September 2010

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Paul C
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September 2010

Post by Paul C » Fri Oct 01, 2010 7:13 pm

For Brampton

Mean 13.2c
Mean Max 16.9c
Mean Min 9.5c

High Max 21.9c 3rd
Low Max 11.1c 24th
Low Min 1.3c 25th
High Min 14.7c 6th
Low Grass Min -4.0c 25th

Rainfall 85.3mm (105%)
Wettest Day 16.6mm 13th

Sunshine 115.1hrs
Grass Frost 3
Air Frost Nil
Gales - 2
Strongest Gust 42.6knots 14th
Hail/Fog - zero

Overall an Average month rainfall wise and Mean temperatures just about bang on average. Some cool nights with several grass frosts.

RumZ
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Re: September 2010

Post by RumZ » Sat Oct 02, 2010 4:36 pm

For Shap Village

Mean 12.3c

High Max 21.4c 3rd
Low Max 10.9c 24th
Low Min 2.7c 25th
High Min 12.6c 20th

Rainfall 107.4mm
Wettest Day 19.8mm 23rd
Rain days: 18

Nothing eventful really,
The 14th recorded my fastest rainfall rate of 2010 peaking at 105.4mm/hr
and I suspect the 8th will have been the last 20C+ temp I see until next May.
Still waiting for that first air frost, 143 days without a sub 0C temperature.

Anne
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Re: September 2010

Post by Anne » Sat Oct 02, 2010 6:10 pm

Here's my report for Scotby. Pretty wet and one of the coldest September nights (I've only had 3 air frosts in 23 years and the lowest was -0.5C)
Anne

After a warm dry start September's weather became increasingly unsettled and autumnal. During the first 10 days the temperatures were above 20C every day, with plenty of sunshine and a maximum temperature of 23.8C on both the 2nd and 3rd. This warm spell made this September warmer on average than the last four years. However, from the 11th it became gradually cooler, with strong, blustery winds in the second week. Several nights at the end of the month were very cold, with a minimum of 0.2C, almost a frost and one of the coldest September nights I have recorded in Scotby.

The total rainfall for September was 103.2mm. September is usually a relatively dry month; this was only the third time I have recorded over 100mm for the month. The average for September is about 73mm. There were 18 days with rain recorded, the only dry spell was at the start of the month. The wettest day was the 29th with 15.2mm.

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darrog
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Re: September 2010

Post by darrog » Sat Oct 02, 2010 8:40 pm

SEPTEMBER IN MM

TEMP

Mean = 12.5c
Mean Min' = 8.4c
Mean Max' = 16.8c

I only have 4yrs data for Sept' but 12.55c is now the months means, but that Mean max' is by far the highest in those 4yrs and the Mean Min' is also the lowest in that time!

High Max' 22.7c (2nd)
Low Max' 11.1c (24th)

Low Min' 2.2c (17th)
High Min' 12.8c (6th)

Grass +0.2 (17th)

x6 days attained 20c and the first 5 days all got there - the summer months could only produce a run of 3 successive days at 20.0c

RAIN

SNOWDON GAUGE = 87.9 mm --17 rain days and 15 wet days -- Wettest day (23rd) 16.4mm

VPro 2 = 83.0 mm -- 20 rain days of which 13 wet days -- wettest day 23rd 21.8 mm
VPro 2 0900x0900 hrs = 83.2 mm -- 20 rain days and 15 wet days.

WIND

Average of 5.9 mph
Max' gust of 40 mph on 13/14/15th
predominant sw'ly

PRESSURE

mean at 0900 hrs -- 1012.6 hpa
High = 1023.3 hpa
Low = 996.3 hpa

CLOUD

Mean at 0900 hrs = 75.33%
Darren Rogers - he who submits the most interesting posts, AKA Mr Data
Maulds Meaburn

Anne
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Re: September 2010

Post by Anne » Sat Oct 02, 2010 10:15 pm

So how do you think the strange differences in the Snowdon gauge to the others happened? It seems really very odd that it recorded fewer rain days but more rain; although less rain on the wettest day???? :?


And talking of errors ..... I have found that my maths has let me down in the last two months - both times I got a different rainfall total in my book record (that I fill in each day with a running total) to the rain total that my weather station listed.
Of course it was human error (dim wit!) and now I am left wondering how many other months' totals over 23 years are incorrect :( :( :( . I'm not going back over them all though!

Anne

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darrog
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Re: September 2010

Post by darrog » Sat Oct 02, 2010 10:42 pm

I read the manual (snowdon) gauge at 0900 hrs so whilst the Vpro2 has a higher midnight - midnight reading, the snowdon did actual record the most out of the two over the period of rainfall (22nd/23rd).
snowdon = 29.2 mm
Vpro2 = 27.4 mm

When I checked the Vpro2 readings for 0900x0900 hrs they did tend to be quite similar (usually within 0.2mm) to that of the snowdon, the greater differences tended to be when there was a high amount of rainfall and the Snowdon always reads more.

the other point would be that on the 4 days the snowdon is recorded as 'Trace' the Vpro2 had 0.2mm on 3 of them and 0.0mm on the other.

the difference in 'rain days' is mainly down to that erroneous 0.2mm tip on days of little rain.
the Vpro2, as with any tipping bucket is always going to be prone to that 0.2mm tip on little rainfall due to it having some rain in the bucket from past rainfall (but not enough to tip).
From winter I also recall the 0.2mm tip due to melting frost (had 7 such days in Feb') and only this week the heavy dew as caused x2 0.2mm tips (one today, but it is now raining and hence won't effect the No. of rain days).

When I got the Snowdon i did expect to get a higher reading with it than with the VPro2, but after two months now that difference is not as marked as i expected - and many would say well within any margin of error.
The chap who kindly gave me the Snowdon also expected a greater difference, 5 - 30%.

In just two months the Snowdon has a total of 146.9 mm to the Vpr02 0900x0900 hrs of 140.6mm.
But far more interesting is the difference in rain days:
Snowdon = 32 rain days and 24 wet days
Vpro2 = 41 rain days and 24 wet days

still early days yet though.
Darren Rogers - he who submits the most interesting posts, AKA Mr Data
Maulds Meaburn

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Carl M
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Re: September 2010

Post by Carl M » Sun Oct 03, 2010 12:03 pm

Drumburgh figures

M.MAX: 18.0c +0.8
M.MIN: 9.4c +0.4
MEAN: 13.7c +0.6

H.MAX: 21.7c 4th
L.MAX: 12.5c 24th
L.MIN: 0.7c 26th
H.MIN: 14.7c 11th

G.MIN: -4.1c 25th

Rainfall

TOTAL 96.4mm 128%

Most: 15.6mm 6th
0.2 15
1.0 15

Thunder 1
AF 0
GF 4
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Drumburgh 7m AMSL (Solway Estuary)
http://www.coggabata.co.uk/weather.html

Anne
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Re: September 2010

Post by Anne » Sun Oct 03, 2010 10:07 pm

Thanks for that Darren. Interesting! Statistics, damned statistics!.

Quote "the greater differences tended to be when there was a high amount of rainfall and the Snowdon always reads more."
Why do you think that is? Is it possible its experiencing 'splash back'? Do you think the height of the lip of the gauge makes any difference? Not criticising here - just interested at the differences :)


My maths isn't up to working out statistical significance, but it would be interesting to know what the significance will be over a full year.

Anne

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darrog
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Re: September 2010

Post by darrog » Tue Oct 05, 2010 12:13 am

Ann, it shouldn't be splash back - set at 12" (30cms0 above the ground) - memory tells me that decades ago the standard height was 6" and for that reason (splashback) it was changed to 12".

You need to read the analysis/comparison that Stephen Burt did on the VPro2 v standard equipment, you can read it on the PRODATA website - the section on the raingauge is interesting.
If gives the account of the VPro2 guage been set at the default height of 5ft above the ground, due to setting the main body at 4ft to get the proper air temp.
And that because the standard gauge is set at 12" it is less prone to the effects of the wind blowing rain away and hence should read higher.
however, in his year of comparisons whilst the final yearly totals of standard v VPro2 were remarkably similar, daily and even monthly totals varied quite a bit.
The surprising outcome was in the years comparison the VPro2 recorded more rain than the standard!
I got my rain gauge from Philp Eden and he quotes a 5-30% under recording by the VPro2 - i think that the main reason is due to its default height, when strong winds will be a significant factor, but again still a little early to say for myself.
Darren Rogers - he who submits the most interesting posts, AKA Mr Data
Maulds Meaburn

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