November 18th-20th cold snap

A short but dramatic cold snap gripped the UK for a few days during mid-November bringing with it some quite widespread falls of snow to parts of the UK and some bitterly cold temperatures.

On the 18th November a developing low on the wave of an old front separating relatively warm, moist air to the south and colder, drier polar air to the north; brought a large area of rainfall across the UK throughout the day which edged slowly south-eastwards. To the north of the front across Scotland it was a fairly cold but mainly dry day with a few sleet and snow showers moving into Shetland, Orkney and the far Northeast of Scotland. It was though a thoroughly wet day for central parts of England and Wales with as much as an inch falling under the slow moving front. During the afternoon the much colder polar air to the north began to undercut the warm air lying over central areas - turning the rain readily to snow, catching forecasters and the general public alike by surprise.

By late afternoon moderate snow was falling across much of the higher parts of Northern, central England and Wales, even in Northern Ireland – as much as 8cm (3 inches) were reported in Hathersage, Derbyshire with accumulations of snow quite widespread in upland areas. Further South across the Midlands and East Anglia the rain even here down to low levels by dusk was turning to snow – reports came in of snow from Birmingham, Leicester and Cambridge - even settling with the consequences of turning the roads quite icy in places. There was also a report of snow on the ground from a recently retired certain Mr. M Fish in Peterborough (!)

IN PICTURES : The UK’s first snow of Winter 2004

http://news.bbc.co.uk/1/hi/in_pictures/4026257.stm

The 19th was then a cold day for the whole of the UK, and there were some heavy snow showers for the Northern Isles and parts of N and E Scotland giving some accumulations here of up to around 5cms. Elsewhere it was dry and cold with maxima generally only 4C – 6C with parts of the North and East struggling to get much above freezing. As night fell so did the temperatures and quite dramatically too, to as low as -8C at Tulloch Bridge. During the afternoon though a warm front was moving towards Ireland heralding a change to much milder weather.

As the precipitation from the warm front moved North-eastwards, it's progress very slow on the 20th, the leading edge moved into the cold air over the UK and began to fall as sleet or snow. Higher parts of the West of England and Wales had slight accumulations of snow with the Cotswolds and Chilterns turning white throughout the day as the snow continued to fall. Again even at low levels sleet was reported as far south as Surrey making the racing at Lingfield Park quite a wintry affair and bringing a thoroughly cold day to most inland parts. In fact areas in the band of sleet and snow had temperatures remaining at or below 2C for much of the day. In the far N of Scotland it remained dry and cold with Loch Glascarnoch barely making -3C during the day - and the very cold air persisted well into the night allowing temperatures to fall to a bitterly cold -13.2C at Kinbrace, Sutherland, the coldest temperature reported this year.

Low midday temperatures on the 20th:

Low minima on the 20th:

On Sunday, the precipitation turned to ‘freezing rain’ across Scotland and NE England. (a rather rare and very dangerous meteorological phenomena where rain falls into a sub 0C layer, remains liquid until it freezes immediately onto a freezing cold surface leaving a coating of rime ice). Accidents were reported on parts of the M6 and M8 for a time during the morning where the freezing rain was falling and as a consequence were closed.

Analysis for the period 18^th – 21^st November 2004

http://www.wetterzentrale.de/archive/2004/brack/bracka20041118.gif

http://www.wetterzentrale.de/archive/2004/brack/bracka20041119.gif

http://www.wetterzentrale.de/archive/2004/brack/bracka20041120.gif

http://www.wetterzentrale.de/archive/2004/brack/bracka20041121.gif

During Sunday afternoon the warm up continued and gathered pace from the SW of England with temperatures rising to 15C in Devon by the end of the day and to at least double figures for all but the far E of England and far NE of Scotland. All in all it was quite an interesting and surprising period of weather bringing the first widespread snowfall of the winter that disappeared just about as quickly as it had appeared the previous Thursday.