"Dick" schreef
"I have always assumed that the maximum temperatures that Colin lists
are for the 24 hours ending at 1800 GMT."
___________________

Actually for the 12 hours ending 18.00 GMT - as reported in the 18.00 synop.
___________________

"On this basis ... the High
Wycombe value is wrong. It should be 9.0C and not the quoted 7.4C. The
value of 7.4C looks to be either the 2100-2100 or 0900-2100 GMT
maximum."
___________________

7.4°C reported as the 12-hour maximum at High Wycombe in the 18.00 synop.

Colin Youngs
Brussels

"Martin Rowley" schreef

: On 17/03/2012 11:10, John Hall wrote:
: ... Presumably the High Wycombe maximum is since 9am only, as I
: imagine that it would have been warmer than 7.4C at 6pm the previous
: evening.

: ... just to answer John's query, from the SYNOP reports, the highest
: hourly in the period 15/1800 to 16/1800Z was 9.0°C at 15/18Z. I don't
: know how WeatherOnline sort their maxima out so can't comment on that
: aspect.

WeatherOnline temperature maps that I link to show the 12-hour synop
reports: 18.00 previous day to 06.00 current day for min. temps and 06.00 to
18.00 current day for max. temps. Rainfall map shows the 24-hour totals
18.00 previous day to 18.00 current day.

: ... 'High
: Wycombe' is not really a very 'representative' name for the observing
: location. It is ... sitting on top of the bunker at
: the facility which has as it's nearest village Walter's Ash.

Perhaps I should rename it "High Wycombe (Walter's Ash)" by analogy with
"Bournemouth (Hurn)" !

: ... the observing
: point is listed as 204 m amsl, c.f., a figure of around 100-120 m for
: the middle of High Wycombe (and 5 m for St. James' Park).

I had wondered why High Wycombe often seems to be relatively cold. That
explains it.

Colin Youngs
Brussels

Colin Youngs wrote:
"Roger Smith" schreef

... I thought that the "day" defining the Tmax figures in the Colin's
tinyurl reference to the Met Office website is the period
0900-2100hrs.

Most of the temperature figures I quote come from the 06.00 and 18.00
synops and cover periods of 12 hours ending at the synop times:

Min. temps: 18.00 on the previous day to 06.00 on the day in question.
Max. temps: 06.00 to 18.00 on the day in question.

Rainfall totals are for the 24 hours from 18.00 on the previous day
to 18.00 on the day in question (the two 12-hour synop totals added
together).

I also look at the lists on OGIMET, which show the 06.00 min. temps
and
18.00 max. temps, for Charlwood, Exeter, Mona, Leek, Albemarle,
Woodford and St James's Park.

Those figures refer to the previous 24 hours, so I try to exclude any
values which fall outside the synop 12-hour periods.

In this case, I overlooked the fact that the 15.0°C at St James's
Park was recorded the previous day - as Dick Lovett has pointed out.

Colin Youngs
Brussels

Colin, thanks for the clarification - something was wrong somewhere!

Roger

On 17/03/2012 14:56, Colin Youngs wrote:
snip
I had wondered why High Wycombe often seems to be relatively cold. That
explains it.


.... In my view, it is so meteorologically / climatologically different
from High Wycombe that it needs to be divorced from that town. At least
Hurn is roughly within the same climatological 'basin' (though just
outside Bournemouth council area - it's actually in Christchurch council
area).

The station 03660 is situated on a military facility - it's still listed
as HQSTC on OgiMet, though it's now part of HQ Air Command, RAF (and
they refer to it as being at Naphill**). There's nothing particularly
'secret' about all this as there are plenty of references in published
literature to the place; I remember distinctly in the 1980s when I was a
member of the National Trust being asked to comment on/ vote on, the
NATO wish to build the nuclear bunker on part of NT land.

The location is here ....

http://www.streetmap.co.uk/map.srf?X...8600&A=Y&Z=126

It's a bit like using Bishopton to describe the conditions in Glasgow!

[** The HQ unit stands on the 'greater' RAF High Wycombe site, which
when built in the early stages of the War, had as its 'parent' village
Naphill - the largest unit with a few shops, pubs etc., at the time.
Walter's Ash was simply a small hamlet of a few cottages strung out
along the road leading to Lacey Green and Loosley Row; nowadays, with
the expansion of the domestic RAF site and associated services, Walter's
Ash is the larger community, but the RAF retain the association with
Naphill.]

Martin.


--
West Moors / East Dorset
Lat: 50deg 49.25'N, Long: 01deg 53.05'W
Height (amsl): 17 m (56 feet)
COL category: C1 overall