Wednesday, August 10, 2005

Nights of 8/9 and 9/10 August

There was some moderate lightning activity present during both nights within the reach of our cameras, but unfortunatelly we didn't capture any sprites.


Blogger Jan Hemmer said...

Hello Matt,

I have just returned from a holiday in France where I stayed with my wife (and a lot of visiting relatives and friends) in our french farmhouse that we bought 3 and a half years ago.
One of the nicest things about that place (in the department of the Creuse, so right in the centre of France) are the pitch-black nightskies.
Sitting at night in the garden with a clear view to the south, there are absolutely no artificial lightsources to be seen.
So last week on the 10th of august, I was sitting there with my brother (and other relatives in the background) waiting for some early perseid meteors. The new moon had just sunken below the horizon and all lights were out. We saw one bright falling star but most prominent were the flashes of lightning from a violent thunderstorm a few hundred kilometers away to the south in the Pyrenees, visible as white brightenings close to the horizon, without sound of course.
We were looking keenly at the lightnings to see if the storm was moving and our eyes were probably very much adapted to the dark, when suddenly we saw above the storm a very brief moment a rectangular patch of light, the size of roughly two full moons. It was so peculiar that my brother and I discussed it at once and I voiced my opinion that maybe it might have been a sprite, which he only had heard distant mention of. No colour could be distinguised, which is logical in my opinion because the dark adapted human eye is unable to do just that.
After about five minutes the same thing happened again, the same brief patch of light which could not be a reflection because there were no clouds to be seen in that part of the sky, only stars were visible. In fact the whole sky above us was quite clear. After that it happened three times more and the last was even with three patches of light at once. All without visible connection or tendrills reaching into the cloudtop.
The phenomenon seemed to be moving to the east. The clouds of the storm were not visible or very close to the horizon and the elevation of the sprites from our viewpoint was an estimated 10 degrees.
After an hour we went inside the house because nothing much happened anymore, although at certain times the cows and the dogs in the neighbourhood were quite exited. "By what?" I cannot keep myself from wondering.
People should stay outside in nights like this, but the bed is so warm and tempting and the flesh is weak.
I am going to try and get a low level light-camera from somewhere.

Jan Hemmer
St. Maarten

August 19, 2005 7:38 pm  
Blogger Oscar van der Velde said...

Hello Jan!

thank you very much for sharing your interesting story with us! You have unmistakably seen sprites, and call yourself very lucky because there are almost no people who have seen them and know it, especially in Europe.

Do you know an approximate time period when they happened? I believe it could indeed be the night of 9/10 August or also 10/11, but the latter storm system had a more expansive cirrus cloud shield sometimes reaching over the Creuse department.

I am currently looking into the raw event images, the live uploads that day did not work, just like many raw event image uploads the next day (size 0k) and it could be there may be some sprites hidden in it, it would be a pleasant surprise... not sure the camera saw a clear sky though.

Keep us updated if you catch any sprites if you managed to catch them on video - good observing days are rare!

Oscar van der Velde

August 20, 2005 3:45 pm  
Anonymous Anonymous said...

Hello Oscar,

Sorry about the cryptic "Hello Matt" - part, this is a copy-paste mistake because I also posted the story to Matt Heavner in Alaska.

The exact date I do know because it was my brothers birthday at the 10th of August so it was the night of 10 - 11 august.
The exact time however I must reconstruct. I know the first lightning strikes at the horizon happened after 10, estimated 10.15 because I remember discussing if it might also have been fireworks, but I also know that in France those usually start at 11 o'clock in the evening and so for fireworks it was too early. The first sprite was at a time about half an hour later, in any case after the moon had set, so at 22.45h local time.
The interval between the subsequent sprites was 10 to 15 minutes and I remember going to bed around midnight.
Since the last (threefold) sprite I waited for about half an hour in which nothing special happened anymore.
So this is the best I can do exept one thing I did not specify in the report i.e. that there was no distinguishable structure or striation to be seen in the patches of light.
Not that there was none but it was to faint for at least my eyes to see.
Question: Do you know a way to get a cheap low level light-camera?

August 21, 2005 11:59 am  
Anonymous Anonymous said...

Hi Oscar,

As a regular on UKww I have found the data on your site essential :)

Back on topic, My wife and I were on our honeymoon on the 10th August in Capestang, SW France and we had the storm right over us! I think it would of been quite possible for this storm to develop sprites as there was a very high lightning rate between 50 and 200 strikes per minute with 75% being of the IC type. We saw this storm approaching from our south at approx 10pm, and at around 10.30 we got the first strong convective outflow gust, which was approx 70kph in strength, then we got approx 30min of very heavy rain from around 11.15pm. The storm finally departed to our North at around 1am, so it must of been very slow moving? We are currently converting some analogue video of this storm to mpg format if your interested?

August 21, 2005 4:20 pm  

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