|
|
|
|
|
|
|
|
Click on today's infra-red satellite images below for full size version (source: Nottingham University)
|
|
|
|
|
|
|
|
Rain before seven, fine before eleven. So the old adage says. Well ... it was raining before seven this morning in the Reading area and the rain stopped before eleven. However, it started to fall again soon after eleven!!! It just goes to show that you mustn't rely upon weather lore. Those whose job it is to forecast the weather got it right. As you will see from the observations we received today, the weather was, as predicted, overcast, mild and damp over much of England and Wales, with winds from a westerly point. Farr High School, in the north of Scotland, reported sunny intervals and showers with strong winds. Everywhere in the British Isles, the weather was mild, with maximum temperatures over 10°C in most places.
Why were the winds from a westerly point? Well ... pressure was high across Europe from France to the Black Sea and low to the north of Scotland and in Scandinavia. Winds blow anticlockwise around depressions in the northern hemisphere and clockwise around anticyclones, so westerly winds were to be expected over the British Isles. The winds transported across the British Isles air that had passed over the waters of the eastern North Atlantic Ocean, hence the comparatively high temperatures for the time of year.
Incidentally, a westerly wind is one that blows from the west; an easterly wind is one that blows from the east. This can be confusing, as we can use the word 'westerly' to mean towards the west, and this is true in oceanography. A westerly ocean current is one that flows towards the west. In meteorology, though, I repeat that a westerly wind is one that blows FROM the west. A northerly wind is one that blows FROM the north. And so on.
Buys Ballot's Law can be used to work out where depressions and anticyclones are located. This Law states that, in the northern hemisphere, low pressure is on your left if you stand with your back to the wind, high pressure on your right. The opposite holds in the southern hemisphere. It's wise to stand with your back to the wind. In cold weather, having the wind blow in your face can be unpleasant. In very low temperatures, it can be dangerous. C H D Buys Ballot was, by the way, a Dutchman. He lived from 1817 to 1890 and was for many years Director of the Royal Netherlands Meteorological Institute.
As predicted, a depression moved into Scandinavia today, bringing with it strong winds and precipitation. There was snow in Finland and there were showers in northern and central parts of Norway.
Unfortunately, the database was somewhat depleted today, because a major communications problem occurred. The link between Reading University (where the database resides) and Britain's Joint Academic Network (known as JANET) was lost about 22:00 GMT (UTC) yesterday evening. It was not fully restored until about midday today.
We did receive a report from our school in Edmonton, where the sun shone, pressure was quite high (1028 mb) and the temperature quite low (-12°C at 09:00 their time, which is 16:00 GMT/UTC). It was something of a contrast in south-east Australia, where the weather was again very hot. The northerly winds brought hot air from the interior of Australia and lifted the temperature at Melbourne Airport to 38°C at 3 pm local time (04:00 UTC). At 6 pm local time, widespread dust was reported at the airport. How does the weather affect people in these two contrasting climates? What effect will the weather have on the pupils of our schools in Alberta and Victoria so far as choice of weekend activities is concerned? James Gibbons School, Southmoor Primary School and Trinity Grammar School, please tell us.
The weather sounded much nicer today in Portugal than yesterday, when Gabriel Pereira School reported fog. "Spring-like" was a comment made today. It wasn't so nice in Malta, where Achille Ferris had quite a lot of cloud and fairly strong winds. Vidal's weather sounded very pleasant: no cloud and a temperature of 17.7°C.
At Addis Ababa at 09:00 UTC, the sun was shining from a cloudless sky and temperature was 20°C. The wind was quite strong though, hence the school's report of "cold in the morning". Mind you, a temperature of 20°C would be very nice to us here in the UK just now, with or without the wind! In southern Africa today, there was again a lot of cloud. A depression again lay over southern Mozambique and plenty of shower clouds lay over Zambia and Zimbabwe, but that is not at all unusual, as this is the rainy season in those two countries. In Uganda and Oman and at Bombay and Ascension Island, satellite images suggested that skies were largely free of cloud. I wonder how the pupils of the MetLink schools in these parts of the world will take advantage of the weather this weekend.
The hottest part of the MetLink world was again south-east
Australia, but the temperature was not quite as high as the previous
day. At Melbourne Airport, the best they could manage today was
'only' 38°C!! Here is the afternoon's sequence of temperatures,
wind speeds and wind directions at the airport,
obtained
from the
Internet
Weather Source provided by the
US National Weather Service (X
= no data; local noon = 01:00 UTC):
|
TIME |
Noon |
1 pm |
2 pm |
3 pm |
4 pm |
5 pm |
6 pm |
7 pm |
8 pm |
|
TEMP |
33°C |
X |
36°C |
38°C |
36°C |
35°C |
34°C |
35°C |
33°C |
|
WIND |
N |
X |
N |
N |
NW |
NNW |
N |
N |
N |
|
(mph) |
18 |
X |
16 |
18 |
21 |
9 |
12 |
14 |
11 |
The sudden change in wind direction that occurred between 4 and 5 pm the previous day did not occur today. Thus, it appears that a sea-breeze front did not travel as far inland as Melbourne Airport. There certainly were, however, sea breezes along the coasts of Australia today, as charts available from the University of Cologne showed clearly.
Notice again that winds from the north bring hot weather to the Melbourne area. The charts from the University of Cologne show both winds and temperatures. The chart for 06:00 UTC (5 pm local time in Victoria) shows temperatures in the mid-twenties Celsius on the coast, 38-40°C inland.
Once again, smoke was reported hour after hour at Bombay's Santa Cruz Airport, indeed every hour from 13:00 UTC (18:30 local time) on 3 February to 02:00 UTC (07:30 local time) on the 4th. And smoke was again reported at 04:00 and 05:00 UTC. Can someone explain the cause/source of the smoke. Was it pollution trapped under a night-time inversion? Is there an industrial area close to the airport? The winds were either calm or light northerly throughout the period in question.
The Internet Weather Service observations obtained from Bulawayo Airport and Harare Airport revealed that Zimbabwe had drizzle and showers. The CTOT and DTOT Meteosat images show that the Intertropical Convergence Zone (ITCZ) covered Zambia and Zimbabwe. The ITCZ was also active over Zaire and northern Angola; and it was well marked over the Atlantic from the African coast (between the equator and about 5°S) to the middle of the equatorial Atlantic near 20°W. At Hilton College, our MetLink school in Kwazulu-Natal, South Africa, skies were clear. Not far to the north, however, there was a mass of cloud associated with a depression over Mozambique.
As weather charts for north-west Europe and adjacent parts of the North Atlantic Ocean show, pressure was low to the north of Scotland and high across Europe from France to the Black Sea. A depression moved into Scandinavia, bringing with it strong winds and precipitation. There was snow in Finland and there were showers in northern and central parts of Norway. Most places in the British Isles had some rain today, and Farr High School, the most northerly MetLink school in the UK, once again had a windy day, this time with wintry showers. Over most parts of England and Wales, as the observations from MetLink schools show, the weather was cloudy, dull and damp.
Unfortunately, the database was somewhat depleted today, because a major communications problem occurred. The link between Reading University (where the database resides) and Britain's Joint Academic Network (known as JANET) was lost about 22:00 GMT (UTC) yesterday evening. It was not fully restored until about midday today.
We did receive a report from our school in Edmonton, where the sun shone, pressure was quite high (1028 mb) and the temperature quite low (-12°C at 09:00 their time, which is 16:00 GMT/UTC). We also heard from Portugal, where the weather was described as "spring-like" at the Gabriel Pereira School. At Vidal, too, the weather was pleasant, with a sky clear of cloud at 12:00 UTC and a temperature of 17.7°C. At our school in Malta, though, Achille Ferris, there was a fairly strong wind from the north-west and quite a lot of cloud. Pressure was low over southern Italy and a weak cold front was present near Malta for part of the day.
At our school in Addis Ababa, there was a cloudless sky at 09:00 UTC, but the wind was strong. Thus, despite a temperature of 20°C, the day felt cool. In Uganda and Oman and at Bombay and Ascension Island, satellite images suggested that skies were largely free of cloud. I wonder how the pupils of the MetLink schools in these parts of the world will take advantage of the weather this weekend. Wherever you are, we'd like to hear from you. How did the weekend weather affect YOUR leisure activities?
