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Click on today's infra-red satellite images below for full size version (source: Nottingham University)
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At Southmoor Primary School at 0030 UTC (1130 local time), there was a northerly wind of 24 kph and a temperature of 35.2°C. In the words of the school, it was a "scorcher of a day". An anticyclone (1027 mb) was centred between the North Island of New Zealand and south-eastern Australia, and the northerly wind was consistent with this (as winds blow anticlockwise around anticyclones in the southern hemisphere). This is the time of year when northerly winds (i.e. winds from the north) are hot in south-eastern Australia. They convey hot air from the interior of Australia. The midday sun is still high in the sky in Australia in February, this being a summer month in the southern hemisphere.
The JMA/GMS5 satellite image for 0600 UTC shows a line of cloud running across Tasmania and northern parts of the Great Australian Bight. The weather charts from the Australian Bureau of Meteorology showed this to be an eastward-moving cold front which reached Melbourne about 1300 UTC. Like yesterday, there was a lot of cloud over central and north-western Australia, and there was also a lot over South Australia. This was mainly high cloud, much of it associated with a large area of low pressure (998 mb) centred near Port Hedland, Western Australia. The monsoon was active over the northernmost parts of Australia.
At the American School, Bombay, at 1000 UTC (1530 local time), there was a temperature of 27°C, a humidity of 51%, a south-westerly breeze and hardly any cloud. This sounds very pleasant. At the MetLink school in Muscat, Oman, we had a surprise today. It wasn't sunny! The temperature was only 20°C at 0800 UTC and the cloud cover was 8 eighths. The school's weather reporters said that the weather was overcast and mentioned that they thought "the first rain for months" might fall.
How often does rain fall in Oman at this time of year or, indeed, any time of year? To find websites that might help answer this question, click here.
Like yesterday, the sequence of satellite images during the morning and afternoon shows that cumulus and cumulonimbus activity over the southern half of Africa increased during daylight hours. Small cumulus clouds look like balls of cotton wool . Bigger ones look like cauliflowers. Cumulonimbus clouds look like cauliflowers with anvil tops, and these clouds give showers of rain, hail or snow. They increase during the day because the ground is heated by the sun during the day, creating buoyant bubbles. The ground is heated strongly in Zambia and Zimbabwe at his time of year, when the midday sun is almost overhead. In these countries, this is the rainy season. However, rainfall amounts reported today by the MetLink schools in Zambia and Zimbabwe were small.
Our school in Zambia reported that the weather was "cool", but a maximum temperature of 25°C and a minimum of 18°C seems rather comfortable to folk from northern Europe just now! In southern England at this time of the year, a temperature of 2 or 3°C is quite low, but for central Canada in February it's quite high. Warm and cold are really rather relative terms!
The depression that has brought cloud and rain to Kwazulu-Natal, Transvaal and other parts of South Africa these past few days was still active today, as the weather report from Hilton College shows. This weather system has caused serious flooding in eastern parts of South Africa (see school news items on the MetLink website).
At the MetLink school in Kampala, Uganda, which lies near the northern edge of the cumulus-type activity, there was a rainy morning. Farther north, at Addis Ababa, Ethiopia, it was sunny and dry. At Ascension Island, in contrast, there was hardly a breath of wind and it was, in the words of the school, "hot and humid". The temperature was 26°C at 1300 UTC and a rainfall amount of 40 mm was measured.
At the American School, Cyprus, this morning, the weather was quite cold (temperature only 7°C at 0600 UTC), but the sun was shining. Pressure was still high (1031 mb) over Turkey. Pressure was still high, too, 1036 mb, to the west of southern Portugal and over Spain. At the Gabriel Pereira School at 1030 UTC, however, the weather was foggy and dull. At Tarragona, in contrast, Vidal reported no cloud, a very light north-westerly wind and a temperature of 16°C. The dominant weather influence at Malta today was an area of low pressure (1008 mb centred over southern Italy), and satellite images show that there was a lot of cloud associated with this weather system. The Achille Ferris Primary School reported a north-westerly wind of 44 kph, 5/8 of cloud and occasional showers. The weather was much better at Geneva today than yesterday, a ridge of high pressure from the High over Iberia bringing clear skies. At the MetLink schools in Finland and Sweden, temperatures were still above average for the time of year. At Vörå, there is now no snow, which is unusual for February in central Finland.
The day began wet and windy in many parts of the British Isles today. At 0000 UTC, a depression (975 mb) was centred west of Scotland at 58°N 15°W. By 1200 UTC, this Low had moved rapidly north-eastwards to 65°N 3°E and deepened to 968 mb. Warm, cold and occluded fronts associated with this Low moved quickly eastwards across the British Isles, giving heavy rain and strong winds overnight and in the morning. By early afternoon, clouds associated with this depression had reached much of Norway and Sweden. By evening, most parts of southern Britain were almost cloudfree. To the west and north-west of the British Isles, as satellite images show, there was a lot of shower activity. Notice on the satellite images that the cumulonimbus cloud systems that produced the showers were arranged in cells which were roughly hexagonal, i.e. there were hexagonal groups of clouds (where ascent of air was predominant) with clear skies inside them (where air was descending). The 0555 UTC satellite images from Dundee and the corresponding Meteosat D2 images show this particularly clearly.
STUDY IDEA: Next time there is a showery day, notice how much temperature varies as cumulonimbus clouds move across your locality. These clouds have warm indraughts and cold downdraughts, and the temperature difference from one to the other can be several degrees Celsius. Notice also how much the wind speed and direction vary as cumulonimbus clouds pass over.
At the James Gibbons School in Edmonton, the temperature was -17°C at 1600 UTC (0900 local time), two degrees lower than at the same time yesterday. The wind was light northerly, snow fell overnight and ice crystals were in the air at the time of the observation.
How much does wind direction determine temperature in Alberta?
At Southmoor Primary School at 0030 UTC (1130 local time), there was a northerly wind of 24 kph and a temperature of 35.2°C. In the words of the school, it was a "scorcher of a day". An anticyclone (1027 mb) was centred between the North Island of New Zealand and south-eastern Australia, and the northerly wind was consistent with this (as winds blow anticlockwise around anticyclones in the southern hemisphere). The JMA/GMS5 satellite image for 0600 UTC shows a line of cloud running across Tasmania and northern parts of the Great Australian Bight to the Nullarbor Plain. The weather charts from the Australian Bureau of Meteorology showed this to be an eastward-moving cold front which reached Melbourne about 1300 UTC. Like yesterday, there was a lot of cloud over central and north-western Australia, and there was also a lot over South Australia. This was mainly high cloud, much of it associated with a large area of low pressure (998 mb) centred near Port Hedland, Western Australia. The monsoon was active over the Cape York Peninsula, the Gulf of Carpentaria and Arnhem Land.
At the American School, Bombay, at 1000 UTC (1530 local time), there was a temperature of 27°C, a humidity of 51%, a south-westerly breeze and hardly any cloud. This sounds very pleasant. At the MetLink school in Muscat, Oman, we had a surprise today. It wasn't sunny. The temperature was only 20°C at 0800 UTC and the sky was overcast. The school's weather reporters thought "the first rain for months" might fall.
How often does rain fall in Oman at this time of year or, indeed, any time of year? To find websites that might help answer this question, click here.
Like yesterday, the sequence of satellite images from 0300 to 1500 UTC shows that cumulus and cumulonimbus activity over the southern half of Africa increased during daylight hours. This is the rainy season in this part of the world. At the MetLink schools in Zambia and Zimbabwe, however, very little rain fell during the 24 hours prior to the schools' observation times, as the rainfall amounts reported by these schools show.
Our school in Zambia reported that the weather was "cool", but a maximum temperature of 25°C and a minimum of 18°C seems rather comfortable to folk from northern Europe just now! In southern England at this time of the year, a temperature of 2 or 3°C is quite low, but for central Canada in February it's quite high. Warm and cold are really rather relative terms!
The depression that has brought cloud and rain to Kwazulu-Natal, Transvaal and other parts of South Africa these past few days was still active today, as the weather report from Hilton College shows. This weather system has caused serious flooding (see school news items on the MetLink website). At the MetLink school in Kampala, Uganda, which lies near the northern edge of the cumulus-type activity, there was a rainy morning.
Farther north, at Addis Ababa, Ethiopia, it was sunny and dry. At Ascension Island, in contrast, there was hardly a breath of wind and it was, in the words of the school, "hot and humid". The temperature was 26°C at 1300 UTC and a rainfall amount of 40 mm was measured. Satellite images indicate that the ITCZ was quite active over the Atlantic Ocean today, just south of the equator.
Over North Africa, as CTOT, DTOT and ETOT Meteosat images show, the wavy band of high cloud that was conspicuous yesterday was still to be seen but nowhere near as well defined as yesterday.
The 1200 and 1500 UTC DTOT images suggest that a sea-breeze system existed over western Namibia and south-western parts of South Africa at this time.
At the American School, Cyprus, this morning, the weather was quite cold (temperature only 7°C at 0600 UTC), but the sun was shining. Pressure was still high (1031 mb) over Turkey. Pressure was still high, too, 1036 mb, to the west of southern Portugal and over Spain. At the Gabriel Pereira School at 1030 UTC, however, the weather was foggy and dull. At Tarragona, in contrast, Vidal reported no cloud, a very light north-westerly wind and a temperature of 16°C. The dominant weather influence at Malta today was an area of low pressure (1008 mb centred over southern Italy), and satellite images show that there was a lot of cloud associated with this weather system. The Achille Ferris School reported a north-westerly wind of 44 kph, 5/8 of cloud and occasional showers. The weather was much better at Geneva today than yesterday, a ridge of high pressure from the High over Iberia bringing clear skies. At the MetLink schools in Finland and Sweden, temperatures were still above average for the time of year.
The day began wet and windy in many parts of the British Isles today. At 0000 UTC, a depression (975 mb) was centred west of Scotland at 58°N 15°W. By 1200 UTC, this Low had moved rapidly north-eastwards to 65°N 3°E and deepened to 968 mb. Warm, cold and occluded fronts associated with this Low moved quickly eastwards across the British Isles, giving heavy rain and strong winds overnight and in the morning. By early afternoon, frontal clouds had reached much of Norway and Sweden. By evening, most parts of southern Britain were almost cloudfree. To the west and north-west of the British Isles, as satellite images show, there was a lot of shower activity. Notice on the satellite images that the cumulonimbus systems that produced the showers were arranged in cells which were roughly hexagonal, i.e. there were hexagonal groups of clouds, where ascent of air was predominant, with clear skies inside them, where air was descending. The 0555 UTC satellite images from Dundee and the corresponding Meteosat D2 images show this particularly clearly.
Next time there is a showery day, notice how much temperature varies as cumulonimbus clouds move across your locality. These clouds have warm indraughts and cold downdraughts, and the temperature difference from one to the other can be several degrees Celsius.
At the James Gibbons School in Edmonton, the temperature was -17°C at 1600 UTC (0900 local time), two degrees lower than at the same time yesterday. The wind was light northerly, snow fell overnight and ice crystals were in the air at the time of the observation.
How much does wind direction determine temperature in Alberta?
