Summary for July 2004

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HEADLINE:CYCLONIC/COOL UNTIL 12TH THEN WARM & LARGELY DRY: HOT FINISH

(last updated: 29/1600 November)

 

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):... 28.8(29)

Highest 24hr maximum (date):.. 28.8(29)

 

Lowest night minimum  (date):... 08.5(06)

Lowest 24hr minimum   (date):... 08.5(06)

 

Lowest overnight grass minimum (date):... 07.1(05)

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

 

[ Lowest day maximum  (date):...   17.7(11)]

[ Highest night minimum (date):... 16.7(30)]

 

A. Mean Day (09-18Z) maximum:   ... 22.4

A. Mean Night (18-09Z) minimum: ... 12.3

A. Mean of Day Max & Night min: ... 17.3

 

B. Mean 24hr maximum:... 22.4

B. Mean 24hr minimum:... 12.3

B. Mean of 24hr max & min:... 17.3 [-0.3 anomaly on eLTA of 17.6degC/AMENDED]

 

(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:22

Nr of days maximum at 09UTC >=25degC:06

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

Notes relating to temperature & allied observations:

Although overall the mean temperature was just below average, the night minima ended up with an anomaly 0.0degC, and from 13th (incl.), the anomaly on day maxima was +1.1degC. The problem was the first 12 days of the month, when the average day maximum was 19.3degC (-3.9C), with one day 5.5C below average. It would have needed *markedly* above average temperatures for the rest of the month to offset this.

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PRECIPITATION (PPN/mm)

Total rainfall/melted snow etc:... 39.0  [87% of eLTA of 45mm]

Highest 24hr total:............... 19.4(07)

No. days PPN total >= 0.2:10

No. days PPN total >= 1.0:06

No. days PPN total >=10.0:01

No. days PPN total >=25.0:00

(Notes relating to precipitation & allied observations:

1st: pr(slight)/pr from late morning;

1st/2nd: (overnight) r(R), csd by ~0430Z;

2nd: frq pr(slight)/pr (&q) through day/early evening;

3rd: pr(slight) from ~0850Z until ~16Z;

4th: ir(v.light) ~0840Z; pr(slight)/pr 1812-1925Z;

6th: pr(slight) from 1745Z to 1810Z;

7th: r(slight)/r from 1401Z, ocnl R 1555-1615Z: rain started abruptly moderate at 1401Z: then r(slight/moderate) until ~23Z, with period R from ~2055Z to 2145Z;

8th: pr(slight), ocnl pr through day: t(1315Z/single rumble): r 1600-1620Z;

9th: pr (v.slight) mid-afternoon;

10th: pr(slight) from 0905Z through day (tr only): tl(slight)r(slight) ~1135Z; pr(R),q 2020-2035Z (2.2mm);

11th: ir(slight) until ~08Z; few pr(very light) 1145-13Z;

12th: r(slight)/r 0840-0855Z;

14th: r(slight)/dr(slight), ocnl r from 0535, csd by 0840Z;

15th: v.light d ~0745Z;

16th: r(slight)/dr(slight) early hours to ~08Z;

18th: r(slight), ocnl r from 0725Z, csd by 10Z; pr(slight) ~1725/1730Z;

20th: r(slight) 1910-1950Z;

21st: d(slight) ~ 0630Z; pr(very slight) early PM;

22nd: ir(very slight) mid-afternoon;

25th: ir(slight) 1320-1430Z & around 1645Z [evaporated quickly];

26th: id/r(slight) from ~0815Z to late morning, ocnl pr(slight);

29th: r(slight), short period r 22-23Z;

31st: ir(slight) 0835-0840Z (from apparently thin/broken Ac)

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OTHER TOTALS

Number of days thunder heard: (dates).. 02 (08,10)

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

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Additional comments on the weather in July, 2004

7th: ENE or NE wind F5/6, ocnl F7 (short-periods) from mid-morning to ~16Z;

8th: thunder heard (no PPN) ~ 1315Z;

10th: slight thunderstorm (with slight rain) ~1135Z;

26th: at 18Z observation hour, 2 oktas Ci, with trace Cc: of the cirrus, some elements were obviously ex-COTRA ('standard' condensation trails also in evidence - but rather short): these exhibited both castellatus properties (crenellations) - very vigorous allowing for the high altitude, and highly sheared fall-streaks (virga) in very tortuous patterns.

 

... 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  10.0  17.9  09.1  tr      15.8  19.4  00.6     04.5     -

02  11.5  16.6  10.9  03.9    13.9  18.2  02.2     02.2   A

03  10.7  16.3  09.9  tr      14.9  19.0  00.1     00.1

04  10.4  17.4  09.2  tr      15.4  18.3  -        02.2

05  08.8  17.4  07.1  02.2    16.1  21.7  -        -   

 

06  08.5  20.4  07.3  -       19.7  23.3  tr       tr 

07  11.7  20.5  10.5  tr      12.4  21.1  09.9     19.4

08  11.8  16.4  10.9  09.5    14.1  17.9  06.5     06.5   B

09  10.5  14.9  10.3  tr      14.0  18.4  tr       tr  

10  09.3  17.9  08.5  -       16.2  18.7  tr       02.2

 

11  10.5  16.2  10.1  02.2    14.7  17.7  tr       00.1

12  11.5  16.3  10.1  00.1    14.0  18.8  -        -   

13  08.7  17.5  07.2  -       17.4  21.9  -        00.9

14  12.6  19.1  12.2  00.9    14.7  21.8  -        tr     C

15  16.3  20.8  16.0  tr      18.7  24.1  -        00.4

 

16  16.6  22.7  16.2  00.4    17.6  23.3  -        -  

17  15.5  20.9  15.5  -       18.8  24.6  -        00.3

18  15.0  22.4  14.2  00.3    15.8  21.5  tr       tr  

19  09.8  19.6  07.8  -       19.1  23.3  -        -   

20  10.8  20.8  09.0  -       20.0  24.2  -        tr  

 

21  16.0  22.0  15.5  tr      19.9  23.1  tr       tr 

22  14.3  21.2  12.3  -       19.6  25.9  tr       tr  

23  13.7  23.3  11.8  -       20.2  25.7  -        -   

24  11.8  23.2  10.6  -       19.4  24.2  -        -   

25  12.2  20.1  11.6  -       17.1  22.9  tr       tr  

 

26  15.0  18.1  14.8  tr      16.7  21.8  tr       tr 

27  12.9  19.7  11.2  -       17.9  23.3  -        -   

28  12.3  22.3  09.0  -       20.8  26.8  -        -   

29  13.6  24.3  11.5  -       24.1  28.8  -        00.2     D

30  16.7  23.9  15.7  00.2    19.0  25.7  -        tr  

 

31  13.4  24.5  12.6  tr      20.6  28.2  -        -

 

Remarks:

A. night max. 2nd (16.6) occurred 02/09Z.

B. night max. 8th (16.4) occurred 08/09Z.

C. day min. 14th (14.7)[also 24hr min 15th] occurred 14/09Z

D. night max. 29th (24.3) occurred 29/09Z.

 

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

maximum temperature >= 21degC (70degF) = 47

minimum temperature >= 16degC (61degF) = 05