Summary for March 2007

======================

HEADLINE: WET, WINDY START, THEN DRIER, QUIETER: SHARPLY COLDER 18TH-24TH

(last updated: 01/1200 April)

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):... 16.7(27)

Highest 24hr maximum (date):.. 16.7(27)

Lowest night minimum (date):... -00.8(22)

Lowest 24hr minimum (date):... -00.8(22)

Lowest overnight grass minimum (date):...-03.7(22)

[ number of days grass minimum < 0degC: ... 12 ]

[ Lowest day maximum (date):... 05.8(20)]

[ Highest night minimum (date):... 08.9(06)]

A. Mean Day (09-18Z) maximum: ... 11.4

A. Mean Night (18-09Z) minimum: ... 04.0

A. Mean of Day Max & Night min: ... 07.7

B. Mean 24hr maximum:... 11.4

B. Mean 24hr minimum:... 03.6

B. Mean of 24hr max & min:... 07.5 [+0.8 anomaly wrt eLTA of 6.7degC]

(data below relate to 24 hr day beginning 09Z on date given)

Nr of days minimum at 09UTC <0.0degC:02[dates: 21-22]

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:

This is the twelfth month in a row with a positive anomaly, though that for August last was only +0.3degC. With the markedly colder-than-average March 2006 dropping out of contention, the running 12 month anomaly is now a healthy +2.0degC.)

=================================

PRECIPITATION (PPN/mm)

Total rainfall/melted snow etc:... 049.0 [94% of eLTA of 52mm]

Highest 24hr total:............... 16.0(04)

No. days PPN total >= 0.2:14

No. days PPN total >= 1.0:10

No. days PPN total >=10.0:02

No. days PPN total >=25.0:00

(Notes relating to precipitation & allied observations:

28th Feb/1st Mar: r(slight)/r between ~23Z & 01Z (rainfall credited to February);

2nd: r(slight) began 1655Z, soon r, then periods of r(R) evening & overnight 2nd/3rd, ceased ~0430/0500Z;

3rd: ir(light/after persistent rain died away) between 0500Z & 0730Z; two pr(light) between 13 &14Z, one just sufficient to wet surfaces;

4th: r(slight) 0925, then r(slight)/r(R) to 1530Z, then ir(slight), bec. r(slight)/r continuous by 1740Z then r/R until 21Z; r(slight ocnl moderate) csd by midnight;

5th: pr(slight) 1330-1340Z, r(slight), isol moderate, between 1540 & 1630Z.

5th/6th: r/R evening & night (continuous, with strong wind to ~05Z), ceased by 06/0630Z;

7th: r(slight), ocnl r, between 03 & 05Z; pr(very light/few drops)~16Z;

8th/9th: r(slight)/r between 08/22Z & just after midnight, then ir/d(slight) until 09/04Z;

18th: sporadic rain (mainly light) from early hours, with persistent (ocnl r) rain ~0330/0400Z; showery from ~0530Z to 0730Z; phr(mix small hail / moderate rain) 1125-1135Z, ph(slight/snow pellets)~1240Z, otherwise, a few passing light showers of rain. prh(dia.>5mm, max~7mm) 1923-1935Z;

19th: r/rs, tempo s(slight) between 0230 & 0330Z, otherwise pr(very light) until ~08Z: through afternoon, several prs/s(mainly slight), but short-lived moderate snow pellets/rain shower ~15Z, with thunder ~1510Z; further showers rain/small hail until ~19Z;

20th: sporadic rain/rs(all slight) early hours onwards, ceased by 0730Z. mixture prs(slight, isol moderate), ps(slight), prh(slight, small hail) between 1330 & 1630Z; prh(slight/<5mm) ~1840Z;

22nd: s(slight), short-lived s, between 0630 & 0815Z, then rs(slight) until~10Z, ceased by 11Z. Further ir(slight) 1445-16Z; r(slight)/r between 1815 & 20Z;

22nd/23rd: periods rain, light, ocnl moderate/dr overnight until ~0820Z;

23rd: sporadic r(slight) through day, mainly PM;

24th: id(very light) PM, becoming persistent by 18Z: ir(slight) evening;

25th: ir(slight)~08Z

29th: ir(slight) from ~0645Z, becoming r(slight)/r between ~11Z & 1130Z, then ceased. pr(slight) until mid-afternoon;

30th: sporadic rain (light, isol moderate) early-hours onward. Slight, ocnl moderate r from 11Z until well into the evening;

31st: pr(slight) 13/1330Z;)

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OTHER TOTALS

Number of days thunder heard: (dates).. 01 (19)

Number of days hail < 0.5cm diameter:.. 02

Number of days hail >=0.5cm diameter:.. 01

Number of days snow/rain & snow:....... 04

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 March, 2006

3rd/4th: (night) combination of heavy dew & thick/wet fog (latter between 02 & 05Z) gave rise to 0.1mm in gauge at 04/09Z

18th: phr(mix small hail / moderate rain) 1125-1135Z; prh(dia.>5mm, max~7mm) 1923-1935Z

19th: phr(mix small hail / moderate rain) 1850-1900Z

20th: prh(slight, small hail, insignificant amounts) between 1330 & 1630Z, together with other 'wintry' showers (q.v.); prh(slight/<5mm) ~1840Z

31st: markedly gusty wind PM, ocnl F6(F7)

[thunder]

19th: a 'sharp' CG discharge ~1508Z, followed by a distant CC, as previous rain/snow or snow pellet shower moved away

[snow]

18th: light shower snow pellets (diameters up to 6mm), but soon melting.

19th: r/rs, tempo s(slight) between 0230 & 0330Z. Through afternoon, several prs/s(mainly slight), but short-lived moderate snow pellets/rain shower ~15Z.

20th: rs(slight/few melting flakes) ~07Z. Mixture prs(slight, isol moderate), ps(slight)between 1330 & 1630Z.

22nd: s(slight), short-lived s, between 0630Z & 0815Z, then rs(slight), only temporary (~0.5cm) covering grass etc., none on roads. Sleet to ~10Z.

... 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 04.6 09.6 02.0 01.8 06.0 10.0 - - -

02 01.2 08.3 -01.5 - 03.7 10.3 01.4 07.0 A

03 04.4 07.9 03.6 05.6 07.0 12.0 tr 00.1

04 04.1 09.6 00.7 00.1wf 07.9 11.1 08.3 16.0 wf=dew+fog

05 05.2 11.2 03.0 07.7 06.2 11.1 00.7 11.5 BC

06 08.9 10.3 07.2 10.8 10.0 12.8 - 00.6

07 05.4 10.5 02.3 00.6 06.3 11.6 tr tr

08 02.0 09.6 -00.5 tr w 05.0 12.5 - 01.9 w=dew

09 07.6 10.6 05.2 01.9 07.9 11.4 - tr

10 04.1 09.8 01.1 tr w 06.6 12.5 - tr w=dew

11 05.4 11.0 01.7 tr w 08.5 15.5 - -

12 06.0 11.4 00.6 - 09.8 15.5 - -

13 04.4 13.0 01.6 - 07.3 12.8 - -

14 01.3 10.4 -00.8 - 05.5 12.5 - -

15 02.5 11.2 -00.9 - 06.5 11.2 - -

16 06.0 10.5 02.3 - 07.4 12.5 - - D

17 07.8 11.4 05.7 - 10.9 14.5 - 00.5

18 06.9 10.9 05.3 00.5 04.6 09.1 tr 01.0

19 01.2 04.6 -00.4 01.0 03.0 07.4 00.9 01.7 E

20 01.6 04.4 -00.1 00.8 03.2 05.8 00.2 00.2

21 -00.6 03.5 -02.6 tr 01.9 07.5 - 01.0

22 -00.8 06.0 -03.7 01.0 01.2 06.4 00.4 01.3 F

23 05.3 06.1 03.8 00.9 06.0 07.1 00.2 00.2

24 02.8 06.9 -00.5 - 05.8 07.6 tr 00.1

25 05.8 07.4 05.7 00.1 07.4 12.3 - -

26 01.8 10.5 -00.5 - 06.7 15.0 - -

27 01.4 12.3 -01.4 - 06.0 16.7 - -

28 01.6 14.0 -01.6 - 05.1 15.7 - tr eve.ob 2030Z G

29 06.7 (09.7) 02.9 tr 05.7 09.4 00.8 01.5 H

30 03.4 07.0 01.1 00.7 06.9 08.4 03.3 04.4

31 06.8 08.8 05.8 01.1 08.8 14.8 tr tr I

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.(3.7), also 24hr min 3rd, occurred 02/09Z

B. night max.(11.2), also 24hr max 4th, occurred early evening 4th

C. day min.(6.2), also 24hr min 6th, occurred 05/09Z

D. day min.(7.4), also 24hr min 17th, occurred 16/09Z

E. day min.(3.0) occurred in association with early afternoon sleet, snow and/or snow pellet shower

F. day min.(1.2), also 24hr min. 23rd, occurred 22/09Z

G. day min.(5.1), also 24hr min. 29th, occurred 28/09Z

H. night max.(9.7) covers period 28/2030 to 20/0900Z

I. night max.(8.8), also 24hr max. 30th occurred 31/09Z

Number of occasions (24hr periods) THIS YEAR (2007)

maximum temperature >= 21degC (70degF) = 00

minimum temperature >= 16degC (61degF) = 00

Rolling 12 month temperature anomaly: +2.0 (was +1.8 end last month)

[PRECIPITATION]

The precipitation %age for the month was 94%, effectively 'average' rainfall. However, a large proportion of the 49mm fell within the two 'rain-days' of the 4th & 5th: 27.5mm (over half of the month's total), and taking the month as a whole, there were lengthy periods with small or nil amounts of rainfall.