Weather hazards in the UK

Any one valid method. Accept 'weather forecasts'.

Do not accept 'towards the west' or 'from the west'.

Accept 'polar continental air'.

Indicative content (not a checklist; credit other valid points): climate change is raising average temperatures, so heatwaves are hotter and more frequent and records are broken (e.g. 40.3 °C in 2022); warmer air can hold more water vapour (about 7% more for each 1 °C), so when it rains, rainfall can be heavier, increasing flooding; warmer seas provide more energy and moisture to storms and depressions; some scientists suggest changes to the jet stream may make it wavier or slower, so weather patterns get 'stuck', giving long spells of rain or long heatwaves and droughts; natural variations (e.g. in the North Atlantic) also cause unusual years; better instruments, more weather stations and more media coverage may also make extreme events seem more common.

Indicative content (not a checklist; credit other valid points): Somerset Levels floods (winter 2013-14): a series of depressions from the Atlantic, driven by a strong jet stream, gave the wettest winter on record; the ground became saturated, so rain ran straight into rivers; high tides and storm surges stopped the rivers Parrett and Tone draining to the sea; the Levels are flat and low-lying, some land close to sea level, so water could not drain away; the rivers had not been dredged for about 20 years, so silt reduced the amount of water they could carry. Storm Desmond (Cumbria, December 2015): a deep depression brought a long stream of warm, moist air from the subtropics on strong south-westerly winds; the air was forced to rise over the Cumbrian mountains, giving heavy relief rainfall (a record 341.4 mm in 24 hours at Honister Pass); the ground was already saturated after a wet November, and steep slopes sent water quickly into rivers such as the Eden, Kent and Derwent. 'Beast from the East' (2018): a sudden warming high above the Arctic disrupted the usual circulation; high pressure over Scandinavia drove very cold easterly winds from Russia and Siberia; the air picked up moisture over the North Sea and dropped it as snow; Storm Emma moving up from the south met the cold air, giving heavy snow and blizzards in the south-west and Wales. July 2022 heatwave: high pressure brought clear skies and drew a plume of very hot air north from North Africa and Spain; dry ground heated quickly; climate change made such extreme temperatures much more likely. Credit any appropriate named example.