Summary
for September 2006
==========================
HEADLINE:
EXCEPTIONALLY WARM. DRY UNTIL 12TH, THEN SHORT-PERIOD DOWNPOURS
(last
updated: 01/0900 OCTOBER)
Location:
Tawfield/Wooden Hill area of SW
Bracknell, Berkshire, UK
Altitude
80 m (other location details see elsewhere on web site.)
(temperatures
[standard screen] degC; rainfall/melted snowfall mm; snow depths cm; )
=================================
TEMPERATURES
ETC.
Highest
day maximum (date):... 28.8(11)
Highest
24hr maximum (date):.. 28.8(11)
Lowest
night minimum (date):... 07.0(08)
Lowest
24hr minimum (date):... 07.0(08)
Lowest
overnight grass minimum (date):... 03.6(08)
[
number of days grass minimum < 0degC: ... 00 ]
[
Lowest day maximum (date):... 17.4(22)]
[ Highest
night minimum (date):... 18.2(05)]
A. Mean
Day (09-18Z) maximum: ... 21.7
A. Mean
Night (18-09Z) minimum: ... 14.0
A. Mean
of Day Max & Night min: ... 17.9
B. Mean
24hr maximum:... 21.7 [+4.0 anomaly on
eLTA of 17.7degC]
B. Mean
24hr minimum:... 13.9 [+3.1 anomaly on
eLTA of 10.8degC]
B. Mean
of 24hr max & min:... 17.8 [+3.6 anomaly on eLTA of 14.2degC]
(data
below relate to 24 hr day beginning 09Z on date given)
Nr of
days minimum at 09UTC <0.0degC:00
Nr of
days maximum at 09UTC >=21degC:14
Nr of
days maximum at 09UTC >=25degC:06
Nr of
days maximum at 09UTC >=30degC:00
(Notes
relating to temperature & allied observations:
see
note at bottom relating to exceptional monthly mean temperature)
=================================
PRECIPITATION
(PPN/mm)
Total
rainfall/melted snow etc:... 86.2 [129%
of eLTA of 67mm]
Highest
24hr total:............... 22.8(22)
No.
days PPN total >= 0.2:13
No.
days PPN total >= 1.0:10
No.
days PPN total >=10.0:03
No.
days PPN total >=25.0:00
(Notes
relating to precipitation & allied observations:
1st
(credited to August rainfall): short period r between 0415 & 0430Z, ir(few
drops/medium-level) thereafter until ~10Z;
2nd:
ir(mainly light) from 0630Z, with ir/id (all mostly light) for the rest of the
day and continuing through the night 2nd/3rd, until 03/1000Z;
6th:
ir(few drops)~1650Z from medium-level unstable cloud;
11th/12th:
r(R) 11/2315 - 0010Z (accompanied by slight thunder – see below);
12th:
ir(slight) PM, mostly few droplets at a time, but short-period more persistent
rain ~1515/1530Z;
12th/13th:
r(slight)/r from late PM to early hours;
13th/14th:
ir(slight) from 1710Z: r/R (accompanied by thunder – see below) from 2145 -
0015Z. Further periods r(R) thereafter (not thundery) until ~05Z;
14th:
ir(very light) AM;
15th:
continuous r(slight ocnl moderate) 06-0830Z, then intermittent light until
~0915Z;
18th/19th:
ir(very light) late PM/around midnight;
20th:
pr(very slight) 0900-0910Z;
21st:
tl(slight/one distant rumble) 2020Z, as r set in suddenly – rain ceased for a
short while until 2055Z.
21st/22nd:
following above event, slight to moderate rain much of night from just before
midnight until ~0530Z;
22nd:
ir(slight) from 0850Z, becoming persistent by 0905Z, then r(R) until ~1410Z, then
slight until ceasing by 1435Z. Two periods of notably heavy rainfall - (a)
around 0920Z & (b) extended periods (tempo "torrential") between
1245 & 1315Z, this latter phase producing a couple of rumbles of thunder;
24th:
r(slight/moderate) 0530-0655Z, with period R 0615-0640Z;
25th:
ir(slight) 05-0830Z; pr(slight)/r 1505Z – 1655Z, with tl(slight/few rumbles)
between 1622 & 1650Z;
27th/28th:
ir(slight) 23-01Z;
28th:
rd(slight, tempo moderate) 0730-0830Z: pr(slight) until ~13Z; r(R) latter half
of evening;
29th:
ir(slight) from early hours –> pr(slight) off and on through morning &
afternoon, with period r/R between 1420 & 1445Z;
29th/30th:
ocnl r, mainly around 02Z & 06Z;
30th:
slight (isolate moderate) rain showers from 1145Z, with tl(two-rumbles) 1358Z,
with further ocnl rain evening & overnight 30th/1st October, rainfall to
09Z credited to this month's rainfall;
=================================
OTHER
TOTALS
Number
of days thunder heard: (dates).. 06 (11,13,21,22,25,30)
Number
of days hail < 0.5cm diameter:.. 00
Number
of days hail >=0.5cm diameter:.. 00
Number
of days snow/rain & snow:....... 00
Number
of days snow lying at 09UTC:.... 00
Deepest
snow cover (date,s):........... -
Number
of days fog (visibility < 1km @ 09UTC).. 00
=================================
Additional
comments on the weather in September, 2006
2nd:
wind (SSW/SW) ocnl F6 during afternoon – with short periods close to F7
~mid-afternoon. Much tree debris in garden!
3rd:
wind (WSW) ocnl F6, temporary bursts to F7, from late morning to mid-afternoon.
10th:
period mist/very low cloud ~0500Z – 0800Z, with f 0515-0735Z.
12th:
after a misty night (vis ~2-3km) after the earlier thundery rain, f 0645-0815Z.
21st:
F5, ocnl F6 during early / mid-afternoon.
22nd: for
the partial rain-day 09-18Z, with 22.6mm over this period, probably the wettest
such period here for at least 3 years.
22nd/23rd:
a combination of heavy dew & wet fog (late in the night), gave a measured
0.2 mm at 09Z on the 23rd.
25th: f
up to ~0830Z (after period of light / intermittent rain).
25th/26th:
heavy dew overnight (after rain earlier), gave 0.1mm in gauge 09Z on the 26th.
[thunder]
(Total
number of days thunder heard this year [so far] = 21: the estimated local
average of such days for the *whole year* is 15.)
11th:
tl(slight/peak discharge rate 1 per 3 or 4 mins) between 2320 & 2355Z,
mainly mid-level activity/sheet lightning; accompanied by moderate,
occasionally heavy rainfall.
13th:
tl(slight, short period moderate) between 2215Z & 2310Z (last rumble heard
then): peak discharge rate 1 per 30-45 mins, but mostly 1 per 2 to 4 mins.
21st:
single rumble of distant thunder 2020Z (as local rain started abruptly).
22nd:
as an extended period of heavy (torrential!) rain set in (lasting from 1245
until 1315Z), a couple of muffled rumbles of thunder in the vicinity.
25th:
tl(slight / few rumbles ex-CC/IC) between 1622 & 1650Z; further t(thunder
heard in distance / to east) from ~1745Z, not heard after 1830Z.
30th:
tl(slight / two-rumbles) ~ 1358Z, with slight rain.
[snow]
NIL
...
these data can also be viewed at:-
http://homepage.ntlworld.com/booty.weather/metinfo/wxdata/climintro.htm
Tn
Tx Tg RR
Tn Tx RR
RR24hr Remark code (below)
(09Z) (09Z) (09Z)(18-09Z) (18Z) (18Z)
(09-18Z) (from 09Z today)
01 14.9
20.9 13.4 tr
16.6 21.6 tr
00.1 -
02 14.4
19.6 13.2 00.1
15.9 19.0 tr
00.3 A
03 17.3
20.2 17.3 00.3
20.2 25.3 tr
tr B
04 14.3
21.3 12.2 -
18.1 24.4 -
- C
05 18.2
22.0 16.4 -
20.7 25.6 -
-
06 17.1
23.3 15.3 -
20.1 26.3 tr
tr
07 12.0
23.5 08.4 -
15.6 20.6 -
-
08 07.0
18.5 03.6 -
13.9 20.5 -
-
09 09.7
18.4 07.0 -
14.9 21.8 -
-
10 09.3
18.8 05.6 -
15.5 25.4 -
-
11 12.4
23.1 09.6 -
18.4 28.8 -
08.5
12 15.0
23.1 13.7 08.5
16.2 20.0 tr
02.9
13 16.0
19.1 14.5 02.9
18.2 22.9 tr
20.2
14 16.6
20.1 16.0 20.2
18.2 19.7 tr
01.4
15 14.6
18.2 13.2 01.4
14.8 21.6 tr
tr D
16 16.1
19.5 14.7 -
16.6 20.6 -
-
17 15.4
19.4 14.1 -
17.4 22.9 -
-
18 14.4
20.5 12.0 -
16.6 20.5 -
tr
19 11.9
17.3 10.1 tr
14.7 19.7 -
-
20 11.8
17.0 09.6 -
16.7 21.5 tr
tr
21 16.6
19.9 14.0 -
19.9 26.1 -
04.2
22 15.6
24.1 14.9 04.2
16.1 17.4 22.6
22.8
23 13.0
16.3 10.0 00.2
15.0 21.3 -
11.6 EF
24 15.1
19.2 13.4 11.6
15.9 20.5 -
tr
25 14.1
17.7 12.5 tr
15.6 20.6 03.4
03.5
26 11.5
17.2 08.8 00.1
14.5 19.2 -
- G
27 12.1
16.8 09.6 -
15.2 19.7 -
00.2 H
28 16.7
17.5 15.1 00.2
17.4 20.0 tr
05.5
29 15.5
17.6 14.1 05.5
16.4 18.6 02.2
04.3
30 12.0
16.4 10.6 02.1
14.6 18.6 00.5
00.7
Readings
taken at 0900 and 1800 UTC. Where the NIGHT maximum or DAY minimum are
significantly different from 24hr values, this will be noted in the listing
against a 'Remarks' letter. There are two mean temperatures shown: the first is
the mean of the average day maximum and average night minimum (A), and the
second is the average of the 24hr maximum and 24hr minimum (B) .. the anomalies
are shown for this latter figure from 1971-2000 estimated Long Term Averages.
Rainfall is credited to the 24hr day beginning 0900 UTC.
Remarks:
A. day
min.(15.9), also 24hr min 3rd, occurred 02/09Z
B.
night max.(20.2), also 24hr max 2nd, occurred 03/09Z
C. day
min.(18.1), also 24hr min 5th, occurred 04/09Z
D. day
min.(14.8), also 24hr min 16th, occurred 15/09Z
E.
measured 0.2 mm at 09Z due to fe(wet fog) & heavy dew
F. day
min.(15.0), also 24hr min 24th, occurred 23/09Z
G.
measured 0.1 mm at 09Z due to heavy dew overnight
H. day
min.(15.2), also 24hr min 28th, occurred 27/09Z
--------------------------------------------------------------------
Number
of occasions (24hr periods) THIS YEAR (2006)
maximum
temperature >= 21degC (70degF) = 92
minimum
temperature >= 16degC (61degF) = 24
Rolling
12 month temperature anomaly: +1.0 (was +0.9 end last month)
Rolling
12 month rainfall: 91% of eLTA (was 86% end last month)
Rolling
24 month rainfall: 86% of eLTA (was 83% end last month)
--------------------------------------------------------------------
Total rainfall
for this year (2006) so far: 435.8 mm, representing 88% of the 'average' that
we should have by the end of September (493mm).
--------------------------------------------------------------------
The
mean (24hr) temperature of 17.8degC places this September (2006) as the warmest
such-named month in a composite local series beginning 1971. It was also
warmer, by a margin of 0.3degC, than August: it is important to note that
August 2006 was NOT a cold month – that month's anomaly was +0.3degC, so the
'excess' heat during September was even more remarkable.
This
has been the wettest September since that of 2000. There have been 10 wetter
Septembers in a composite record from 1971.