Brussels on Wednesday 12th December

Sunny and frosty start. Broken Sc moved in from the east in the late
morning. By early afternoon it was grey and misty and stayed like
that for the rest of the day. Fairly cold - little wind.

Brussels Uccle 6.0°C - overnight minimum -1.1°C.
Brussels Airport 3.3°C - overnight minimum -0.9°C.

Graph http://193.190.137.7/~celinair/maps/...ok/metr012.gif

Brussels Airport http://weather.noaa.gov/weather/current/EBBR.html

Rainfall radar http://www.buienradar.nl/h.aspx?jaar=-3&soort=loop24uur

OGIMET monthly summary for Brussels http://tinyurl.com/2qrego

Webcam Grand-Place http://www.ilotsacre.be/images/webcam/webcam.htm

Colin Youngs
Brussels

In article
,
Colin Youngs writes:
Brussels Uccle 6.0°C - overnight minimum -1.1°C.
Brussels Airport 3.3°C - overnight minimum -0.9°C.

That's a big difference in maxima over a shortish distance. Any idea of
the likely cause?
--
John Hall
"Honest criticism is hard to take,
particularly from a relative, a friend,
an acquaintance, or a stranger." Franklin P Jones

On 12 déc, 22:32, John Hall wrote:
In article
,

Colin Youngs writes:
Brussels Uccle 6.0°C - overnight minimum -1.1°C.
Brussels Airport 3.3°C - overnight minimum -0.9°C.

That's a big difference in maxima over a shortish distance. Any idea of
the likely cause?

Yes, John, I noticed that too. Uccle is in the southern outer
suburbs of Brussels. Brussels Airport is just outside the city to
the NE.

In a stable winter situation as on Wednesday - with a very gentle
drift from the NE - Uccle tends to be slightly warmer than the Airport
because it is downwind of the city "heat island".

On Wednesday Brussels was on the western edge of a large area of low
cloud and mist covering most of the eastern half of Belgium. Where I
work in the "European" area of Brussels - a couple of miles east of
the centre - most of Wednesday morning was fairly clear and sunny.
Towards the end of the morning the broken edge of the stratocumulus
layer moved over from the east. By 2 p.m. the sky was completely
overcast with increasingly poor visibility.

Perhaps the Airport was covered by the low cloud much sooner so that
the morning rise in temperature stopped at around 3°C. There may
also have been a drift of colder air from the east over the Airport
area, inhibiting the rise in temperature. At Uccle the sunshine will
have persisted until noon or so - perhaps long enough for the
temperature to rise nearly 3 deg. C higher.

Some combination of factors like this is the only explanation I can
think of. I agree, though, that the difference is surprisingly
large.

Colin Youngs
Brussels

In article
,
Colin Youngs writes:
On 12 déc, 22:32, John Hall wrote:
In article
,

Colin Youngs writes:
Brussels Uccle 6.0°C - overnight minimum -1.1°C.
Brussels Airport 3.3°C - overnight minimum -0.9°C.

That's a big difference in maxima over a shortish distance. Any idea of
the likely cause?

Yes, John, I noticed that too. Uccle is in the southern outer
suburbs of Brussels. Brussels Airport is just outside the city to
the NE.

In a stable winter situation as on Wednesday - with a very gentle
drift from the NE - Uccle tends to be slightly warmer than the Airport
because it is downwind of the city "heat island".

On Wednesday Brussels was on the western edge of a large area of low
cloud and mist covering most of the eastern half of Belgium. Where I
work in the "European" area of Brussels - a couple of miles east of
the centre - most of Wednesday morning was fairly clear and sunny.
Towards the end of the morning the broken edge of the stratocumulus
layer moved over from the east. By 2 p.m. the sky was completely
overcast with increasingly poor visibility.

Perhaps the Airport was covered by the low cloud much sooner so that
the morning rise in temperature stopped at around 3°C. There may
also have been a drift of colder air from the east over the Airport
area, inhibiting the rise in temperature. At Uccle the sunshine will
have persisted until noon or so - perhaps long enough for the
temperature to rise nearly 3 deg. C higher.

Some combination of factors like this is the only explanation I can
think of. I agree, though, that the difference is surprisingly
large.

Thanks, Colin.
--
John Hall
"Honest criticism is hard to take,
particularly from a relative, a friend,
an acquaintance, or a stranger." Franklin P Jones