Summary for January 2006

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

HEADLINE: DRY. MILD/DULL 'TIL WELL AFTER MID-MONTH; COLD/SUNNY FROM 20TH

(last updated: 01/1200 FEBRUARY)

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):... 12.2(18)

Highest 24hr maximum (date):.. 12.2(18)

Lowest night minimum (date):...-03.4(24)

Lowest 24hr minimum (date):...-03.4(24)

Lowest overnight grass minimum (date):...-05.5(25)

[ number of days grass minimum < 0degC: ... 11 ]

[ Lowest day maximum (date):... 02.5(07)]

[ Highest night minimum (date):... 08.0(19)]

A. Mean Day (09-18Z) maximum: ... 06.6

A. Mean Night (18-09Z) minimum: ... 02.9

A. Mean of Day Max & Night min: ... 04.7

B. Mean 24hr maximum:... 06.7

B. Mean 24hr minimum:... 02.5

B. Mean of 24hr max & min:... 04.6 [+0.4 anomaly on eLTA of 4.2degC]

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

Nr of days minimum at 09UTC <0.0degC:08[dates: 12,22-26,28-29]

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:

Coldest January this site since 2003.)

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PRECIPITATION (PPN/mm)

Total rainfall/melted snow etc:... 024.4 [37% of eLTA of 66 mm]

Highest 24hr total:............... 10.7(08)

No. days PPN total >= 0.2:12

No. days PPN total >= 1.0:07

No. days PPN total >=10.0:01

No. days PPN total >=25.0:00

(Notes relating to precipitation & allied observations:

1st: pr (slight/moderate) in overnight period 31st Dec/1st, credited to December's total; further light showers (rain) until ~ midday;

2nd/3rd: ir(very light) evening, overnight & early morning;

3rd: idr(slight) through afternoon / evening, with period r mid-afternoon;

4th: ocnl r(mainly slight) through day;

5th: r(mainly slight) from early hours, dying out late morning;

5th/6th: very light rain/drizzle overnight & at 09Z ob, dying out soon thereafter;

7th: r(slight) 0800Z ->rs(slight) 0825Z -> s(slight) 0830Z -> rs/d(slight) 0930Z; csd (as slight rain) by 1103Z;

8th: r(slight) began ~1145Z, soon r(R), continuing at 18Z: through evening becoming lighter (though with moderate bursts before 21Z), with rain / drizzle mostly dying out by midnight;

9th: id(slight) 10-11Z;

10th: ir(slight) from 16Z, bec. continuous by 18Z;

10th/11th: r(slight), ocnl moderate through night, accompanied by strong winds: period r/R ~0815Z (ana-frontal passage), then light by 09Z, dying out completely by 0930Z;

14th: ir(light) 05-08Z; r(slight),ocnl r 0930Z-1645Z, with period r/R (frontal passage) 1600-1630Z; further ir(light/moderate) evening;

15th/16th: ir(slight/moderate) overnight;

16th: periods r(slight)/r, short period R, through day; further r(slight)/r during evening;

18th: ir(slight/moderate) early hours; pr(slight)~0845Z; further light dr remaining part of morning;

19th: light d from early hours, dying out mid-morning;

20th: r(slight)/r/strong winds ~06Z to 0805Z, with R/q on ana-cold frontal passage 0750-0805Z; pr ~ 0825-0840Z;

25th: ir(very light) ~1040Z; pr(slight) 1630-1640Z;

27th: rs(slight),[with short spell~1940-1950Z s(also very slight)] between 1845-2045Z;

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OTHER TOTALS

Number of days thunder heard: (dates).. 00

Number of days hail < 0.5cm diameter:.. 00

Number of days hail >=0.5cm diameter:.. 00

Number of days snow/rain & snow:....... 02

Number of days snow lying at 09UTC:.... 00

Deepest snow cover (date,s):........... -

Number of days fog (visibility < 1km @ 09UTC).. 01

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Additional comments on the weather in January, 2006

8th/9th: a misty night, with visibility occasionally <1km (fog), but not at 09/09Z;

22nd: i/jf overnight, had cleared by 06Z, but reformed ~0830Z;

24th/25th: periods of f overnight (<500m at times), but lifted above 1km by 25/06Z;

[rainfall]

This has been the driest January in a composite Easthampstead Park / Tawfield record (starts 1971) since 2000.

Last January (2005) was also dry, with 26.6mm, & was part of a dry winter.

In the composite record, there have been 6 drier Januarys, 4 of them (1973, 1976, 1987 & 1992) were followed by notably dry Februarys – indicating some tendency to persistence of type?

[thunder]

none

[snow]

7th: light rain/snow or snow 0825-1030Z;

27th: rs(slight),[with short spell~1940Z s(also very slight)] between 1845-2045Z. No impact on surface (other than to make it wet);

... 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 03.8 06.4 02.4 01.0 05.9 07.3 00.1 00.1 -

02 03.9 06.8 01.1 - 04.4 06.9 - tr A

03 05.2 06.6 03.2 tr 06.6 09.5 01.1 01.1

04 05.5 09.2 04.0 tr 03.3 06.5 00.4 00.6

05 01.1 03.3 -01.0 00.2 01.9 03.4 tr tr

06 01.6 01.9 01.2 tr 01.9 03.6 tr 00.3

07 00.8 03.4 -00.3 00.3 00.8 02.5 01.0 01.0 B

08 01.6 03.4 01.0 - 03.4 04.3 06.5 10.7 CD

09 03.7 04.2 03.4 04.2 04.2 06.0 tr tr

10 03.9 06.5 02.7 - 06.5 07.7 tr 02.1 EF

11 07.4 09.0 07.1 02.1 05.0 09.1 tr tr G

12 -00.1 05.0 -02.5 tr(x) 02.5 05.8 - - H (x=hoar)

13 05.5 06.2 04.6 - 06.1 07.5 - tr IJ

14 07.2 07.7 06.0 tr 07.0 08.6 02.2 02.4 K

15 06.5 07.0 05.6 00.2 06.7 08.1 - 00.3

16 06.1 07.2 04.9 00.3 05.7 09.0 01.9 03.2

17 05.0 07.6 03.3 01.3 06.9 09.5 - 00.9

18 05.6 09.2 03.6 00.9 09.2 12.2 00.2 00.2 L

19 08.0 10.8 05.5 tr 09.4 10.6 tr 01.4

20 07.4 10.2 06.3 01.4 06.1 08.9 - -

21 02.9 06.1 00.2 - 04.6 09.0 - -

22 -01.6 04.6 -04.0 - -01.4 04.8 - - M

23 00.0 02.2 -02.8 - 01.6 03.2 - -

24 -03.4 01.6 -05.4 - -03.2 02.9 - -

25 -03.3 01.1 -05.5 - -01.3 05.5 tr tr N

26 00.3 04.2 -02.2 - 01.4 05.0 - -

27 00.1 04.0 -01.5 - 00.2 04.1 - 00.1

28 -00.9 02.9 -02.2 00.1 -00.4 05.1 - -

29 -00.8 03.6 -02.8 - 00.2 05.9 - - O

30 03.0 04.7 01.5 - 04.7 06.0 - -

31 03.3 04.9 03.0 - 02.7 05.5 - -

Remarks:

A. day min.(4.4), also 24hr min. 3rd, occurred 02/09Z

B. day min.(0.8), also 24hr min. 8th, occurred 07/09Z

C. night max.(3.4), also 24hr max. 7th, occurred 08/09Z

D. day min.(3.4), also 24hr min. 9th, occurred 08/09Z

E. night max.(6.5), also 24hr max. 9th, occurred 10/09Z

F. day min.(6.5), also 24hr min. 11th, occurred 10/09Z

G. night max.(9.0), also 24hr max. 10th, occurred 11/09Z

H. day min.(2.5), also 24hr min. 13th, occurred 12/09Z

I. night max.(6.2), also 24hr max. 12th, occurred late in night

J. day min.(6.1), also 24hr min 14th, occurred 13/09Z

K. night max.(7.7), also 24hr max 13th, occurred 14/09Z

L. night max.(9.2) occurred 09Z (air mass change overnight)

M. day min.(-1.4), also 24hr min 23rd, occurred 22/09Z

N. day min.(-1.3), also 24hr min 26th, occurred 25/09Z

O. day min.(0.2), also 24hr min 30th, occurred 29/09Z

Heathrow sunshine: 51.4hr ( 99% of 61-90 average of 52hr)

Number of occasions (24hr periods) THIS YEAR (2006)

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

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

[Summary]

Winter so far (December & January)

Based on the time we have been here (winter 1999/2000 onwards)

Currently (end Jan), in terms of mean (24hr) temperature, it is the coldest winter since 2001/02;

In terms of air frost days, 2001/02 had more (26) than this winter (21) at the same point;

In terms of snow falling, we've had 6 so far, the same as in 1999/2000 & 2000/01.

In terms of snow lying at 09Z, we've had 0 (zero) so far: as recently as 2003/04 we experienced 2 days with snow lying and in 2002/03, by this time, there had been 5 days with snow lying at 09Z.

Overall, this winter so far (in terms of snow, frost, temperature) for us has been unremarkable, with a 2-month anomaly on 24hr temperature of

–0.3degC on the 1971-2000 eLTA. Given that the 71-00 base-set was warmer than the 61-90 used by the Met Office, it may in fact be regarded as "around average".

Martin.