The monthly circulation indices -- westerliness,
southerliness, and anticyclonicity -- for July
1873-2003 can now be found on
www.climate-uk.com Just follow the link
near the bottom of the page.

The charts have some quite startling features,
including a large an abrupt switch between
'northerly' Julys between the 1950s and early
1980s, and 'southerly' Julys since.

There are signs that the present 'southerly'
episode may well have passed its peak.

Less dramatic but still remarkable is the long,
slow decline in the 'westerliness' of July over
the last threequarters of a century.

These elements, together with gentler
variations in the anticlonicity index may well
explain /some/ of the large variations in
rainfall and temperature during this
particular month over the decades.

Philip Eden

Thanks for that, Philip. The decline in westerliness is probably the
most important factor in the decline in July rainfall. In the 21 years I have
been recording (SE England) July is the driest month of the year. This was
certainly not the case 50 years ago.
There are a few errors, if you don't mind me saying. The charts for
Westerliness and Anticyclonicity have scales that are 10 times too large, and
the extremes of each type on the right of the page is headed "June" rather than
"July".

Tudor Hughes, Warlingham, Surrey.

"TudorHgh" wrote in message
...
There are a few errors, if you don't mind me saying. The
charts for
Westerliness and Anticyclonicity have scales that are 10 times too
large,

All three have ordinates ostensibly in mbar/10 (of course the
directional
ones are differences and might therefore carry the legend "mbar/10
per
10 deg latitude/longitude" and the anticylonicity one is absolute)
but they
are just indices ... that's why I didn't change them from the my
spreadsheet where the decimal points are left out. However, I did
not
make that clear in the commentary.

and
the extremes of each type on the right of the page is headed
"June" rather than
"July".

Thankyou. That's what comes of using last month's as a template.

Philip Eden

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
...
The monthly circulation indices -- westerliness,
southerliness, and anticyclonicity -- for July
1873-2003 can now be found on
www.climate-uk.com Just follow the link
near the bottom of the page.

The charts have some quite startling features,
including a large an abrupt switch between
'northerly' Julys between the 1950s and early
1980s, and 'southerly' Julys since.

There are signs that the present 'southerly'
episode may well have passed its peak.

Less dramatic but still remarkable is the long,
slow decline in the 'westerliness' of July over
the last threequarters of a century.

These elements, together with gentler
variations in the anticlonicity index may well
explain /some/ of the large variations in
rainfall and temperature during this
particular month over the decades.

Philip Eden



Blimey Philip. Were you a polka player in a previous life?

"Lawrence" wrote in message
...


Blimey Philip. Were you a polka player in a previous life?

You think I'm dotty, Lawrence?

pe

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
...

"Lawrence" wrote in message
...


Blimey Philip. Were you a polka player in a previous life?

You think I'm dotty, Lawrence?

pe


Its just that " Itsy Bitsy Teenie Weenie yellow bikini"- it has me
confused?