Emily's Weather Blog

Sensors offline : 18-10-2011 08:00 – 15:00 BST

em — Tue, 18 Oct 2011 15:14:06 +0000

The automated sensor array has been offline between approximately 08:00 and 15:00 BST today (18/10/2011).

This was to allow re-cabling in the server room and to swap over PSUs on the POE connection to the sensor array.

Data will be modified to reflect this gap shortly.

The last of the summer sun

em — Mon, 03 Oct 2011 16:15:24 +0000

Well it seems that last weekend was probably the last of the summer sun that we are going to see this year, my new sensors record a temperature of 31 degrees averaging 28-29 over the last few day. However as you will be able to see from the latest satellite image, a large bank of cloud has moved in from over the Atlantic and is now rapidly moving across the country, as I am writing the sky is clouding over to almost 8ths of cloud cover and the wind has picked up dramatically. Autumn is defiantly here.

Snow??

em — Fri, 30 Sep 2011 16:47:29 +0000

Well, sadly no. This is early morning fog forming over the local hills. This specific photo was taken on Tuesday however this fog has occurred most mornings this week, there has been no fog at ground level, just the usual autumnal dew.

Having done some research i think it only occurred on the hills, because the air temperature in the hills is slightly cooler, colder air can hold less water so it condensed forming the fog, if it had been cooler on ground level we would also of had the fog.

NEW!! sensor array

em — Thu, 22 Sep 2011 16:18:29 +0000

The remote sensor system is up running, the data is now displayed on the live data page for the current data and a multitude of other graphs.

Keep checking the live data page as I am still thinking of new ways to display the data I have collected.

Go over to the equipment page to see how the system works.

Preliminary livedata tests

g7nbp — Tue, 06 Sep 2011 09:52:03 +0000

Well, its been a busy summer!

Initial tests from my remote sensors project are now running from the livedata page – be sure to check back frequently as I bring more features online.

Sensor test results table

g7nbp — Mon, 11 Jul 2011 05:30:21 +0000

As promised at the end of last month, an evaluation of the sensor values under differing light conditions.

	Time	0hms	Cloud cover (8ths)	Description	Observer
12/06/11	04:45AM	3300	1	pre sunrise Clouds on eastern horizon, lit by sunlight – sun behind hills	chrisw
	05:00AM	2000	1	Sunrise – sun just behind trees	chrisw
	05:07AM	1750	1	Sunrise – cirrus band and blue sky overhead	chrisw
	05:10AM	2000	1	Same conditions but in shadow area to get down scatter reading	chrisw
	05:15AM	1050	1	blue sky cirrus clouds overhead sun about 3 degrees above horizon	emily
	05:30AM	800	1	same conditions but sun about 1-2 degrees higher	emily
	05:45AM	700	2	cirrus clouds and blue sky sun at 5 degrees bank of cloud coming in from south not yet affecting readings	emily
	06:00AM	450	3	cirrus cloud still above sun at about 7 degrees bank of cloud from south moving further north	emily
	06:15AM	375	5	cirrus cloud and blue sky still above sun at about 10 degrees bank of cloud from south almost over head though	emily
	06:25AM	435	7	sun slightly covered by thin bank of cirrus cloud and cloud from south over head now beginning to affect readings	emily
	06:40AM	700	8	only last snipits of blue sky sun covered by clouds from south (now covering most of the sky), sun at 13 degrees	emily
	06:55AM	635	8	sun covered by thick cloud at about 17 degrees	emily
	07:15AM	800	8	sun now not visible behind cloud	emily
	07:50AM	700	8	sun now not visible behind cloud raining at the moment (light to medium rain)	emily
	08:30AM	700	8	still raining and still no visible sun	emily
	09:00AM	650	8	clouds slightly lighter white still raining and wind picking up	emily
	09:30AM	700	8	full sky of thick cloud no visible sun, medium rain and wind picking up	emily
	10:00AM	550	8	full sky of thick cloud still no visible sun wind dying down rain picking up	emily
	10:30AM	430	8	cloud directly above head whitening slightly, rain still getting heavier.	emily
	11:00AM	500	8	cloud not any whiter, rain dying down	emily
	11:30AM	480	8	cloud not any whiter, rain the same	emily
	12:00PM	550	8	Same conditions as before	emily
	12:30PM	530	8	Same cloud yet raining heavily	emily
	01:45PM	545	8	clouds slightly lighter white still raining	emily
	02:30PM	590	8	Same cloud yet raining getting lighter	emily
	03:00PM	530	8	raining heavily clouds still full covering sky	emily
	04:00PM	680	8	Overcast	chrisw
	06:00PM	650	8	still overcast	emily
	07:00PM	750	8	still overcast	emily
	07:30PM	670	8	still overcast but clouds lightening in colour	emily
	08:00PM	900	8	odd snipits of blue sky overhead but low cloud/ fog coming in from south	emily
	08:40PM	1600	8	blue sky gone low cloud from south still moving in	emily
	08:55PM	3330	8	dark low lying clouds, drizzle	emily
	09:05PM	3700	8	Still dark low lying clouds, drizzle	emily
	09:15PM	3800	8	same as above	emily
	09:20PM	6500	8	same as above	emily
	09:29PM	7400	8	Supposed sun set however unknown because sun covered by thick cloud, still drizzle	emily
	09:35PM	10000	8	beginning to darken slightly.	emily
	09:50PM	25500	8	slightly darker but still drizzling	emily
	10:00PM	72000	8	getting darker almost black sky yet still able to see drizzle stopped	emily
	10:08PM	160000	8	dusk	chrisw
	10:20PM	600000	8	dusk	chrisw
	10:35PM	2350000	8	dark	emily
13/06/11	10:20AM	240	5	broken cloud – in sunshine	chrisw
	11:00AM	290	6	sun behind thin white cloud	chrisw
	12:40PM	250	4	broken white cloud – sun unobstructed	chrisw
	07:05PM	298	3	cirrus partially obscuring sun	chrisw
	09:55PM	12400	2	10 mins after sunset	chrisw
14/06/11	01:00AM	24000000	2	moonlight ¾ moon	chrisw

So, in conclusion the simple photo-resistor (LDR) sensors chosen give a range of values ranging from a few hundred Ohms in bright sunlight, to over 20M Ohms under moonlight.

This is obviously too wide a range of values to cover with a single scale (there are only 1023 steps on the ADC input on the micro-controller board I will be using) – so tests and some graphing will follow to chose what ranges to cover

I have located a conversion table for EV (exposure value) to Lux for our photographic light meter, so will retest some of the above typical values in conjunction with the Lux reading to give some more measurable values to the table

Composite pasess 05:03 and 06:44 UTC today

em — Tue, 28 Jun 2011 09:50:30 +0000

This mornings passes of NOAA15 as a composite

Proc: MCIR

Composite pasess 15:14 and 16:55 UTC today

em — Mon, 27 Jun 2011 19:17:20 +0000

A quick composite of sequential NOAA15 passes today at 15:14 (right) and 16:55 (left) UTC – showing north Atlantic and northern Europe, centred on home.

processing is Multi-Channel IR (MCIR)

Compositing editor: Daddy

Sensor tests – update

g7nbp — Sun, 12 Jun 2011 18:42:44 +0000

As Emily has commented, tests have been running throughout the day. The morning started bright with blue skies and some thin cirrus cloud, but as the morning progressed a weather front moved in from the south bringing in rain and total cloud cover.

04:08UTC – the front clearly visible just south of home

06:2UTC – Thick cloud now fully obscuring the sky

16:15UTC – The cloud cover now thinner but still 8/8ths coverage here.

The results so far have however been useful. We have a good range of data from the sensor tests under overcast conditions. (results will follow). The forecast for tomorrow is brighter, so I hope to run a few additional tests under clear sky conditions at 12:00UTC to get a maximum brightness reading, and if conditions permit Emily will take some further clear sky sunset and dusk readings to add to the data.

light sensor testing

em — Sun, 12 Jun 2011 07:27:03 +0000

Today I am testing my light sensor in different light levels at regular intervals in the day (every 15 minuets), I started just before sunrise 4:42 and am going to carry on recording data until after sun set 9:29 to give me maximum range of light levels.