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Weathercam "image of the day" Kristiansund, Sweden
Student maps & analysis for 24 March, 2000 |
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Weathercam "image of the day" Kristiansund, Sweden
Student maps & analysis for 24 March, 2000 |
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Today, there was a deep near-stationary depression over the Atlantic Ocean north-west of Ireland. At 0000 UTC, its depth was 977 mb and its centre was at 59°N 22°W. By 1200 UTC, its depth had changed little (being now 976 mb) and its centre had moved little, to 58°N 20°W. The Low's cold front moved eastwards across the British Isles and Brittany during the day. It had reached north-west Spain by early afternoon.
As on previous days, pressure was low over northern Norway, but the depression filled somewhat today. Its central pressure was 985 mb at 0000 UTC and 992 mb at 1200 UTC. The occlusion and cold front of this depression were still evident as weak features over western Russia, and the cold front joined up with the warm front of the Atlantic Low. The warm front extended from Iceland across the Orkney Islands to northern Germany and southern Poland.
Today's radar images showed a line of showers over western Scotland, Wales and south-west England. The line was almost continuous at 0800 UTC but had become rather broken by mid-afternoon. This line marked the cold front of the Atlantic depression. Showers occurred almost everywhere in the British Isles today, as the reports from many of the British schools show.
There was high pressure over Spain today (1020 mb at 1200 UTC) but the day was again rather cloudy, after a sunny start. Pressure was high over the central Mediterranean, the Balkans and the Black Sea (1021 mb near Naples at 1200 UTC, 1020 mb over the eastern part of the Black Sea). Troughs of low pressure brought cloud and rain to many parts of Europe today, including most of Italy.
There was a broad north-westerly flow over Scandinavia, Estonia, Latvia, Lithuania and northern Poland. Winds blew from a southerly point over the British Isles - from the south-east over Scotland, south-south-west over Ireland, Wales and southern England. The winds were from the south-west over France and rather variable elsewhere in the CloudWatch world.
Northern Poland, southern Sweden and the south-east of Norway had the sunniest weather in Europe today. Bor's School in southern Sweden had no more than two oktas (eighths) of cloud all day, and even that appeared to be generated by aircraft. At Lännbo Friskola (Stockholm), they had a cloudless sky with no contrails this morning. The skies were largely free of cloud at the other schools in the Stockholm area (Alviksskolan and the International School of Stockholm). The weather was quite sunny, too, at the CloudWatch school in Finland. The clouds that were present were mostly cumulus clouds. These can be seen clearly on the images from polar-orbiting satellites.
As on previous days, there was cumulus activity over the sea to the west of Norway, where cold air crossed warmer water and therefore became unstable. Heavy showers occurred over the northern half of Norway, where the cumulus activity was enhanced by orographic lifting of the onshore winds. There was cumulus activity over the northern half of Sweden and the whole of Finland. See, particularly, the 0810, 1238 and 1418 UTC Channel 1 images from Dundee. These images show that most of the northern half of the Gulf of Bothnia was covered with ice. They also show that ice covered the sea east of Greenland and off the eastern side of Svalbard. Polar pack-ice can also be seen north of Svalbard.
To the west of the cold front that crossed the British Isles today, there were showers in abundance. The speckled and cellular patterns of clouds that are so characteristic of cumulus and cumulonimbus activity can be seen clearly on satellite images. See, particularly, the 1559 UTC Dundee Channel 1 and Channel 4 images. Charts of sferics (electrical discharges associated with lightning) show that some of the cumulonimbus clouds over Ireland and the ocean to the west of Ireland produced lightning. There was lightning activity over southern Germany, too, and over the south-eastern corner of France, not far to the west of Turin. On the 1530 UTC Meteosat D2 infra-red satellite image, the cumulonimbus cluster that produced the lightning can be seen clearly as a sizeable white patch.
In the Alps and the Cevennes, there was cloudy weather today, with rain at St George's School, Switzerland, this afternoon and the Eagle's Nest last night. In Spain, cumulus clouds built up during the day, but the weather was quite an improvement on earlier in the week. The weather was very pleasant in Malta.
To finish, we note that St Hilda's High School in Liverpool observed a sundog today.
These images, whose reference numbers begin with an E, provide information about moisture in the atmosphere, particularly the upper troposphere. The whiter the image, the moister the atmosphere. The water vapour images for Europe and North Africa have the code E2. For today's E2 images, click here.
Do you have attached to your car a thermometer that shows you, as you drive along, the temperature outside? If so, you might like to investigate temperature changes from place to place and minute to minute on a showery day. These changes can be considerable. The Education Officer of the Royal Meteorological Society once made a journey on a day of heavy showers from a place about 80 kilometres north of London to Cardiff in South Wales (a distance of about 240 km). The temperature on this June afternoon fluctuated between 20°C and 10°C, being lowest in the cold downdraughts of the cumulonimbus clouds. You can, of course, stay in the same place and measure temperatures as cumulonimbus clouds pass over you, but you cannot be sure a downdraught will actually pass over your observing site! Going cumulonimbus chasing can be fun, but beware - cumulonimbus clouds can be dangerous. They can produce hail, lightning and, sometimes, tornadoes.
Here is a selection to choose from - a different selection from yesterday's (click on the name):
Oslo/Gardermoen | Amsterdam/Schiphol | Strasbourg | Krakow | Clermont-Ferrand
Bolzano (Bozen) | Geneva-Cointrin | Malta/Luqa | Madrid/Barajas | Valencia/Aeropuerta
Inverness/Dalcross | Stornoway | Wick | Newcastle | Jersey
For other stations in Great Britain, click here.
On the chart for your region, you should find a weather station fairly near to you or even very close to you. On the chart for Italy, for example, there is an observation for Malta, and on the chart for Scandinavia you can find observations for Bergen, Oslo and Stockholm. On the chart for Spain, observations for Madrid and Valencia can be seen.
Austria | Belgium | Czech Republic | Denmark | Finland | France | Germany | Hungary
Italy | Jersey | Latvia | Lithuania | Netherlands | Norway | Poland | Portugal | Russia
Spain | Sweden | Switzerland | United Kingdom
