Tuesday night could be the coldest so far this year with temperatures expected to drop as low as minus 15°C in the UK, the Met Office has warned. This would break the current record of minus 10.4°C recorded in the Scottish Highlands earlier this year. The coldest areas on Tuesday are likely to be in sheltered Scottish glens, particularly where there is fresh snow cover. The UK's National Grid has warned of a tight power supply due to a shortage of electricity caused by the cold snap. The shortfall of up to 980 megawatts is larger than the current contingency requirement, and the National Grid has requested coal-fired plants to stand by, with three more coal units preparing to generate power on Tuesday. Wind generation has slumped to provide only 13 per cent of the nation's power capacity. <a href="https://www.thenationalnews.com/world/uk-news/2023/01/05/met-office-2022-was-uks-warmest-year-on-record/" target="_blank">The Met Office</a> and the UK's Health Security Agency have issued warnings for snow and ice in large parts of the country this week. The arctic air sweeping across the UK is due to a “highly amplified” jet stream, mixed with an area of lower pressure over the mid-North Atlantic, which is pushing air up into northern areas and back down towards the UK. Yellow warnings have been issued across the UK and will remain in place in some areas until Friday. Another yellow warning is in place for much of northern and eastern Scotland and north-east England until 10am on Wednesday. South-west England and south Wales will be covered by a similar weather warning all day on Wednesday, with a few centimetres of snow expected to fall in those areas. The Met Office warnings for ice and some snow could lead to difficult travel conditions in some places. A band of rain moved southward through the course of Monday evening and early Tuesday, turning to snow on hills and lower levels in some areas. While most areas will get little or no accumulation of snow, 1cm to 2cm could settle in some spots, particularly over high ground and southern parts of the warning areas. Rain and snow are expected to turn light and patchy as southern England gradually clears on Tuesday. However, as skies clear overnight, ice is also likely to form on untreated surfaces. The Met Office urged people in affected areas to stay alert to changing weather and heed the advice of local authorities. It also advised taking necessary precautions, such as dressing warmly and driving safely on icy roads. The Met Office has issued some guidance for driving in the heavy snow and icy conditions.