military or emergency aid resources to prepare flood defences, evacuate people, respond to contamination, and protect crops and wildlife. • Knowledge and understanding of specific example of a tropical storm eg Haiyan. Immediate/emergency responses. Government evacuated over 1 million people-over 1200 evacuation centres. Many sought refuge in an • Many sought refuge in an indoor stadium in Tacloban but some died when it was flooded. The government sent essential equipment and medical supplies to some regions. Emergency aid supplies arrived three days later by plane once the airport was reopened. It was a week before power was restored in some regions and partially in others. Within two weeks, over one million food packs and 250,000 litres of water were distributed. $1.5 billion in foreign aid. A curfew was imposed two days after Typhoon Haiyan to reduce looting. • Longer term responses included rebuilding of roads, bridges and airport. Rice farming and fishing quickly re- established. Aid agencies helped to fund new fishing boats. Thousands of homes built away from flooded areas. More cyclone shelters. New storm surge warning system ‘Build Back Better’ -buildings upgraded with improved protection. Mangroves replanted. Plans to build new road dike.

• Assessment/evaluation of different types of response. Individual responses have a relatively small impact on reducing damage. People may be able to protect their own land or property but not much beyond that. National governments can have the biggest impact because they have the resources, capacity and authority to respond to economic, social and environmental effects on a large scale. Aid organisations may focus on social impacts (safety, food, shelter), but will often invest in longer term projects and solutions. • Effectiveness of responses may be determined by many factors, including available technology, infrastructure, communications, remoteness of area affected, degree of preparedness, monitoring systems, capacity of emergency services, education, building design. The distinction between HIC and NEE responses can be over-simplistic. Some poorer countries such as Bangladesh have early warning systems, tracking, cyclone shelters, coastal defences which have reduced death tolls considerably. How monitoring, prediction, protection and planning can reduce the effects of tropical storms • Predict

• Plan (this can be at a variety of different scales… individual, local and national!) • Protect

Monitoring and Prediction • The technology for monitoring tropical storms may sound old-fashioned — weather satellites and specially equipped planes. • The first time a plane flew into a hurricane on purpose was in 1943, near Galveston, Texas. Now, a group of pilots and scientists called the Hurricane Hunters regularly soar through storms that threaten the United States. • Aircraft from the U.S. Air Force and NOAA (National Oceanic and Atmospheric Administration – U.S. Government Agency) measure wind speeds, barometric air pressure, rainfall and snow. They also release sensors called dropsondes, which fall through the storm and send back data in real time to improve forecasting models. The dropsondes descend by parachute, sending two to four measurements per second by radio to aircraft nearby.

Video: Ride With Hurricane Hunters Into Irene's Eye • http://www.livescience.com/15789-ride-hurricane-hunters-irenes-eye.html • NASA has added unmanned aircraft, called drones, and are developing a new weather satellite that will soon peer through clouds to scan rainfall inside a hurricane, providing 3D views and data that feeds into weather models that run on supercomputers, help us to predict where storms are forming and where they are predicted to go.

• There are two levels of warning issued in the North Atlantic – Hurricane watch: Hurricane conditions possible – Hurricane Warning: Hurricane conditions are expected and people should take immediate action

Tracking Typhoon Haiyan

Answers to questions

1. Describe the characteristics of Typhoon Haiyan at 11pm on Thursday 7th November – Max wind speeds 370km/h – Category 5 – Just under 500km wide – Off the east coast of the Philippines travelling in a west (WNS) direction 2. Describe the direction of the predicted track of the typhoon – Predicted to travel WNW, then as it hits the coast of Vietnam it changes to a NW direction 3. How many hours was the typhoon expected to take to cross the Philippines? – At least 21 hours 4. Where was the typhoon expected to make landfall after the Philippines? – Vietnam 5. Why does the area showing the predicted track become wider over time? – The future track of the storm is uncertain…the further into the future the harder it is to predict! Planning – National/local scale 1. Control urban development in high risk areas. However this is unrealistic in many cases…can you think why?

• Tens of millions of people live in and work in high risk coastal areas already because of the economic benefits of living coastal areas. For example, many people rely on – fishing to make a living (e.g. Phillipines struck by Typhoon Haiyan 2013) – tourism to make a living (e.g. Miami Beach, Florida, struck by a hurricane in 1992)

• In some countries space is already limited and with rising population it is unrealistic to expect people to avoid building in coastal areas (e.g. Bangladesh) 2. Have effective communication & education to raise community awareness about how to plan and prepare for the potential risk of tropical storms

USA there is a National Hurricane Preparedness Week. On each day of that week, there is a particular focus that people are educated about and encouraged to prepare for https://www.weather.gov/wrn/hurricane-preparedness

3. Good warning systems in place to enable timely and safe evacuation

In Bangladesh, warnings are issued… • In several languages • By Radio, TV and Social Media • By Bike in some remote rural (countryside) areas

As a result of this and other improvements in the 3 Ps, the number of deaths has decreased 100 fold over the past 40 years…

1970 = 500,000 deaths 2007 = less than 5,000 deaths 4. evacuation plans in place which are reviewed and updated regularly.

What sort of things do local officials have to think about when creating an evacuation plan? …perhaps think about our fire drill evacuation to help you start this! Planning for a Tropical Storm: Individual Scale

• Listen to the Radio for tropical storm progress report, • Check your disaster supply kit to ensure it is up to date, • Fuel your automobile. Be ready to drive 20 to 50 miles (35 to 80 km) inland to locate a safe place, • Bring in outdoor objects such as lawn furniture, toys, and garden tools, • Anchor outside objects that cannot be brought inside, • Secure buildings by closing and boarding up windows, • Remove outside antennas, • Turn refrigerator and freezer to coldest settings. Open only when absolutely necessary and close quickly. Freeze as much water as you can. This will help keep your refrigerator cold if the power is out for several days, • Store drinking water in jugs and bottles. You will need at least 1 gallon daily per person for up to seven days, • Moor boat securely or move it to a designated safe place. Use rope or chain to secure boat to trailer and use tie-downs to anchor trailer to the ground, • Review evacuation plan, • Collect essential medicines into one place so you can quickly grab them should you need to evacuate, and • Get extra cash. With the possibility of no electricity, ATM's and credit card purchases will not work.

TASK: Create a mnemonic to help you to remember the above planning procedures You need to use the first letter (shown in red) of each bullet point to create your mnemonic, but they can be used in any order. How could you protect people from the following hazards of a tropical cyclone

• Windows are usually broken by the strong winds, the broken glass posses a hazard • Due to a lot of rainfall, drains are unable to cope with the amount of water and therefore flood • Storm surges damage and destroy buildings along the coast line • Peoples homes that are damaged have no where to go for shelter • Due to flooding cars are unable to be used to rescue people or deliver supplies • Due to lots of rainfall rivers overflow and burst their banks

Protection in Cyclone Shelters

• Bangladesh has built over 2000 of these shelters as the country is a very low lying country with a very dense population where storm surges and flooding from cyclones can affect a massive proportion of the population

• Task: Use the Mix and match sheet provided to annotate your picture of the storm shelter Heads Tails

Shutters over windows ……which can be closed to protect the people inside from broken debris which could easily smash glass windows

Constructed of strong concrete Which will be sturdy in strong winds and wont be easily damaged by flying debris

Built on stilts and on raised so the building is raised above flood waters which could rise ground as a result of the heavy rain and storm surges

Stairs to take people into the ……as lifts might not work if strong winds damaged the building electricity supply

The shelter can be used as a …so people have somewhere safe to go if other buildings community centre, school or have been destroyed in the area medical centre Other Protection methods

1. Windows, doors and roofs are reinforced to strengthen buildings to protect against strong winds, travelling above 74 mph, which could easily blow doors off their hinges, tiles off the roof and blow objects around that could smash into windows 2. Storm drains are constructed in urban areas to help protect against the heavy rainfall and storm surges that could easily lead to flooding of roads as well as people’s homes and businesses 3. Sea walls are built along the coast to protect important buildings and roads from large waves and storm surges caused by the strong winds and very low air pressure 4. Levees are constructed either side of rivers to protect against the potential flooding of roads and people’s homes and businesses as a result of the heavy rainfall and low air pressure causing raised river levels and storm surges up river mouths Key Idea

The UK is affected by a number of weather hazards.

What you should know

• An overview of types of weather hazard experienced in the UK Weather & Climate: what's the difference?

Weather = The day to day conditions of the atmosphere. Climate = The average weather conditions expected, calculated using 30 years of past weather data. The UK has what we call a temperate climate, meaning: • Temperatures in the UK are normally relatively moderate (not extreme), rather than being extremely hot or cold. • Rainfall in the UK is normally relatively moderate (not extreme), rather than being extremely wet or dry • The changes between summer and winter are also usually relatively moderate, so our seasons aren’t massively different. Even though we have a relatively moderate climate, we still experience our fair share of: • Weather Hazards and

• Extreme Weather Events (when a weather event is significantly different from the average or usual weather pattern. This may take place over one day or a period of time).

Videos Clips Click on the hyperlink, then scroll down to see a variety of video clips from recent years • http://www.coolgeography.co.uk/9/Risky_Earth/BritainHazar ds/Britains_hazards.htm

Types of weather hazard in the UK August 2003 Drought and heatwave The UK experienced heatwave conditions lasting 10 days and resulting in 2,000 deaths. During this heatwave, on August 10th, a record maximum temperature of 38.5 °C was recorded in Kent, a record high which still stands today.

Jan 2005 Thunderstorms and heavy rainfall leading to flooding Exceptionally heavy rainfall caused devastating floods to many areas, especially in the north of England. In Carlisle, Cumbria heavy rainfall started on the 6th January, it lasted 36 hours and during this time 200mm of rainfall fell, this was the equivalent of 4 months’ rain

Types of weather hazard in the UK July 2006 The warmest month on record over much of the UK

May-July 2007 Prolonged rainfall

June. was one of the wettest months on record in Britain as average rainfall across the country was more than double the June average. Some areas received a month's worth of rainfall in just 24 hours. It was the UK's wettest May–July since records began in 1776 As a result flooding was widespread across the UK from mid-June to late July

2012 wettest summer on record in UK Prolonged rainfall leading to drought

Dec 2013 to Feb 2014 This was England’s wettest winter in 250 years which led to severe flooding across southern England, as the River Thames burst its banks and vast areas of the Somerset Levels to become under water. Summers of 2013 -2014 were amongst the warmest

and sunniest in the UK in recent years • Sept 2016 • Conditions varied hugely across the country, with a high of 34.4C in Gravesend making Tuesday 13th September the hottest September day since 1911. • During the evening on the same date, a number of residents in Sheffield filmed what appeared to be a tornado on the outskirts of the city Heavy snow and extreme cold

November 2010 • A long period of heavy snow and very cold weather across the UK

• Which words do you think are important in the above definition to help us appreciate that this was an extreme weather event rather than just a ‘cold spell’?

Strong winds

Storm Doris feb 2017 • Storm Doris was named on the 21 February as yellow and amber warnings for wind, snow and rain were issued by the Met Office. • Overnight and into the morning of the 23 February, Storm Doris underwent explosive cyclogenesis labelling it a weather bomb. The centre of the storm moved rapidly through Northern Ireland in the early hours, across northern England and out into the North Sea by the early afternoon • Woman killed in wolverhampton

‘The weather of the UK is becoming more extreme.

• Have examples of extreme weather events throughout history in the UK i.e. Great Storm of 17038,000-15,000 lives lost • Also experienced heatwaves in past 1906 Aug to Sept temps of 32c across UK normally would be 15c to 16c • Extreme weather events are becoming more frequent 5/10 most extreme north Atlantic winters in last 10 years • Increasing number of droughts across the UK 2012 march drought but towards end of year intense periods of rainfall second wettest year since records began

• Extreme weather events are lasting for longer periods • Impacts are becoming more sever

Key Idea

Extreme weather events in the UK have impacts on human activity

What you should know

An example of a recent extreme weather event in the UK to illustrate: • causes • social, economic and environmental impacts • how management strategies can reduce risk. • Evidence that weather is becoming more extreme in the UK. The BIG Freeze, 2010 Extreme Weather Event in the UK: The BIG Freeze, 2010 • Extreme Weather is when a weather event is significantly different from the average or usual weather pattern. This may take place over one day or a period of time.

• What was the Big Freeze? A long period of heavy snow and very cold weather across the UK.

• When? Between 25th Nov – 26th Dec, 2010, there were 2 long periods of very cold weather with a brief thaw in- between, resulting in the coldest December in 100 years. • Why? (CAUSE): …but, unusually, at this time, high air pressure over the North Pole was pushing cold air from the Arctic, over NORTHERN EUROPE and SIBERIA, towards the UK.

Nov-Dec, 2010 winds

Usually, our winds come from the west and South west, across the Atlantic, which has a warming effect on the UK…

Copy the sub heading, stick your map in your book and annotate it to explain what caused the big freeze Social Several people died from hyperthermia or accidents due to losing control on icy roads.

Social and economic

• 7000 schools closed meaning parents had to take time off work • Motorways were shut (part of the M8 was closed for 2 days). Drivers were trapped in their cars for 15 hours. On 20 December the AA reported its busiest-ever day because of car breakdowns • Airports closed, including Gatwick and Heathrow, and many trains were cancelled • Lots of water pipes froze and burst resulting in 40,000 homes and businesses across northern Ireland were without water for over a week. Economic Shop sales were down at Christmas as shoppers were put off by the weather Environmental and economic • Snow covered almost all of the UK, over 50cm in hilly locations • Frost damaged crops, especially sugar beet. • Use of gas and electricity more than doubled, increasing CO2 emissions

Management strategies used to reduce the risk from weather hazards

PREDICTION: Warning systems gave The met office warned about the cold people time to prepare for the extreme weatThe met office warned about weather the cold weather at the start of November her at the start of November

PROTECTION: Individuals and local Councils stocked up on authorities prepared for the extreme weather before it happened gritters and salt supplies to keep roads safe and open, although there were some shortages as time went one

PLANNING: Emergency services and They made plans to close schools local councils planned how to deal with when it would be too dangerous extreme weather events in advance for people to get there