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Sources: BBC, National Weather Services, Intellicast, Space Science and Engineering Center, the Met Office, Yahoo! Weather
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TODAY’S HEADLINES
TODAY’S EXTREMES
Hottest: Medan International School, Sumatra, Indonesia, 33.0°C
Coldest: Vörå-Oravais-Maxmo Högstadieskola, Finland, -21.6°C
Windiest: Portgordon Primary School, Morayshire, UK and St Patrick’s Primary School, near Preston, Lancashire, UK: both 81 km/h
Driest: Pasadena City College, California, USA, relative humidity 12%
Wettest: Bischöfliches Gymnasium St Ursula, Geilenkirchen, Germany, 90 mm of rain
IMAGES OF THE DAY
To find this feature, click here.
TODAY’S REVIEW OF METLINK OBSERVATIONS
Have you looked at today’s weathercams? If not, click here.
To view today’s observations in the database, click here.
To find out how your observations compare with the average for January, click here.
AUSTRALASIA
Fine, clear and cold at Keio in Japan at 01:00 GMT (10 am Local Time). Temperature 13.2°C and relative humidity only 27%. Hot and humid in Jakarta, Indonesia, with a temperature of 25°C and relative humidity of 95% at 00:00 GMT (7 am Local Time). Very little rain, though, compared with yesterday. Range of temperature small: 32°C maximum; 24°C minimum. Sunny, humid and hot at the Medan International school, where the temperature was also 25°C at 00:00 GMT (8 am Local Time). Temperature ranged from 33.0°C maximum to 22.0°C minimum. No rain during the previous 24 hours.
Temperature slightly below average at New Delhi, where the maximum temperature was 19.5°C, the minimum 5.7°C and the temperature at 09:45 GMT (3.15 pm Local Time) 18°C. Mist and fog in the morning. Sunny by noon.
AFRICA AND ASCENSION
Bright and humid at Two Boats School at 12:40 GMT (12.40 pm Local Time) but slight drizzle falling. Four oktas of cumulus and cumulonimbus cloud. Temperature at 12.40 pm 26°C and the wind speed 24 km/h.
Breezy (24 km/h) and a temperature of 27°C at Kampala at 10:00 GMT (1 pm Local Time). Quite cloudy, with 7 oktas of stratus reported. Quite cloudy, too, at Highbury Preparatory School in KwaZulu Natal, South Africa, with 7 oktas of stratocumulus cloud at 05:00 GMT (7 am Local Time). Temperature then 19°C, compared with a maximum of 28°C and a minimum of 18°C. "Cooler after the welcome rain last night" was the comment of the students. Slight rain falling at Pretoria Boys’ High School in South Africa at 08:20 GMT (10.20 am Local Time). Temperature then 25.9°C (maximum 26.1°C, minimum 21.6°C). Dry and partly cloudy (4 oktas of cumulus and stratocumulus cloud) at Peterhouse, Zimbabwe, at 06:00 GMT (8 am Local Time) today. Temperature then 22.7°C. Maximum 27.7°C, minimum 22.1°C.
Cyclone Dina today south-east of Madagascar.
EUROPE
"White and cold" and overcast, with slight snow falling, at Vörå in Finland at 11:10 GMT (1.10 pm Local Time). Temperature then -10.9°C, which was something of an improvement after a minimum of –21.6°C! Slight snow falling at Mikkeli in Finland, too, but cloud amount small (only 2 oktas of cirrus). Temperature at Mikkeli -20.4°C at 08:00 GMT (10 am Local Time). No precipitation falling at Jyväskylä in Finland at 11:40 GMT (1.40 pm Local Time), but the temperature then only –16.9°C. Maximum of –14.6°C and minimum of –19.1°C. A little less cold at Vasa in Finland, where, at 13:40 GMT (3.40 pm Local Time), the temperature was –5.4°C. Quite a contrast at Bor School in southern Sweden, where the temperature at 07:00 GMT (8 am Local Time) was +4.2°C and slight rain was falling. Cloud cover 8 oktas of nimbostratus. Maximum temperature there 5.5°C, minimum +3.4°C. Nimbostratus cloud over Oslo in Norway, too, where heavy snow was falling at 11:31 GMT (12.31 pm Local Time). Temperature then –0.9°C, having been down to a minimum of –5.9°C.
Sunny at Constanta in Romania today, where the temperature rose from 4.1°C at 06:00 GMT (8 am Local Time) to 7.1°C at 10:00 GMT and 9.0°C at 13:00 GMT before decreasing to 8.0°C at 16:00 GMT. "A beautiful day", the students reported. Very different at Bozen in northern Italy, where, at 15:00 GMT (4 pm Local Time), the sky was completely covered by nimbostratus cloud and slight rain was falling. "First rain after 2 months ends drought all over northern Italy", the students reported. Temperature 4°C at Bolzen at 15:00 GMT. Slight drizzle and occasional rain occurred on Malta today. Temperature at 09:00 GMT (10 am Local Time) 14°C and the wind speed 24 km/h. A cool day in Madrid, where the temperature was 5°C at 08:15 GMT (9.15 am Local Time) and 10°C at 14:20 GMT. Quite cloudy in the afternoon (6 oktas at 14:20 GMT) but no rain reported.
"A miserable wet and windy day" at Toulouse, where the temperature was 6.0°C at 11:00 GMT (12 noon Local Time) and the relative humidity high (95%). Reported rainfall amount 11 mm. Wet at Geilenkirchen in Germany, too, the comment of the students being "a wet day after a night with storm and a lot of rain". Temperature 8.0°C at 09:30 GMT. Rainfall amount 90 mm. Wind speed 33 km/h.
"Cooler today; beautiful hardy day; Connemara lakes like crystal" was today’s comment from St Theresa’s National School in Cashel, County Galway, Ireland. What a change from the recent wet and windy weather in Ireland. "A fine, clear, cold day" was the comment from Dublin’s Malahide Community School, where the temperature at 09:00 GMT was 8°C and the wind a breeze of 15 km/h. "A beautiful crisp winter’s morning with lots of winter sunshine" was the comment from Ennis, County Clare, where the temperature was 9°C at 09:30 GMT and the wind calm. Sounds like a very nice day to have been in Ireland.
"Clear, bright, sunny and cool with a gusting gentle breeze" at George Watson’s College in Edinburgh and a "very bright sunny day with a cold wind" at Queensferry, near Edinburgh. Cold, sunny and dry at Farr High School on the north coast of Scotland. Elsewhere in Scotland, though, conditions something of a contrast. A few light snow showers fell on the Isle of Lewis this morning and the weather was "mainly dull and wet" at Portgordon in Morayshire.
Over the northern half of England and Wales today, winds mainly from the north-west all day. Over southern parts, the day began with westerly winds but a change to north-westerly winds occurred during the morning. Quite windy in many places, with wind speeds reaching 80 km/h in some places. The day was dry but chilly in many places but started wet in some southern and eastern parts (most notably Norwich) and remained rather cloudy all day in some southern counties. The children at Pyrford Primary School in Surrey thought the day "cloudy and miserable" when they reported at 13:30 GMT, but the weather obviously improved a wee bit, for they reported at 15:00 that it was now cloudy but bright. At Chaldon in Surrey it was "cold, windy, damp and muddy" at 09:00 GMT. At Milford Haven in the west of Wales, it was a "blustery day with dark clouds" and at Delabole in Cornwall at 08:45 GMT there was slight rain and a "strong wind". In Reading, the home of the Royal Meteorological Society, the day was breezy, dry and partly cloudy with some sunny periods.
For a chart showing temperatures, significant weather and distributions of barometric pressure over Europe at 12:00 GMT today, click here.
NORTH AMERICA
At Raleigh in North Carolina, a slight drizzle falling at 12:52 GMT (7.52 am) and the sky completely overcast. The temperature 14°C and the relative humidity 100%. Oh dear! That doesn’t sound very nice. Across in Illinois, though, at Aurora, the weather was much better, though quite windy. It was, to quote the students, "a beautiful sunny day, chilly but refreshing". The temperature was +2°C and the wind speed 33 km/h. Cool but sunny at Fernley in Nevada, too, where the temperature at 16:50 GMT (8.50 am Local Time) was –4°C and the cloud amount only one okta. At Moses Lake in Washington State, the weather was rather cloudy and breezy but much warmer than of late. The temperature at 19:00 GMT (11 am Local Time) was 7.8°C. Sunny at all three schools in California, the warmest of the three localities being Pasadena, where the temperature at 19:55 GMT (11.55 pm Local Time) was 17°C. It was 14.7°C at 18:38 GMT at Reseda and 11°C at 20:53 GMT at Livermore. Once again, the weather was cold at Edmonton in Alberta, but not quite as cold as on previous days. The temperature was –14.0°C at 16:30 GMT (9.30 am Local Time) with a completely cloudy sky out of which light snow was falling. The maximum and minimum temperatures at Edmonton were, respectively -6.0°C and -19.0°C.
TODAY’S ANALYSIS
NB On the so-called ‘visible images’ from satellites, what you see is more or less what you would see with your own eyes if you were in the satellite and looking in black and white. On the so-called ‘infra-red images’, the whitest areas are the coldest and the blackest the hottest. Thus, high clouds show as white areas. Medium-level clouds and very cold land areas show as grey. For information about obtaining satellite images of the highest quality, see the Notes section below.
AUSTRALASIA
Today’s satellite
images of the western Pacific
and Australia again show that cold air was flowing out from eastern
Asia and becoming convectively unstable when it flowed across the
warmer sea towards Japan. When it first reached the sea, the air
remained free of cloud, hence the clear skies just off the coast. The
farther the air flowed over the sea, however, the more it was warmed
and moistened, until it became convectively unstable. Then, cumulus
clouds started to form. These are shown as speckled areas on the
satellite image. Cumulus clouds often form into lines, called
‘cloud streets’. Cumulonimbus clouds tend to group into
cells or clusters of clouds. For a chart showing weather observations
over Japan at 06:00 GMT today, click here. For the meanings of the symbols used on such
charts, click here.
Today’s weather
chart for Australia and
adjacent regions shows that barometric pressure was low over most of
Australia and high to the south of Tasmania. Visible and infra-red satellite images show that cloud amounts were
small over Australia today.
When studying the weather chart for Australia, remember that winds
blow clockwise around Lows in the southern hemisphere, anticlockwise
around Highs.
INDONESIA AND SOUTHERN ASIA
The world satellite composite from Wisconsin again shows the Intertropical Convergence Zone (ITCZ) running across the Indian Ocean from Africa to Indonesia and beyond, with largely clear skies over India. Notice how patchy and variable the ITCZ was again today. It was, like yesterday, very weak over the Atlantic Ocean but very active over Indonesia. The ITCZ consists of clusters of cumulonimbus clouds which rise to heights of 15 km or more. Heavy rain falls from these clouds. The visible and infra-red images from the geostationary satellite over the Indian Ocean reveal the ITCZ’s patchy features very clearly. Notice how wide the ITCZ is. It really is a zone. These two images show that Cyclone Dina was today south-east east of Madagascar. For a close-up of Dina taken yesterday, click here. Winds over southern Asia and the Indian Ocean at a height of about 1,500 metres at 00:00 GMT today are shown in the chart which is obtained by clicking here.
AFRICA
Today’s weather chart from the South African Weather Bureau again shows many depressions and fronts over the Southern Ocean between the parallels of 40°S and 60°S. It also shows Cyclone Dina to the south-east of Madagascar. A subtropical anticyclone cell (1025 mb) was centred south-west of Cape Town and another (1021 mb) was centred near Amsterdam Island (37°30’S 77°30’E). Pressure was again low over South Africa. The visible and infra-red satellite images of Africa at 12:00 GMT today show that ITCZ cloud covered much of central and southern Africa from about 5°N to about 15°S but was not as extensive as yesterday. These images also show that southern and south-eastern parts of South Africa were cloud-covered today, probably in association with a front that can bee seen on the weather chart running from south-eastward from near Durban to a depression centred south-west of Kerguelen. These images show, too, the clouds associated with the fronts of depressions over the Southern Ocean.
EUROPE
Today’s weather chart for 12:00 GMT shows that the depression which was over Ireland yesterday was today over Denmark, with a central pressure of 980 mb. Winds blew from the north-west across the British Isles, the west over northern France, the Low Countries and northern Germany. Pressure was low today, too, over the Atlantic Ocean south-south-east of Greenland (968 mb) and over the Ligurian Sea (1005 mb). Pressure was high over southern Spain (1029 mb) and eastern Turkey (1033 mb); and a low to the east of the White Sea (980 mb) continued to feed very cold air into Finland. The coldness of this air can be seen on the charts of temperatures, precipitation and significant weather for Europe and the Arctic. Notice that northern Scandinavia was today as cold as central Greenland but not as cold as northern Siberia, northern Quebec or the parts of Canada west of Hudson Bay. For a chart showing temperatures over Scandinavia at 06:00 GMT today, click here. For a chart showing minimum temperatures last night over Europe, click here. As can be seen, temperatures fell below -30°C in some places in northern Sweden. Today’s satellite images showed the clouds of the fronts over Europe and the Atlantic very clearly. Today’s chart of observations over the British Isles at 06:00 GMT shows that winds were then north-westerly over all parts except the south and east of England. To the south of the front which can be seen on the synoptic chart for 12:00 GMT lying from The Wash to Cornwall, winds were more westerly than north-westerly. The change from westerly to north-westerly occurred in Reading about 11:00 GMT. On the chart of observations, air temperature is the figure top left of the station circle. The barometric pressure change in the past three hours is the figure to the bottom right of the station circle. The figure top right is barometric pressure in tenths of a millibar. Put a 9 or 10 in front of the figure to obtain the value in mb. Thus, the pressure value at Cherbourg is 993.7 mb. For the meanings of the symbols used on these charts, click here. For a chart which shows snow depths and sea temperatures, click here.
NORTH AMERICA
Today’s weather chart and satellite imagery show fronts affecting many parts of central and eastern parts of North America, with high pressure over Nevada, California and the eastern Pacific Ocean. The cold front which runs from Maine to Texas and into New Mexico can be seen clearly on the satellite image, and so, too, can the clouds associated with the fronts of the depression that is centred over and to the south-east of the Gulf of Alaska.
To return to Today’s Review of MetLink Observations, click here.
LEE WAVES
What happens when air encounters hills? For an illustration of what happens when stable air meets a range of hills, click here. The picture you thus obtain is a visible image for 13:42 GMT today, showing parallel bands
The picture you thus obtain is a visible image for 12:00 GMT today, showing parallel bands of cloud over Wales, northern England and, to a lesser extent, central England. These are wave clouds, formed by orographic lifting. When stable air meets a range of hills, it is lifted and/or goes round the hills. Downwind of the hills, a train of lee waves is formed. Where the air goes up in these waves, clouds form, parallel to the hills. Where the air goes down, clouds dissipate. Today, winds were from the north-west and lee-wave clouds formed over and downwind of the hills of Wales and northern England. These clouds very often have smooth tops to them and sometimes look like lenses. When they do, they are called ‘lenticular’ clouds. When unstable air is lifted up the windward slopes of hills, cumulus and/or cumulonimbus clouds are formed. For another picture of orographically-formed clouds over the British Isles, obtained at 14:04 GMT two days ago, click here.
A GEOGRAPHY LESSON FROM SPACE
The visible image obtained from METEOSAT at 12:00 GMT today shows rivers, lakes and other features very clearly. It’s an image of superb quality. Can you find the Niger River, the River Nile, the Dead Sea, Lake Tana, the Zaïre River, Lake Mai-Ndombe, Lake Kariba and Cyclone Dina? What other rivers, lakes, etc can you find? Notice also the cells of cumulus and cumulonimbus clouds south-east of Newfoundland.
To return to Today’s Review of MetLink Observations, click here.
NOTES
You can obtain satellite images of the highest quality from the Dundee Satellite Receiving Station, Dundee University, Scotland. For further information, see the ‘Notes’ sections of the MetLink weather reports for 22 and 23 January.
To return to Today’s Analysis, click here.
OTHER NOTES
A school weather site that might be of interest to you is that made available by Scalloway School, Shetland, UK.
If you require information about climate on the web, click here. If you seek climatological data, click here or here.
