Sabena 690 From , joined Dec 1969, posts, RR: Posted (9 years 11 months 2 weeks 5 days 9 hours ago) and read 1734 times:
Hi all,
On sundaymorning (around 9am), 10 minuts before heavy thunderstorms, I took some pictures of a strange phenomen of nature, which is called in Dutch 'rolwolken' (role clouds or so in English).
Can anybody give me some more info about this? Below are some pictures (thanks to forum member Turbotrent for the webspace):
Mbmbos From United States of America, joined May 2000, 2561 posts, RR: 1 Reply 3, posted (9 years 11 months 2 weeks 5 days 6 hours ago) and read 1517 times:
Talked to the in-laws last night, who live in Achel, Belgium, near Eindhoven, NL. They said this was quite a righteous storm.
KROC From United States of America, joined May 2000, 19737 posts, RR: 76 Reply 5, posted (9 years 11 months 2 weeks 5 days 6 hours ago) and read 1512 times:
It is hard to tell from the picture, but if I had to guess, I would say that it appears to be a break in the lower level stratus layer, and the light showing is from an altostratus layer above.
"Never tell anybody outside the family what you're thinking again"
Sabena 690 From , joined Dec 1969, posts, RR: Reply 6, posted (9 years 11 months 2 weeks 5 days 6 hours ago) and read 1503 times:
LOL Dan!
Following forum member 744rules, they said something on TV about this, and this phenomen happens when warm clouds go upstairs, and come in collission with cold clouds coming downstairs.
Anyway, still very strange...
Yyz717 - no idea if the temperature decreased suddenly. I quickly went back inside, it was raining too heavy.
Mbmbos: it was indeed a very heavy storm. There even was a green shine in the dark clouds on a sudden moment which means heavy thunderstorms.
CPH-R From Denmark, joined May 2001, 5745 posts, RR: 4 Reply 7, posted (9 years 11 months 2 weeks 5 days 6 hours ago) and read 1503 times:
It was pretty bad uphere too, though I was only exposed to the light side of it. Some places in Jutland, they had around 30-40 mm of rain in 1-2 hours!
KROC From United States of America, joined May 2000, 19737 posts, RR: 76 Reply 9, posted (9 years 11 months 2 weeks 5 days 5 hours ago) and read 1489 times:
From the middle picture, it looks as if there is a split in the low level stratus, maybe caused by winds aloft, 2 different air masses etc. Hence my guess. Like I said though, hard to venture a guess from the pics.
"Never tell anybody outside the family what you're thinking again"
Stratofish From Germany, joined Sep 2001, 1011 posts, RR: 6 Reply 10, posted (9 years 11 months 2 weeks 5 days 2 hours ago) and read 1460 times:
Did it look like they were rotating a bit and moving over you?
If so they were indeed roll couds. They happen mostly in the downdraft area of a thunderstorm. Often this is the area right before the precipitation/raining one. Roll clouds CAN be an indication of high wind gusts and turbulences.
Sometimes they can happen along with the rear flank downdraft. AFAIK, roll clouds and shelf clouds are a clear sign of a supercell, so you better seek shelter if you see them. Although I have never seen a roll cloud yet myself .
Stratofish
[Edit:] Apparantely they can travel long distances: http://www.dropbears.com/brough/glory89.htm
I can´t find my meteorology book at the moment so that´s pretty much all I know about these phenomena.
AA61hvy From United States of America, joined Nov 1999, 13975 posts, RR: 59 Reply 11, posted (9 years 11 months 2 weeks 5 days ago) and read 1424 times:
Maybe Doc Brown and Marty went back in time again...?
Seb146 From United States of America, joined Nov 1999, 9818 posts, RR: 17 Reply 12, posted (9 years 11 months 2 weeks 4 days 23 hours ago) and read 1415 times:
Cool light pole, too!
Sometimes when I have gone to the beach on the Columbia River just west of here, I have seen clouds similar to this. Kinda freaky but cool to watch.
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