"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
...

"Adrian D. Shaw" wrote in message
...

Radio 4 17:57 forecast said there was a record breaking frost last night
somewhere in Oxfordshire.

I shouldn't really be surprised because it happens so often, but the
handling of climatological information by the BBC Weather Centre
continues to be excruciatingly embarrassing. Here are a few facts to
help us judge what to make of the above statement which has appeared
regularly throughout the day in pretty much the same form (I've even
had to field press enquiries about it):

1. The quote actually refers to RAF Benson. Benson was not a
seven-days a week station until 1974.

2. The enclosure at Benson moved in the mid-1990s ... it is now more
open and 4m lower, and a quick eyeballing of the records shows that
it is now more susceptible to low readings on radiation nights. A
comparison
with adjacent stations confirms this. Comparisons with the records before
then are therefore entirely illegitimate.

3. It was not remotely an Oxfordshire record. This was lazy shorthand
by the perpetrator who knew that nobody had heard of Benson but
a few listeners in their new, dumbed-down world might conceivably
have heard of Oxfordshire. Lower readings were observed at
Wallingford (a couple of inches away on the OS map) during the
Junes of 1996 and 1991 for instance (haven't checked back any further).

4. The CET minimum for last night has a return period (for June) of
just three years. Certainly a few scattered individual locations will
have had their coldest June night for a lot longer (since 1991 here in
Luton, for instance) but that's in the nature of these sort of records.

5. Minima below zero occur somewhere or other in the UK in June
every other year, on average. Last night did not even produce the UK's
lowest temperature so far this month; that was -1.4°C at Altnaharra
the previous night, but we know that Scotland doesn't count, don't we?

6. In summary, then, it was averagely cold night.

7. Much more unusual is the sea-level pressure which got close to 1039
mbar this morning ... probably (haven't done an exhaustive check) the
highest
since 7th June 1962. The June record for the British Isles, as we
discussed a
couple of days ago, is 1043.1 mbar in 1959 (original source: S.D.Burt).

Philip Eden




Well done Philip :-)

Gavin.