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Click on today's infra-red satellite images below for full size version (images: Nottingham & Dundee University)
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We begin today's report with a feature on the weather currently affecting the British Isles. The weather is in lively mood! As weather charts for north-west Europe and adjacent parts of the North Atlantic Ocean show, deep depressions are moving north-eastwards from the open Atlantic across northern Scotland, Orkney, Shetland and the Faroes towards Scandinavia. At 1200 UTC, the centre of a depression with a central pressure of 968 mb was located at 58°N 15°W, with wind speeds of 22 m/s (Force 9) on its southern flanks. These were sustained winds (from the west), not short-lived gusts, which would have been considerably stronger than 22 m/s.
By 1800 UTC, the centre of the depression had reached north-west Scotland, with sustained winds of 20 m/s over Northern Ireland and the western isles of Scotland. Gusts in excess of 30 m/s have been recorded this evening. The depression is, however, expected to lose most of its vigour by lunch-time on 8 February, when it is expected to be over southern Norway. Indeed, it had begun to fill by 1800 UTC today. Another vigorous depression (977 mb), which was centred at 51°N 39°W at 1200 UTC today, is expected to reach 60°N 20°W by 1200 UTC on 8 February. Its fronts are expected to sweep across the British Isles after midnight tonight, reaching eastern England by 1200 UTC on the 8th.
In contrast to the weather over the British Isles, the weather over Iberia has been pleasant, with a ridge of high pressure from a High of 1040 mb off southern Portugal extending to south-west France. At Lisbon Airport today, the pressure reached 1037 mb, winds were very light and the temperature reached 16°C. At Malaga Airport, southern Spain, the pressure reached 1034 mb, the temperature reached 19°C and winds were, as at Lisbon, from the west-north-west, but somewhat stronger (10 m/s). The weather was misty at Barcelona Airport (Why was this? Can anyone explain?). At Madrid Barajas Airport, the temperature fell to -1°C at 0700 UTC today. It can be cold on the Spanish plateau at this time of year.
Elsewhere in Europe: the weather was quite cold in Cyprus this morning (a temperature of only 4.5°C reported by the American School at 0600 UTC); and it was unsettled in Geneva, where there was light rain this morning.
At Edmonton, Canada, temperatures fell quite a way below freezing last night, with a minimum temperature of -14.0°C recorded by James Gibbons School and -16°C at Edmonton International Airport. In Scandinavia, where temperatures can be quite low at this time of year, winds from a southerly point brought warm air and temperatures above freezing.
Once again, smoke was reported hour after hour at Bombay's Santa Cruz Airport, indeed every hour from 1500 UTC (2030 local time) on 6 February to 0900 UTC (1430 local time) today. For much of the time, the wind was calm. I ask again if the cause was pollution trapped under a night-time inversion? Is there an industrial area close to the airport?
Temperatures were again in the twenties and thirties Celsius at the MetLink schools in Oman, Ethiopia and Uganda, and at the school on Ascension. They were, too, at the schools in southern Africa, but conditions were rather cloudy there (as they were, in fact, over Ascension). Today's CTOT, DTOT and ETOT Meteosat images show that the Intertropical Convergence Zone (ITCZ) was active over a wide area of southern Africa today, with the greatest activity just south of the equator at about 20°E. A depression centred over Kwazulu-Natal gave Hilton College humid, overcast conditions.
Finally, we visit Australia, where the temperature has not been as high today as it was on some days last week. With pressure high to the west of Tasmania (1026 mb) and between New South Wales and New Zealand (1033 mb), with a weak trough of low pressure extending south-eastwards from a Low over north-west Australia, winds have been quite light (mainly from the south or south-south-west) in the Melbourne area. The temperature reached 24°C at Melbourne Airport at 5 pm (local time) and 24.2°C at Trinity College. At Southmoor Primary School, a higher maximum temperature was recorded.
How did the weekend weather affect your leisure activities? Please tell us. Perhaps your students might like to let us know.
In the Reading area today, there was another spectacular sunrise, every bit as spectacular as the one seen last Thursday (see the report for primary schools for 3 February). Fiery red, delicate pink, bright orange, pale yellow: the show included them all. Like last Thursday, though, the sunrise foretold poor weather. For much of the day, as the weather report from Reading's Collier Primary School and reports from other MetLink schools indicate, the weather was dull, overcast, wet and windy. Not until the late afternoon did the clouds part, to give a clear, starry evening.
The rain fell from a cloud called Nimbostratus, which is a thick, dark layer of cloud. Stratus is the name given to sheets/layers of cloud. Nimbus is the name given to clouds that rain. So, Nimbostratus is a sheet/layer of cloud that produces rain (or snow).
Heaped up, towering clouds that produce rain (or hail or snow) are called Cumulonimbus, the first part of the word coming from Cumulus, meaning a heap. Heaped up clouds that look like cauliflowers or lumps of cotton wool are simply called Cumulus if rain is not falling from them.
The highest clouds, which appear wispy and hair-like, are so high (typically above about 8 km altitude) that they are made of ice crystals. They are called Cirrus clouds.
Combinations of cloud names are used, so, for example, we have sheets/layers of ice clouds which we call Cirrostratus. Clouds at medium levels have the prefix Alto-, from which we get Altostratus and, if the cloud is broken, Altocumulus. There are ten basic cloud types, the others being Cirrocumulus, Stratus and Stratocumulus.
Before a belt of rain like today's arrives, you typically see a sheet of ice cloud (Cirrostratus) followed first by a sheet of Altostratus then Nimbostratus.
What will the weather be like tomorrow? Well, the weather is in boisterous mood at the moment over the north-east Atlantic and north-west Europe. Gales are forecast, severe in places. There's more rain to come. What clouds will you see on 8 February? How windy will it be? From which direction will the wind blow?
In Oman, Ethiopia and other parts of the MetLink world, they don't see too many clouds at this time of year. That was true today, but this is the rainy season over southern Africa, so it was not surprising to find that lots of cumulus and cumulonimbus clouds occurred there and that rain fell at the MetLink schools in Zambia and Zimbabwe. At Hilton College, South Africa, a depression gave cloudy, humid conditions. The clouds over southern Africa can clearly be seen on today's satellite images. These Meteosat images show what the clouds would have looked like to someone in the satellite. They are called 'Visible images', as distinct from 'Infra-red images', which show temperatures.
On a visible image, you see clouds as though you were looking with your own eyes but in black and white. Clouds appear white. Snow appears white. Deserts are light-coloured. The sea appears dark, except where the sun is reflected from it.
On an infra-red image, white indicates cold, black indicates warm. Thus, on an infra-red image, the highest clouds are the whitest, because they are so cold (maybe -60°C or even colder). By day, desert areas appear black, because they are so warm (sand and bare rock get quite hot when the sun shines strongly).
Today was considerably cooler at our schools in south-east Australia than it was on some days last week. Indeed, the maximum temperature was 'only' 24°C at Melbourne Airport and Trinity College today. The weather is mild in the United Kingdom at the moment, with temperatures up to 13° or 14°C in some places, but we don't enjoy temperatures as high as the mid-twenties Celsius as early in the year as February.
In Spain and Portugal today, the weather has been quite settled. The dominant influence has been an anticyclone south-west of Portugal, giving light winds and pleasant temperatures (15.9°C at our MetLink school in Tarragona). At the other end of the Mediterranean, in Cyprus, there has been a lot of sunshine, but temperatures have not been very high. At the American School in Cyprus at 0600 UTC today, the temperature was only 4.5°C. Back in Spain, at Madrid, high on the Spanish Plateau, the temperature fell to -1°C early today. Inland Spain can be quite cold at this time of year.
In Scandinavia, temperatures were well above average, with a maximum of +5.7°C reported at Bor School, Sweden, and a maximum of +3.1°C at Vörå, Finland. In Alberta, too, temperatures are not especially low, but they did fall to -14°C at our school in Edmonton, James Gibbons School.
How different are the temperatures of the past week or so from normal for this time of year? To find out, why not visit the Royal Meteorological Society's Climate on the Web page?
How did the weekend weather affect your leisure activities? Please tell us. Perhaps your students might like to let us know.
