In message
, Len
Wood writes
On Sep 25, 6:31*pm, "Jim Smith" wrote:
"Len Wood" wrote in message
...
On Sep 25, 3:54 pm, Stewart Robert Hinsley
wrote:
In message
, Len
Wood writes
How are we do this?
How much warmer than average and for how long?
Can I suggest:
Max daily temp 2 degrees C above average any time in the autumn
months of Sep. to Nov.
and for more than one day.
I suggest a prolonged period (1 week) of warm and bright weather. I'd
tend to exclude early September (just the tail end of summer) and late
November (difficult to get the warmth and brightness that late).
The average (over last 10 years) max for Wembury for the last week of
September
is 17.5C.
So I will be looking for 19.5C.
The forecast discombobulated upper trough, cutting off the N. Atlantic
air, and giving a SE wind is the business, and is likely to easily
give max temps of 20C or more.
The last time we had such conditions around here in the last week of
September
was in 1985.
Plymouth Mt Batten recorded
26 Sep 21.2C
27 Sep 21.4C
28 Sep 20.3C
29 Sep 20.7C
30 Sep 21.0C
Indian Summers have occurred in Wembury in the third week of Sep.
1998
and Sep. 2006 with a max in excess of 20C for 3 or 4 days in a row.
Len Wood
Wembury, SW Devon , 83 m asl
--
alias Ernest Major- Hide quoted text -
- Show quoted text -
I was wondering about start and end dates too.
The average max for the last week in Nov in Wembury is 10.3C
so a few days with max of 12.3 C would count as an Indian summer?
Clearly not.
Perhaps an Indian summer has to have max of 20C and is more tied with
the synoptics which can bring air from a still warm continent.
So October would be the latest for such a delight.
Len
Wembury
I'd also go for "not before the equinox" also.
Jim.
--
Bournemouth Weather readings online:http://www.g0ofe.com/weather
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I think we have a consensus here that an Indian Summer in the UK can
only occur after the equinox.
As I wrote earlier, I wouldn't say that Indian Summer is appropriate to
describe an early September warm spell. But restricting it to
occurrences after the equinox might be too much - would you say that a
spell running from the 18th to the 28th September was not an Indian
Summer.
A possible rule of thumb is that an Indian Summer ends after the
equinox.
This is good science sense as the solar receipt is an important
controlling factor.
We have had, and are having, an Indian Summer here in Wembury.
Yesterday's max 23.0C, today's 22.8C.
Average for the last week of Sep. is 17.5C
So we are 5 degC above average. Perhaps my quailfying temp of 2 degC
above average is too low.
Anyone any thoughts on this?
Len Wood
Wembury, SW Devon, 83 m asl
--
Stewart Robert Hinsley