Summary for October 2004

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HEADLINE: UNSETTLED/CYCLONIC: FREQUENT RAINFALL. ABOVE-AVERAGE TEMPERATURES

(last updated: 29/1600 NOVEMBER)

[absence 23/10Z to 24/16Z: intervening data estimated / interpolated]

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; )

Readings taken at 0900 and 1800 UTC. Where the NIGHT maximum

or DAY minimum are significantly different from figures hereunder, this will be noted in the accompanying text summary. There are now two mean daily 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 .. as kept formerly) .. 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.

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TEMPERATURES ETC.

Highest day maximum (date):... 16.4(02)

Highest 24hr maximum (date):.. 16.4(02)

Lowest night minimum (date):... 05.1(08)

Lowest 24hr minimum (date):... 05.1(08)

Lowest overnight grass minimum (date):... 03.1(08)

[ number of days grass minimum < 0degC: ... 00 ]

[ Lowest day maximum (date):... 10.2(16)]

[ Highest night minimum (date):... 13.4(24)]

A. Mean Day (09-18Z) maximum: ... 14.0

A. Mean Night (18-09Z) minimum: ... 08.5

A. Mean of Day Max & Night min: ... 11.3

B. Mean 24hr maximum:... 14.0

B. Mean 24hr minimum:... 08.4

B. Mean of 24hr max & min:... 11.2 [+0.7 anomaly on eLTA of 10.5degC/CORRECTED FIGURE]

(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:00

Nr of days maximum at 09UTC >=25degC:00

Nr of days maximum at 09UTC >=30degC:00

(Notes relating to temperature & allied observations:

none)

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PRECIPITATION (PPN/mm)

Total rainfall/melted snow etc:...124.8 [166% of eLTA of 75mm]

Highest 24hr total:............... 20.2(20)

No. days PPN total >= 0.2:21

No. days PPN total >= 1.0:16

No. days PPN total >=10.0:04

No. days PPN total >=25.0:00

(Notes relating to precipitation & allied observations:

1st: ir(slight) ~1230Z/Sc mammatus; r(slight)/r 1745Z - 2015Z ;

2nd: pr(slight) much of day, with pr 1610-1620Z;

2nd/3rd: r(slight)/r late evening & early hours;

3rd: ir(slight) from 11Z, with dr(slight)/r(slight), ocnl r 1215-1330Z;

4th: r(R) from ~00Z to 06Z, then idr(slight)/ocnl r(slight) until ~1015Z;

5th: ir(slight) ~0830Z; pr(slight) through day;

6th: pr(slight) through day, with ph(<5mm dia)rq ~ 1140Z; pr 1840-1850Z;

8th: pr(slight/very) ~10Z;

12th: r(slight)/r from at least 0430Z; dr(slight) by 09Z, this continuing thereafter much of day, with ocnl r(slight), & ocnl r from 16Z: rain becoming lighter/dying out evening;

13th: r(slight), ocnl r 1045-1430Z;

14th: ocnl r(R) from ~01Z: tl(slight)r ~0514Z [see below]: rain csd by ~ 0845Z; pr(1450-1500Z), with light showers other times/non-sig;

14th/15th: ocnl dr(slight)/r overnight, csd by ~0830Z;

15th: pr(slight) through day, ocnl pr PM;

15th/16th: ocnl r(slight)/r overnight . . . csd by 0830Z;

16th: further idr(slight) morning: pr(slight) afternoon, with pr/R 1320-1340Z providing bulk of 4.8mm 09-18Z;

16th/17th: ocnl r(mainly slight) overnight;

17th: pr(slight) through afternoon;

19th: r(slight) 0645-0850Z; ocnl r(slight) 09-17Z;

19th/20th: r(slight)/r overnight, becmg d(slight) by 07Z;

20th: ocnl d(slight) 09Z-14Z: 1615Z onwards, pr(slight)/pr; r(R) 21-23Z, with short period intense rainfall ~22Z (see comment below);

21st: pr(slight) ~ 0615Z; pr(v.light) afternoon;

22nd: id(slight) 18Z, ocnl r(mainly slight) overnight 22nd/23rd;

23rd: r(slight) from ~07Z: wet (mix of dr/r/isol R) through day & evening;

23rd/24th: dr(slight)/r(slight)/r dying out by ~24/0100Z;

24th: pr(slight) afternoon, with pr/tl(slight)r(slight) 1640Z-1715Z; further pr early evening;

25th: pr(slight) until early afternoon;

27th: r(slight) from 1345Z, tempo r late afternoon;

27th/28th: pr/r overnight until ~08Z;

28th: pr(slight/very) late AM to early PM; r(slight)/r from 1703Z, r/R from 1745Z, back to slight 1810Z, csd by 1940Z;

28th/29th: further pr/r(slight ocnl moderate) overnight;

29th/30th: ocnl r overnight;)

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OTHER TOTALS

Number of days thunder heard: (dates).. 02 (14,24)

Number of days hail < 0.5cm diameter:.. 01

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

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Additional comments on the weather in October, 2004

2nd: screen cleaned of contamination of fine, black or dark-grey powder / dust inside which had built up over the past 4 or 5 days;

6th: hail circa 1140Z very small element in moderate rain shower: diameter circa 3mm for less than one minute;

10th: strong East wind much of day;

14th: tl(slight/single CG discharge) ~0514Z - vivid, close-by ground stroke, followed by extended 'rumble' indicating convoluted lightning path;

20th: intense rainfall circa 22Z: local reports of single lightning discharge & thunder, but none observed here - possibly missed?

24th: tl(slight)r(slight) ~1706Z - single CC discharge amongst mix of slight/moderate rain showers between 1640-1715Z;

24th/25th: wind strong/gusty (Bft 6, ocnl 7) overnight;

... 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 08.3 14.9 06.3 tr(W) 12.0 15.9 tr 01.5 W=dew

02 08.7 14.0 07.2 01.5 12.0 16.4 02.3 04.9

03 09.1 12.6 07.4 02.6 12.5 14.8 02.9 15.7 A

04 12.0 15.5 11.3 12.8 11.4 15.0 tr tr BC

05 07.5 11.8 05.2 tr 11.7 16.1 00.4 00.4

06 07.8 11.8 06.6 - 10.7 14.6 02.9 04.0

07 06.8 10.7 04.8 01.1 09.6 14.4 - -

08 05.1 10.2 03.1 - 10.0 14.6 tr tr

09 07.2 11.3 06.0 - 10.3 14.3 - -

10 08.7 11.4 07.6 - 10.9 14.2 - -

11 06.8 11.7 04.6 - 10.7 13.5 - 02.4

12 09.8 11.3 (09.2) 02.4 10.7 13.1 03.0 03.1 D

13 08.6 13.2 06.9 00.1 10.4 14.0 02.5 19.3 E

14 08.3 10.4 06.6 16.8 08.5 12.4 02.2 04.3

15 07.2 08.4 06.7 02.1 08.1 10.5 00.4 03.0

16 07.5 09.0 07.1 02.6 07.9 10.2 04.8 05.8

17 05.5 08.3 04.6 01.0 08.2 11.5 00.2 00.2 F

18 07.0 09.5 06.0 tr(W) 08.1 13.0 - 00.6 W=dew

19 05.3 08.2 03.3 00.6 07.6 13.1 00.6 08.0 G

20 12.2 13.1 11.0 07.4 13.1 15.8 01.8 20.2 H

21 07.7 15.0 06.4 18.4 10.3 14.3 tr tr I

22 10.8 14.0 09.5 - 14.0 15.5 tr 01.1

23 13.3 15.4 12.7 01.1 (14.6) 16.3 (09.4) 17.2

24 13.4 xx.x 12.0 (07.8) xx.x (15.9) 00.4 00.7

25 10.8 13.6 09.8 00.3 09.8 13.3 tr tr

26 05.3 09.7 03.2 - 08.4 12.6 - tr

27 06.0 09.4 04.4 tr(W) 09.3 11.7 00.9 06.1 W=dew

28 09.3 12.4 08.8 05.2 11.2 14.5 02.7 05.4 J

29 09.3 11.6 08.1 02.7 11.5 13.9 - 00.9 K

30 09.9 12.2 08.7 00.9 11.0 15.0 - -

31 08.8 12.7 06.0 - 10.0 12.5 - -

Remarks:

A. night max. 3rd (12.6) occurred 03/09Z

B. night min. 4th (12.0) occurred 04/09Z: air-mass change/cold front 08-09Z

C. night max. 4th (15.5) was also 24hr max for 3rd/4th.

D. grass min. 12th(9.2) estimated: stuck index.

E. night max. 13th(13.2), also 24hr max 12th/13th, occurred 12th eve.

F. night max. 17th(8.3) occurred 17/09Z

G. day min. 19th(7.6) was also 24hr min credited to 20th.

H. night max. 20th(13.1), also 24hr max 19th/20th, occurred 20/09Z

I. day min. 21st(10.3) also 24hr min 21st/22nd

J. night max. 28th(12.4), also 24hr max 27th/28th occurred 28/09Z

K. night max. 29th(11.6) occurred 29/09Z

Number of occasions (24hr periods) THIS YEAR (2004)

maximum temperature >= 21degC (70degF) = 80

minimum temperature >= 16degC (61degF) = 13

Some comments upon October 2004 rainfall and temperatures:

Rainfall:

The total rainfall for this location was: 124.8mm[166% of eLTA 1971-2000]

Our records begin only in 2000, but this month's figure was beaten by that of 2001 (129mm), and easily exceeded by 2000 (178mm).

In a composite Easthampstead Park/Tawfield [adjusted] record (1971-2003), the total rainfall for October 2004 was equalled or exceeded on 7 occasions (out of the 33yr): 1976, 1982, 1987, 1993, 1998, 2000 & 2001.

Very few problems with flooding etc., round here due to the dry nature of September.

Temperature:

The anomaly (based on 24hr max/min) was +0.7degC

Until the middle of the month, daytime maxima were declining well, and helping to drag the overall mean down such that had the trend continued, we could have ended up with an anomaly close to zero (though probably still on the positive side). Thereafter, an abrupt recovery in maxima (second warmest day of month 23rd = 16.3degC), coupled with mainly high night minima, and the overall anomaly ended up as above. No ground frosts or air frosts recorded.

Only one month this year (so far) has had mean temperature below average (July), and that was marginal (-0.3); the others all above average, and with the exception of March (+0.0) & this month (+0.7), they have been *significantly* above average (i.e. >= +1C).

The running anomaly for this year (2004) = +1.0C

The 12-month rolling anomaly = +1.0C