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School Weather News 1999
From:
education@royal-met-soc.org.uk
Subject: MetLinkInternational Day 3
Date: Wed, 27 Jan 1999 21:23:13 -0000
Dear MetLink friends
Before I review the day's weather ..... If you encounter any
difficulty with the data base, please will you let Roger Brugge
know.
Another matter ..... I have just remembered that I should encourage
you to transfer e-mails to floppy or hard disks so that your mail
boxes do not become full. The images you have been sent have been
quite large.
Now for today's weather .....
Without a doubt, northern Scandinavia must again take pride of place.
Record low temperatures in that part of the world have occurred, with
temperatures below -50 deg C last night across northern parts of
Norway, Sweden and Finland. Whatever happened to global
warming?! It was colder in Scandinavia than on the Antarctic
continent.
The lowest temperature I have found for the Antarctic was at Univ.
Wi. Id 8918, where it was -37 deg C with a windchill temperature of
-58 deg C
http://www.wunderground.com/global/stations/89744.html.
At Vostok
http://www.wunderground.com/global/stations/89606.html,
it was -33 deg C.
The lowest I have found this evening in Canada were -43 deg C at Old
Crow, Yukon, and -41 deg C at Eureka, North West Territories
(respectively,
http://www.wunderground.com/global/stations/71044.html
and
http://www.wunderground.com/global/stations/71917.html
Incidentally, I found current weather data for the South Pole station
on the Web a few weeks ago but now cannot find it any more. Please
send me the URL (Web address) if you find the site. Incidentally,
too, if you are interested in the Antarctic and its problems,
including the break- up of the ice shelves, you can start from the
British Antarctic Survey's home page, which is at
http://www.nerc-bas.ac.uk
The weather was spectacular in another way for Bedales School, as you
should know from an e-mail sent out today. A mini-tornado appears to
have crossed the area, damaging buildings, bringing down trees and
power lines, etc. In my review of Day 2, I drew attention to the
troughs crossing the British Isles. These were quite squally, and it
appears to have been one of the squalls that brought the havoc to the
area near Bedales.
Otherwise, there's nothing very exciting to report from the British
Isles. In Edinburgh and at the stations in England, we have seen
clouds associated with warm and occluded fronts but no rain or snow,
so far as I know. What precipitation there has been has been in
western parts of Wales and in Ireland? We had a weather report
from Pennar which indicated that they are becoming impatient for some
settled weather. What about Larne? Did you have a lot of rain
today? With the dominant weather feature an area of low pressure
(978 mb) between Iceland and southern Greenland, the British Isles
have been in moist air moving across the islands from the west, with
a weak ridge of high pressure over southern England. At Reading, the
pressure peaked at 1014 mb at about 1200 GMT.
An area of high pressure (1034 mb) is lying to the west of Spain,
giving winds from the north over the whole of Iberia. An area of low
pressure (998 mb) has been situated over the Ligurian Sea (to the
west of northern Italy). This is a classic mistral situation in the
Rhone Valley and over the Gulf of Lyons. Tarragona and Malta: have
you any information about this, please? And Malta: you have had a
cold front from that Low lying close to you. Have you seen much
evidence of it? The Low Countries and Germany got most of
Europe's precipitation today, in the form of rain, sleet and snow,
but there was snow from southern Sweden to western Russia, too.
Varnamo: how bad was your weather today?
There has again been a lot of cumulonimbus activity over southern
Africa, and again in an arc with a sharp southern boundary. At 1500
GMT, the arc lay from 15 deg S 35 deg E to 10 deg S 25 deg E and then
south-westwards to the Atlantic at 20 deg S 12 deg E, with
cumulonimbus cloud over land and then, abruptly, none over the sea,
indicating the impact of surface heating. Indeed, the sea off
south-west Africa is cool because of upwelling (in the Benguela
Current). The effect of the south-easterly trade winds is to drive
water away from the coast, whereupon it is replaced by cool water
from below. Can anyone find sea-surface temperatures on the Web to
tell us what the ocean surface temperatures are at the moment off
south-west Africa?
In Madagascar, it is tropical cyclone season. We wait with interest
to see if they experience a cyclone during the MetLink project. If
so, we hope it does not approach too closely. Tropical cyclones are
destructive weather phenomena. They bring very strong winds and very
heavy rain. At La Reunion island, there have been some phenomenal
falls of rain from cyclones over the years - like 160 cm in 24 hours
on one occasion.
Today's 1200 GMT chart of sea-level pressure shows low pressure over
south-west Africa, as it did yesterday, and light winds over Zimbabwe
and Zambia. There is still high pressure north-west of Tristan da
Cunha, but it has declined to 1017 mb. Not far to the south of
Tristan, however, there is a deep depression giving South Georgia and
Bouvet Island strong winds. But, then, those islands are in the
so-called 'Roaring Forties'.
Finally ..... what has happened to the Intertropical Convergence Zone
since yesterday? If you have looked at the
Meteosat DTOT image below, you will have
seen that it's a bit more active than yesterday, with an area of
activity near 2 to 5 deg N 10 to 15 deg W, but still nowhere near
continuous across the ocean. There is still quite a lot of cloud west
and south-west of the Canary Islands but it looks to be mostly
medium-level and high-level cloud now.
That's all for today. Good observing tomorrow!
