I'm a bit surprised at the minimum temperatures forecast on BBC1 at 6.30
p.m. this evening. Single figure mins were predicted for Scotland but
elsewhere double figure mins were predicted. I haven't looked into it in
much detail but for this part of the country the McKenzie method
predicts a min of around 7-8C, assuming light winds and only small
amounts of cloud. This would be quite a bit colder than the TV forecast
suggested.

I have noticed for some time now that the forecast minimum temperatures
seem to err on the high side on radiation nights. I'm not certain but I
think that this apparent systematic error started at the time of the
introduction of the new graphics. It may be a presentation problem
rather than a forecasting problem.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England

"Norman Lynagh" wrote in
message ...
I'm a bit surprised at the minimum temperatures forecast on BBC1 at 6.30
p.m. this evening. Single figure mins were predicted for Scotland but
elsewhere double figure mins were predicted. I haven't looked into it in
much detail but for this part of the country the McKenzie method predicts
a min of around 7-8C, assuming light winds and only small amounts of
cloud. This would be quite a bit colder than the TV forecast suggested.

I have noticed for some time now that the forecast minimum temperatures
seem to err on the high side on radiation nights. I'm not certain but I
think that this apparent systematic error started at the time of the
introduction of the new graphics. It may be a presentation problem rather
than a forecasting problem.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England

Currently 10.4 so single figures soon.
I recall that when the graphics were first introduced one of the presenters
saying that the mins were for towns and cities. I assume that as the
majority live there that the mins indicated are more relevant to them than
us rural dwellers.

--
David Mitchell, 70m amsl, Langtoft, East Riding of Yorkshire.

Norman Lynagh wrote:

I'm a bit surprised at the minimum temperatures forecast on BBC1 at 6.30
p.m. this evening. Single figure mins were predicted for Scotland but
elsewhere double figure mins were predicted. I haven't looked into it in
much detail but for this part of the country the McKenzie method
predicts a min of around 7-8C, assuming light winds and only small
amounts of cloud. This would be quite a bit colder than the TV forecast
suggested.

I have noticed for some time now that the forecast minimum temperatures
seem to err on the high side on radiation nights. I'm not certain but I
think that this apparent systematic error started at the time of the
introduction of the new graphics. It may be a presentation problem
rather than a forecasting problem.

Norman.
(delete "thisbit" twice to e-mail)


I think the BEEB have dumbed down their mins, giving the likely temperature
when your average Joe Sixpack is leaving for work, rather that the actual
min.

This seemed coincide with the new graphics. You may notice that when they
show/talk about mins the screen says 8am or thereabouts.

I used to watch the BBC forecasts a couple of times a day. I'm down to a
couple of times a week now and think I'll stop soon.


--
Brian Wakem
Email: http://homepage.ntlworld.com/b.wakem/myemail.png

Norman Lynagh wrote:

I'm a bit surprised at the minimum temperatures forecast on BBC1 at
6.30 p.m. this evening. Single figure mins were predicted for
Scotland but elsewhere double figure mins were predicted. I haven't
looked into it in much detail but for this part of the country the
McKenzie method predicts a min of around 7-8C, assuming light winds
and only small amounts of cloud. This would be quite a bit colder
than the TV forecast suggested.
Norman.
(delete "thisbit" twice to e-mail)
snip...

I agree -- a rough calc using Tmax of 17 and Td of 8 with very light wind
and little cloud produces a min of around 8C. (this is for the Finningley
area)..
The discontinuity of 11.5 is not too far from present temp of around 12C
with patches of decaying CU.
John
--
York,
North Yorkshire.
(c.20 metre AMSL)

9.1C here at the moment in Dudley. It is the 4th night in succession that
the temperatures have gotten down into single figures. Radiation fog and
frost, i would think is not very far away.

Mike
www.dudleyweather.pwp.blueyonder.co.uk

"John Whitby" wrote in message
...
Norman Lynagh wrote:

I'm a bit surprised at the minimum temperatures forecast on BBC1 at
6.30 p.m. this evening. Single figure mins were predicted for
Scotland but elsewhere double figure mins were predicted. I haven't
looked into it in much detail but for this part of the country the
McKenzie method predicts a min of around 7-8C, assuming light winds
and only small amounts of cloud. This would be quite a bit colder
than the TV forecast suggested.
Norman.
(delete "thisbit" twice to e-mail)
snip...

I agree -- a rough calc using Tmax of 17 and Td of 8 with very light wind
and little cloud produces a min of around 8C. (this is for the Finningley
area)..
The discontinuity of 11.5 is not too far from present temp of around 12C
with patches of decaying CU.
John
--
York,
North Yorkshire.
(c.20 metre AMSL)

I caught the end of the local BBC forecast tonight and Peter Cockroft
said the region's cold spot would be Redhill at 6 deg C.

Currently (22z) 11.5 deg C at Redhill.

--
Tom
Chelmsford, Essex (109m)
http://www.meteocare.co.uk

On Thu, 25 Aug 2005 22:13:06 GMT, "Michael Di Bernardo"
wrote:

I agree -- a rough calc using Tmax of 17 and Td of 8 with very light wind
and little cloud produces a min of around 8C. (this is for the Finningley
area)..

Here in Fareham at 2350GMT it was 11 deg C - the same as 1150Z (at
Southampton - estimated for here) yesterday. Pretty unusual in August
in this area, I'd say.

Last night it got down to 10 deg C here and tonight, I'm expecting...
single figures. No "town centre" excuse from the BBC will wash with
me, as most people probably live in the suburbs. And that is precisely
where I am - in typical suburban Southern England.

--
Dave
Ferahm (West).

In uk.sci.weather on Thu, 25 Aug 2005 at 18:43:39, Norman Lynagh wrote :

I have noticed for some time now that the forecast minimum temperatures
seem to err on the high side on radiation nights.

I totally agree - in such cases I almost inevitably record several
degrees below what they forecast - and I'm by no means in a rural area.
--
Paul Hyett, Cheltenham

In uk.sci.weather on Thu, 25 Aug 2005 at 20:30:27, David Mitchell wrote
:
I recall that when the graphics were first introduced one of the presenters
saying that the mins were for towns and cities. I assume that as the
majority live there that the mins indicated are more relevant to them than
us rural dwellers.

But how large does a town have to be to generate a significant heat
island?

I'm only about 1.5 miles from the centre of Cheltenham (in a suburban
area), and their forecast night temperatures are almost inevitably above
what I record.
--
Paul Hyett, Cheltenham

On Fri, 26 Aug 2005 07:10:36 +0100, Paul Hyett
inspired by Deep Thought wrote:

In uk.sci.weather on Thu, 25 Aug 2005 at 18:43:39, Norman Lynagh wrote :

I have noticed for some time now that the forecast minimum temperatures
seem to err on the high side on radiation nights.

I totally agree - in such cases I almost inevitably record several
degrees below what they forecast - and I'm by no means in a rural area.

Likewise Paul, I usually knock 4-5C off the BBC predicted temperatures and I
usually end up not far from the actual temperature. This has been the case for
most of this summer. The Hooray Henry phenomenon at the BBC raising its head
again?

The highest temperature recorded here yesterday was just 17.8C. In the last 7
days the max temperature has only hit 20C on two of those days - last Sunday &
Tuesday, and for three out of those seven it struggled to reach 15C!! One of the
coldest and wettest August weeks I can remember for a good few years!

Nigel

Aagh! Every time I learn something new... it pushes something old out of my brain!