Weather images

Figure 1.

After the extreme cold of December, there was a marked change in the weather pattern in January as a mobile westerly type developed. However, the very cold air did not give way without a fight, and the 7th was extremely cold over northern and central regions with persistent frost and locally heavy snow. Across southern Britain, though, many places had their highest temperature for seven weeks, albeit accompanied by spells of heavy rain. The complex nature of the frontal systems on this date is well shown by the infra-red (Channel 4) satellite picture for 1357 utc on 7 January 2011. (Satellite image courtesy of University of Dundee.)

Figure 2.

A strong airflow of very mild air from the North Atlantic was well-established across the British Isles in mid-January 2011 (even though some of the earlier days had not been all that mild, the mean temperature for the first half of the month over southern Britain was 5 degC higher than it was for the same period in January 2010). This radar image shows the soaking much of the country (except the southeast) was experiencing at 0300 utc on 15 January 2011. The darkest images suggest a rainfall rate of close to 5mmh–1. (Radar image courtesy

Figure 3.

Despite a fairly dry last fortnight of the month, it was one of the wettest Januaries of recent years in southern Britain and this radar image picks out a particularly wet morning, showing the rain from a wave on a cold front at 0800 utc on 17 January 2011: the heaviest rain is indicated at about 5mmh–1. This was also a very showery day over northwest Scotland – and another rain area crossed the south at night before an anticyclone developed over the country and dominated the British weather for the rest of the month. (Radar image courtesy

Figure 4.

This near-infrared (Channel 2) satellite image for 1343 utc on 18 January 2011 shows the cloud from the last rain area clearing away to the southeast of England, leaving fairly sunny skies across much of the country. The sunshine was especially welcome in the southeast because, although December had been a month of record sunshine for areas of northern and western Britain, it was exceptionally dull here – for many, this was only the second sunny day in eight weeks (and sunshine remained at a premium thereafter this month). (Satellite image courtesy of University of Dundee.)