The present exceptionally weak phase of the Arctic
Oscillation appears to have been the dominant influence
on the synoptic characteristics of the summer quarter
(J,J,A) of 2009.

Mean sea-level pressure and anomaly charts can be found at

http://www.climate-uk.com/monpre/09QQ.htm

The mean sea-level pressure field shows the Icelandic
Low displaced well south of its normal location at
56N 20W, central pressure 1009mbar. The Azores
High is at normal intensity (1022mbar) slightly SW of
its normal position. The net effect is to transfer and squeeze
the strongest surface flow across the Atlantic to between
latitudes 40 and 50degN instead of its normal position
between lats 45 and 60degN. There is an anomalous
area of high pressure, 1020mbar, centred over Greenland.
The mean surface flow over the British Isles is SW-ly
instead of the more usual W-ly.

The mean anomaly field is dominated by two centres:
-7mbar off SW Ireland (at 51N 19W)
+8mbar over central/NE Greenland
The anomalous flow over the British Isles is SSW-ly over
England, Wales and Ireland, and SSE-ly over Scotland.
Mean anomaly ranges from -1.5mbar in Sussex and Kent
to -5mbar on the west coast of Ireland. The 'southerliness'
index has only been exceeded in four summers in 137
years of records: in 1947, 1950, 1994 and 2003.

CET (Manley): 15.93°C (+0.3 degC wrt 1971-2000)
E&W Rainfall: 252.3mm (128% wrt 1971-2000)
E&W Sunshine: 589.0h (100% wrt 1971-2000)

CScotT: 14.76°C (+0.7 degC)
Scot Rainfall: 300.2mm (150%)
Scot Sunshine: 542.6h (114%)

NIT: 14.78°C (+0.5 degC)
NI Rainfall: 307.8mm (161%)
NI Sunshine: 567.1h (117%)

(c) Philip Eden

"Philip Eden" philipATweatherHYPHENukDOTcom wrote :

The present exceptionally weak phase of the Arctic
Oscillation appears to have been the dominant influence
on the synoptic characteristics of the summer quarter
(J,J,A) of 2009.

Mean sea-level pressure and anomaly charts can be found at

http://www.climate-uk.com/monpre/09QQ.htm

The mean sea-level pressure field shows the Icelandic
Low displaced well south of its normal location at
56N 20W, central pressure 1009mbar. The Azores
High is at normal intensity (1022mbar) slightly SW of
its normal position. The net effect is to transfer and squeeze
the strongest surface flow across the Atlantic to between
latitudes 40 and 50degN instead of its normal position
between lats 45 and 60degN. There is an anomalous
area of high pressure, 1020mbar, centred over Greenland.
The mean surface flow over the British Isles is SW-ly
instead of the more usual W-ly.

The mean anomaly field is dominated by two centres:
-7mbar off SW Ireland (at 51N 19W)
+8mbar over central/NE Greenland
The anomalous flow over the British Isles is SSW-ly over
England, Wales and Ireland, and SSE-ly over Scotland.
Mean anomaly ranges from -1.5mbar in Sussex and Kent
to -5mbar on the west coast of Ireland. The 'southerliness'
index has only been exceeded in four summers in 137
years of records: in 1947, 1950, 1994 and 2003.

CET (Manley): 15.93°C (+0.3 degC wrt 1971-2000)
E&W Rainfall: 252.3mm (128% wrt 1971-2000)
E&W Sunshine: 589.0h (100% wrt 1971-2000)

CScotT: 14.76°C (+0.7 degC)
Scot Rainfall: 300.2mm (150%)
Scot Sunshine: 542.6h (114%)

NIT: 14.78°C (+0.5 degC)
NI Rainfall: 307.8mm (161%)
NI Sunshine: 567.1h (117%)

(c) Philip Eden
I've not finalised my data for the summer quarter (JJA).

Highest mean maxes we
23.5 Canterbury
23.1 Heathrow
22.9 Cambridge
22.9 Broadness (Kent)
22.8 St James's Park
(also 23.0 Clerkenwell [rooftop site])

Lowest mean maxes (excluding sites above 300m amsl) we
14.4 Fair Isle
14.8 Lerwick (Shetland)
15.3 Baltasound (Shetland)
15.7 Wick (Caithness)


Biggest +ive anomalies were +2.3degC at Marham
(Norfolk) and Charlwood (Surrey)
Biggest -ive anomalies were -0.8degC at Aberdaron
(Caernarfon) and -0.7degC at L.Vyrnwy (Montgomery)
[some of these anomalies appear to be outliers, suggesting
a change of site which I'm not aware of, or an error in
calculation of averages]

Highest mean mins we
14.5 at St Cath's Point (IoW)
14.2 at Lee-on-Solent (Hants)
14.2 at Eastbourne
14.1 at Portland (Dorset)
(also 14.8 on that roof at Clerkenwell)

Lowest mean mins (excluding sites above 300m amsl) we
8.0 at Braemar (Aberdeenshire)
8.4 at Loch Glascarnoch (Wester Ross)
8.6 at Dalwhinnie (Inverness-shire)
8.7 at Kinbrace and Altnaharra (both Sutherland)

Biggest mean min anomalies we
+2.4degC at Pembrey Sands (Carmarthen)
+2.2degC at St Angelo (Co Fermanagh)
-1.0degC at Topcliffe (N Yorks)
-1.0degC at Glenanne (Co Armagh)
[ditto comments above]

Highest rainfall:
706.0mm at Inveruglas (Dunbartonshire)
696.5mm at Eskdalemuir (Dumfriesshire)
661.7mm at Capel Curig (Snowdonia)
637.0mm at Shap (Cumbria)
622.6mm at Valentia (Irish Rep)
588.3mm at Tyndrum (old Perthshire)
574.6mm at Cluanie Lodge (Wester Ross)
560.7mm at Liscombe (Exmoor)

Highest rainfall percentages wrt 1971-2000:
299 St Mary's (Isles of Scilly)
296 Valentia
251 Eskdalemuir
233 Cork
212 Bishopton (Renfrewshire)

Lowest rainfall:
84.7mm at Canterbury
91.9mm at Shoeburyness (Essex)
96.6mm at Brooms Barn (Suffolk)
100.9mm at East Malling (Kent)
102.7mm at Andrewsfield (Essex)

Lowest rainfall percentages:
78 at Andrewsfield
79 at Odiham (Hants)
79 Middle Wallop (Hants)
80 at Shoeburyness

Highest sunshine totals:
770.4h at Eastbourne
750.8h at Manston (Kent)
699.6h at St Helier (Jersey)
676.8h at St Peter Port (Guernsey)
649.6h at Weymouth

Highest sunshine percentages:
143 Fair Isle
127 Malin Head (Irish Rep)
122 Tiree
118 Lerwick
118 Manston

Lowest sunshine totals:
333.4h at Eskdalemuir
344.4h at Kinlochewe (Wester Ross)
393.6h at Durham
406.6h at Braemar
412.1h at Dyce (Aberdeen)
419.0h at Woodford (Gtr Manchester)

Lowest sunshine percentages:
74 at Eskdalemuir
78 at St Athan (Glamorgan)
81 at Yeovilton (Somerset)
82 at Watnall (Notts)
82 at Woodford
83 at Shawbury (Salop)

(c) Philip Eden

SNIP

Highest rainfall percentages wrt 1971-2000:
299 *St Mary's (Isles of Scilly)
296 *Valentia
251 *Eskdalemuir
233 *Cork
212 *Bishopton (Renfrewshire)

(c) Philip Eden- Hide quoted text -


How does the Scilly rainfall anomaly compare to other sites in
Cornwall/Devon?

I ask because there is no doubt that Scilly does regularly report
0.4mm/0.6mm when it appears to have been totally dry, and I'm now
having doubts over the many occasions when the rainfall has been very
large compared to west Cornwall.

The % of normal in Penzance for JJA is 154%, which is very different
to Scilly's 299%, and I have recorded a number of notable rainfall
events, notably 29.7mm on 11/7, 51.8mm on 16/7, 48.4mm fell in the 24
hours commencing 14:30 on 28th.

I'll try and get the data from St. Martins.

Graham
Penzance

On Tue, 8 Sep 2009 at 17:08:50, Philip Eden
wrote in uk.sci.weather :

Lowest mean mins (excluding sites above 300m amsl) we
8.0 at Braemar (Aberdeenshire)

Surely Braemar *is* over 300m?

In T.J.Chandler's 'Climate Of The British Isles', the table on page 121
lists it as 339m.

Admittedly the station might have moved in the meantime, but still...
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)

"Graham Easterling" wrote in message
...
SNIP

Highest rainfall percentages wrt 1971-2000:
299 St Mary's (Isles of Scilly)
296 Valentia
251 Eskdalemuir
233 Cork
212 Bishopton (Renfrewshire)

(c) Philip Eden- Hide quoted text -


: How does the Scilly rainfall anomaly compare to other sites in
: Cornwall/Devon?
:
: I ask because there is no doubt that Scilly does regularly report
: 0.4mm/0.6mm when it appears to have been totally dry, and I'm now
: having doubts over the many occasions when the rainfall has been very
: large compared to west Cornwall.
:
: The % of normal in Penzance for JJA is 154%, which is very different
: to Scilly's 299%, and I have recorded a number of notable rainfall
: events, notably 29.7mm on 11/7, 51.8mm on 16/7, 48.4mm fell in the 24
: hours commencing 14:30 on 28th.
:
: I'll try and get the data from St. Martins.

You may well be right, Graham. Most of the large totals are also
larger than those recorded on the mainland. I think it's quite
reasonable to be suspicious. I'll be interested to see what you
come up with elsewhere on the islands. All the other percentages
in Cornwall are between 140 and 160.

Philip

"Paul Hyett" wrote :
On Tue, 8 Sep 2009 at 17:08:50, Philip Eden wrote in uk.sci.weather :

Lowest mean mins (excluding sites above 300m amsl) we
8.0 at Braemar (Aberdeenshire)

Surely Braemar *is* over 300m?

In T.J.Chandler's 'Climate Of The British Isles', the table on page 121
lists it as 339m.

Admittedly the station might have moved in the meantime, but still...
--
Clever clogs. I meant excluding sites above 340m, of course.

Philip

In article ,
Philip Eden writes:
I've not finalised my data for the summer quarter (JJA).
snip

I suspect that should have read "now".
--
John Hall "Do you have cornflakes in America?"
"Well, actually, they're American."
"So what brings you to Britain then if you have cornflakes already?"
Bill Bryson: "Notes from a Small Island"

On Tue, 8 Sep 2009 at 18:20:16, Philip Eden
wrote in uk.sci.weather :

"Paul Hyett" wrote :
On Tue, 8 Sep 2009 at 17:08:50, Philip Eden wrote in uk.sci.weather :

Lowest mean mins (excluding sites above 300m amsl) we
8.0 at Braemar (Aberdeenshire)

Surely Braemar *is* over 300m?

In T.J.Chandler's 'Climate Of The British Isles', the table on page 121
lists it as 339m.

Admittedly the station might have moved in the meantime, but still...
--
Clever clogs. I meant excluding sites above 340m, of course.

Grin.
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)