A great shelf and then a low topped supercell over Middelburg!

J.S.

Cumulus
Registo
26 Nov 2005
Mensagens
400
Local
Middelburg, Holanda
Hi,

Well whaty can I say...I wasn't very sharp and on thursday quite unlucky. I knew exactly what the radar looked like but watched the percipitation, whereas the shelf cloud was virtually on top of me....I did take pics of it over my city, rushed into the car as it was moving along side so I could possible get at a good distance to have a nice shot
1) 5 liters of gas in the car
2) Left my wallet in the rush at home

Result: couldn't take the risk of getting without gas, managed to get somewhere beyond it but a very slow driving person than prevented me to get at the right distance...

Here is a pic of someone else of this magnificent cloud. I think he overdid it in Photoshop but I have seen worse (stormchasers are to my mind excellent in compeletely destroying pics by overdoing it big time btw..).

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Shot by Dirk and this is over Werkendam.

Then friday promised to be a warm day. There was a lot of potential to my mind (Dp 22 C. Tx 27 C) so we had moist but heath was somewhat marginal. I just went to work but took my cam plus lenses with me. At 17 o'clock on my way home from Goes I noticed great looking storms over my hometown. It was explicitly said that cape was too low to produce any supercells. But I need to learn to go by my own knowledge.

Anyway, I saw cumuli sharply rising and thought that would at least make for a nice timelapse. I was 1 km south of my weatherstation at Middelburg North East....If I would have looked at the radar, I would have seen much more was going on or probably not because I was convinced nothing could happen...

But this was how it looked like

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What we have here and what I was unaware of is a low topped supercell. Funny: my weatherstation is where you see a few trees sticking over the cornfield...Now look at the righthand corner (bottom). This si where the cells updraft started and in fact a meso formed. A rotating supercell.

The quick development can be seen from these four radar images of the place and date..

17 o'clock..I was lookingh at the storm to the SW of me. I am at the black spot..

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Now lets see how the storm developped to the east of me which is the low topped SC.

At 17.30 we see a small white spot occuring on the radar. Red means > 10 mm/h precipitation btw

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17: 40, so ten minutes later: in ten minutes it has become a small, but very focussed storm

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Last pic of 17:50 h...It is getting a typical but also not very convincing Vshape...more elongated.
But it continued to devlop in the same spot spreading out north at the top after this for 15 minutes or so


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I made the pic B&W not to make it any nicer, but so we can see how it looked with much more contrast...

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And a second one just a bit later

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Again the main part to look at is the part to the right lower corner...Was it rotating? Yes..as you can see here:



The best part to my mind is at 50 to 52 seconds...look at the very large "foot" which is surround by some cumuli. It is rising up with a 30 degree angle because of the strong vertical shear...

When I saw the foot extending to the right, so against the flow I was alerted. I know this was no shelf at all. But I was also too late to get in closer.

It was not done after this. Sure the supercell went to sea and died quickly. But at 23.30 hour another one came in and this one was loaded with lightning. Like a strobscoop. The very heavy rains that accompanied it prevented me to shoot some nice lightning pics...

But before that I had a nice sundown anyways....

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Hoping for more to come...