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School Weather News 1999
From:
education@royal-met-soc.org.uk
Subject: MetLinkInternational Week 2 Friday
Date: Fri, 5 Feb 1999 23:25:49 -0000
Dear MetLink friends
It's difficult to know where to start today, as no-one seems to have
had any really remarkable weather, but as I know someone who has just
returned from a business trip to Helsinki, I'll start in Scandinavia.
He reported that there was a lot of snow lying in Helsinki - almost a
metre depth, he estimated. And at
Eno and
Vora today, snow was
falling. This was associated with a deep depression which at 1200 GMT
was centred a little to the south of Helsinki - over Tallinn, to be
precise. An occluded front associated with this Low gave snow over
southern Finland and a band of squally snow showers extended in an
arc from Tallinn to Stockholm to Trondheim.
North of these bands of precipitation, winds were from the east or
north-east and temperatures quite low, but nowhere near as low as a
week ago. Around the White Sea at 1200 GMT today, values of about -35
deg C were to be found, and across northern Finland, Sweden and
Norway values of -15 to -20 deg C were to be found. Over Estonia,
Latvia, Lithuania and western Russia, temperatures were in the range
-15 to -30 deg C, but over southern Scandinavia winds were from the
north-west and temperatures a few degrees above freezing.
Over the North Sea and Denmark, winds were from the north-west and
quite strong, reaching gale force in many places. The cold front of
the Low near Helsinki lay in an arc across central and western
Europe, giving heavy showers - of snow in some places, rain in others
and hail in a few. In an arc extending from Ukraine across the
Carpathians, the Plain of Hungary and southern Germany to north-east
France, there were showers on this cold front -- and there were light
showers in southern England, too. Over the whole of the British Isles
today, winds were from the north-west and the air somewhat fresher
than it has been recently.
There was again today, as there was a few days ago, a Low (1010 mb)
over the Ligurian Sea, giving
Malta north-westerly
winds. Though these winds were still quite cool for the Mediterranean
(13 deg C reported at Achille
Ferris Primary School, Malta today), Malta's weather otherwise
appears to have been quite pleasant. Do you agree, Alfred?
================
Here's a response from Alfred in Malta to the question I asked
MALTA WEATHER RESPONSE >>>>>
I agree with your information given. Here in Malta the weather is becoming stable and warmer. Due to a trough of low pressure extending from Russia to the Gulf of Sirte we still have some strong wind. Cold is diminishing and more sunny periods help us feel better. The Temp is already 14c.
================
Tarragona's
weather report indicates a nice day, with no wind and lots of
sunshine. The weather chart for 1200 GMT issued by the British
Met.Office shows closely- packed isobars over the south of France,
indicating strong northerly winds. The Mistral MUST have been
blowing through the Rhone Gap today. Has anyone any information,
please?
=============
MISTRAL RESPONSE >>>>>>
In my review of today's weather, I said that there must have been a mistral blowing in southern France that day and I asked if anyone had any information. A response has come from a friend in the UK's Meteorological Office. There was indeed a mistral blowing. Here are some observations made in southern France at 1200 UTC on Friday 5th, February. The figures are, respectively, cloud amount; wind direction (in degrees, with 090 = from the east, 180 = from the south, 270 = from the west); wind speed (in knots); temperature and dew-point temperature (in deg C); sea-level pressure (in millibars); pressure fall in the previous three hours (in mb):
Carcassonne: 7/8 290 23 9.9 4.7 1027.6 2.1
Montpellier: 2/8 300 23 15.1 3.9 1021.2 2.7
Nimes-Courbessai: 2/8 350 19 15.6 2.1 1020.0 2.6
Marseille-Marignane: 1/8 350 37 14.0 4.0 1017.9 1.8
Cap Cepet (43*05'N 05*56'E): 2/8 310 31 14.2 3.7 1013.7 1.7
LeLuc: ?/8 290 29 19.1 0.3 1009.4 3.7
Perpignan: 3/8 300 19 14.0 3.5 1025.0 1.4
Cap Bear (42*31'N 03*08'E): 3/8 340 62(??) 12.8 4.0 1019.1 2.1
Cap Bear reported the wind gusting to 74 knots!
There are some very interesting figures here. Notice, for example, how much lower the relative humidity is on the lee side of the mountains of southern France. Can you explain anything in terms of the Bernoulli effect?
If anyone is interested, I can supply details of the clouds at each place.
Best regards Malcolm
====================
After looking like the textbook model for several days, the ITCZ has
become very indistinct again, with hardly any cumulonimbus activity
on it. There was cumulonimbus activity over and immediately to the
south of Harare, though, and also off the east coast of
Madagascar, as the
ETOT Meteosat image shows clearly. Just
to the south of Harare, there was a Low of 1003 mb, and off
Madagascar, too, there were some centres of low pressure (about 1010
mb). High pressure has remained the dominant influence at
Tristan da Cunha today,
but a cold front from a depression near South Georgia appears to be
approaching Tristan.
That's all for today and, indeed, for the active phase of MetLink'99.
Now we move to the review phase. I leave you today with one of my
'pet hates'. Why do the weather presenters on the radio and TV in the
UK say "Tomorrow we shall see temperatures of .....". We don't SEE
temperatures!
Bye for now and best regards Malcolm
