3.1.1.3 Weather Hazards - Weather Hazards in the UK Flashcards
Weather hazard:
a weather event that is extreme enough that it causes risk to lives or property
Extreme weather event:
weather events significantly different from normal weather patterns over a period of time
What weather hazards does the UK experience?
- Thunderstorms
- Prolonged rainfall
- Drought and extreme heat
- Heavy snow and extreme cold
- Strong wind
Impacts of prolonged rainfall:
- lot of rain over long periods of time can cause river flooding, when rivers and streams reach their capacity - they overflow causing damage to properties and infrastructure
- homes flooded - families evacuate
- crops + livestock lost
Example of prolonged rainfall in UK + impacts:
- 2009 Cumbrian Floods
- Cockermouth experience unprecedented rainfall causing many rivers to overflow and flood nearby towns
Weather conditions associated with thunderstorms:
- lightning + torrential downpour
- warm, moist air
- unstable atmosphere
- intense, torrential rainfall
Impacts of thunderstorms:
- lightning strikes can cause damage to property and be lethal if they hit someone
- intense, torrential rainfall which can result in flash flooding
- damage to wildlife habitats
Example of thunderstorms in UK + impacts:
- Summer 2014 - period of many intense thunderstorms
- a lightning strike took the roof off a house in Chemsford
Weather conditions associated with droughts + extreme heat:
- long periods of extreme heat
- 32 degrees C for at least 2 days
- prolonged period of low precipitation
Example of drought + extreme heat in UK:
- 2022 - hottest Summer in 140 years
- 40.3 degrees C highest temp recorded in UK
Impacts of 2022 extreme heat in UK:
- crop failure
- wildfires
- cattle failure
- weather reserves decreased
- 10-15% of crops lost according to farmers
Weather conditions of heavy snow + extreme cold:
- heavy snow
- sub-zero conditions
What is the frequency of heavy snow and extreme cold weather events in the UK?
- UK can experience long periods of extremely cold weather in winter
- less frequent in recent years
Example of heavy snow and extreme cold in the UK:
- December 2009 - January 2010
- Scotland temps fell to below -15 degrees C
- mean December temperature of -1 degrees
Impacts of extreme cold + heavy snow in UK in 2009-10:
sheet ice formed - 2 deaths from bus overturning
Impacts of heavy snow + extreme cold in the UK:
- cold temps risk to population esp. elderly
- disrupt travel + cause accidents —> road closures, trains and planes cancelled
- freezing water supplies
- hypothermia - cold related illnesses
Why may the UK experience strong winds?
- due to remnants of storms from other areas
- e.g. old hurricanes can travel cross Atlantic Ocean and hit UK as a weaker storms
Example of strong winds in UK + impacts:
- strong winds in October 2013
- winds brought down a tree crushing a car in London
Impacts of strong winds in UK:
- blow over trees
- disrupt power lines
- cause damage to houses
Why does the UK experience extreme weather?
- UK is the meeting point of several different types of weather from dif. directions
- explains why we experience varied weather from week to week and how we can occasionally be affected by extreme weather events
Why may extreme weather be becoming more frequent in the UK?
- more E in atmosphere - getting warmer
- atmosphere getting hotter causing more intense and frequent periods of hot weather
- the way atmospheric circulation affects moisture and pressure is changing due to climate change - led to altered precipitation patterns
- weather patterns in UK may be getting stuck due to changing climate
- experiencing prolonged weather events more frequently
- UK’s weather controlled y jet stream (fast flowing air currents) that moves west to east across the UK
- sometimes the jet stream can be blocked and become stuck which causes weather patterns to be stuck over the UK, until it moves again
- causes heavy, prolonged rainfall to fall or can cause high temps over many weeks
How might climate change cause an increase in extreme weather events?
- Extreme weather may be becoming more frequent due to changes in atmospheric circulation, caused by climate change
- The Arctic is currently warming at a rate of twice the global average
- A warming Arctic, may slow down the atmospheric circulation in the northern hemisphere mid-latitudes resulting in weather sticking for long periods of time
- This could explain the recent extreme weather such as heatwaves and floods experienced in the UK
