Hello, I'm Robert van de Velde from the Netherlands. I am 15 years old and I live in Sint Philipsland, a village with a little more than 2000 inhabitants in the province (a province is like a county in the US) Zeeland (Zealand). I got interested in the weather a year ago when it was very muggy (the CAPE was 4000+ and that's very high in the Netherlands) and serious thunderstorms were expected but eventually I hadn't seen any thunderstorms except some ominous skies.
In the Netherlands we have a few tens of supercells every year so they are quite rare. Since I'm not yet allowed to drive a car I can't go to the storms so the storms have to come to me. I had always wanted to see a supercell above my home village. Last Sunday I got lucky when a supercell appeared right in front of my window. I was very happy because I had never seen a supercell so close by and I could clearly see the wallcloud which was above the farmlands of the peninsula (which is also called Sint Philipsland). The inflow tail came right over the village. When it was above me, I could feel that the air was sucked into the thunderstorm.
When I first reported in the mean thunderstorm thread that I had seen a supercell, some people didn't believe me (perhaps I shouldn't have called it a 'beast of a supercell', but I was very enthusiast), even after I posted some photos. There are several arguments which make it plausible that it was a supercell.
1. DLS was 20-25 m/s during the lifetime of the thunderstorm
2. My brothers car was (a little bit) damaged by 3 cm hail (while the CAPE was only around 500 J/kg)
3. The thunderstorm deviated to the right.
4. It showed a V-notch.
5. The anvil height of this thunderstorm was 8 km while the anvil height of other thunderstorm was barely 7 km. Moreover it showed a 2 km overshooting top reaching 10 km during its whole life.
Except for argument two a thunderstorm in Overijssel showed the same behavior. I suggested that this thunderstorm could be a supercell too, but somebody said: "Robert not every thunderstorm is a supercell" (that's right but he didn't have any reasons why the thunderstorm in Overijssel wasn't a supercell).
The Dutch weather radar archive can be found on http://buienradar.nl/historie.aspx. The date is 5 august 2012 and the supercell appears at 15:00 in the south of Zeeland. Tick 'toon bliksem indien aanwezig' to see lightning. Click on 'Ophalen' to get the requested image. Click on 'Volgend beeld' to see the next image. Click on 'Vorig beeld' to see the previous image. You can see the other suspected supercell in Overijssel too around that time. I think there are more thunderstorms that could be supercells but I'm pretty sure that these two thunderstorms are supercells.
The supercell that developed in Zeeland caused a lot of flooding in Rotterdam. Later a new supercell arised to the right of the old supercell and the new supercell killed the old supercell (or the old supercell killed the new thunderstorm and continued) The new supercell (or the old supercell) caused flooding in Utrecht and Hilversum and a brief tornado which caused damage was reported in Putten.
I made some photos from out of my window (unfortunately my parents didn't let me go to the wallcloud above the farmlands) and posted some of them on https://www.onweer-online.nl/forum/topic/35282/ontwikkeling-van-een-wallcloud/. In this thread I have posted some photos, a radar image of the supercell shortly after the last photo was taken and a photo of a wall cloud in Australia (not mine) to show them how I imagine a wall cloud. I've called the thread 'Development of a wall cloud' because it shows (in my opinion) the development of a wall cloud. At first I didn't see any wallcloud (or it could be hidden between the inflow tail or a tree), a little bit later the wallcloud appeared and shorty after the wallcloud got gradually obscured by a rain curtain. Some people didn't believe that it was a wallcloud. Somebody said that the tail cloud was on the wrong place but that person didn't know the difference between a tail cloud and a beaver tail. He also said that a wall cloud was a type of arcus.
So the most disappointing thing is that some people just say: "You are not right" without any reasons and not knowing what they're talking about. This has occured several times. They only believe that it is a supercell when you come up with spectacular photos or when your name is Reed Timmer.
So guys I have four questions:
1. Is this a supercell and do my photos show a wallcloud?
The updraft was on the southeastern side of the thunderstorm and the wallcloud was obscured by the rain. The radar also showed a heavy rain core and the thunderstorm caused floodings. So:
2. Is this a HP supercell?
3. Is a wall cloud an type of arcus? I don't think so but what do you think?
4. Do you mind if I post more storm reports on Stormtrack when I get to see more supercells in the Netherlands?
I look forward to the reactions.
Robert
In the Netherlands we have a few tens of supercells every year so they are quite rare. Since I'm not yet allowed to drive a car I can't go to the storms so the storms have to come to me. I had always wanted to see a supercell above my home village. Last Sunday I got lucky when a supercell appeared right in front of my window. I was very happy because I had never seen a supercell so close by and I could clearly see the wallcloud which was above the farmlands of the peninsula (which is also called Sint Philipsland). The inflow tail came right over the village. When it was above me, I could feel that the air was sucked into the thunderstorm.
When I first reported in the mean thunderstorm thread that I had seen a supercell, some people didn't believe me (perhaps I shouldn't have called it a 'beast of a supercell', but I was very enthusiast), even after I posted some photos. There are several arguments which make it plausible that it was a supercell.
1. DLS was 20-25 m/s during the lifetime of the thunderstorm
2. My brothers car was (a little bit) damaged by 3 cm hail (while the CAPE was only around 500 J/kg)
3. The thunderstorm deviated to the right.
4. It showed a V-notch.
5. The anvil height of this thunderstorm was 8 km while the anvil height of other thunderstorm was barely 7 km. Moreover it showed a 2 km overshooting top reaching 10 km during its whole life.
Except for argument two a thunderstorm in Overijssel showed the same behavior. I suggested that this thunderstorm could be a supercell too, but somebody said: "Robert not every thunderstorm is a supercell" (that's right but he didn't have any reasons why the thunderstorm in Overijssel wasn't a supercell).
The Dutch weather radar archive can be found on http://buienradar.nl/historie.aspx. The date is 5 august 2012 and the supercell appears at 15:00 in the south of Zeeland. Tick 'toon bliksem indien aanwezig' to see lightning. Click on 'Ophalen' to get the requested image. Click on 'Volgend beeld' to see the next image. Click on 'Vorig beeld' to see the previous image. You can see the other suspected supercell in Overijssel too around that time. I think there are more thunderstorms that could be supercells but I'm pretty sure that these two thunderstorms are supercells.
The supercell that developed in Zeeland caused a lot of flooding in Rotterdam. Later a new supercell arised to the right of the old supercell and the new supercell killed the old supercell (or the old supercell killed the new thunderstorm and continued) The new supercell (or the old supercell) caused flooding in Utrecht and Hilversum and a brief tornado which caused damage was reported in Putten.
I made some photos from out of my window (unfortunately my parents didn't let me go to the wallcloud above the farmlands) and posted some of them on https://www.onweer-online.nl/forum/topic/35282/ontwikkeling-van-een-wallcloud/. In this thread I have posted some photos, a radar image of the supercell shortly after the last photo was taken and a photo of a wall cloud in Australia (not mine) to show them how I imagine a wall cloud. I've called the thread 'Development of a wall cloud' because it shows (in my opinion) the development of a wall cloud. At first I didn't see any wallcloud (or it could be hidden between the inflow tail or a tree), a little bit later the wallcloud appeared and shorty after the wallcloud got gradually obscured by a rain curtain. Some people didn't believe that it was a wallcloud. Somebody said that the tail cloud was on the wrong place but that person didn't know the difference between a tail cloud and a beaver tail. He also said that a wall cloud was a type of arcus.
So the most disappointing thing is that some people just say: "You are not right" without any reasons and not knowing what they're talking about. This has occured several times. They only believe that it is a supercell when you come up with spectacular photos or when your name is Reed Timmer.
So guys I have four questions:
1. Is this a supercell and do my photos show a wallcloud?
The updraft was on the southeastern side of the thunderstorm and the wallcloud was obscured by the rain. The radar also showed a heavy rain core and the thunderstorm caused floodings. So:
2. Is this a HP supercell?
3. Is a wall cloud an type of arcus? I don't think so but what do you think?
4. Do you mind if I post more storm reports on Stormtrack when I get to see more supercells in the Netherlands?
I look forward to the reactions.
Robert
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