bin bedingt durch meine Tätigkeit beim ESSL in der ESWD-Datenbank auf einen recht unklaren "Tornado-Fall" gekommen.
Befindet sich zwar nicht in Österreich sondern in De Punt, Niederlande, aber ich denke, dieser Fall kann lehrreich sein und ich hoffe auf die fachliche Meinung unserer Experten, da ich sonst auch nicht weiß, ob ich diesen Fall tatsächlich als Tornado, oder doch nur Funnel Cloud führen soll.
Hier sämtliche Fotographien:
https://www.dropbox.com/sh/djab11kzac7y5uf/cWWrrE_6bf
Der "Tornado" (?) selbst:
http://www.imagebanana.com/view/ne498vjc/SAM_1216.JPG
http://www.imagebanana.com/view/k8tesysb/SAM_1219.JPG
http://www.imagebanana.com/view/2nc69027/SAM_1220.JPG
http://www.imagebanana.com/view/995f9inu/SAM_1222.JPG
Schadenspfad:
http://www.imagebanana.com/view/5x7ccke ... 095353.jpg
http://www.imagebanana.com/view/75896ef ... 112853.jpg
http://www.imagebanana.com/view/d6lw23t ... 113817.jpg
http://www.imagebanana.com/view/ka6guy0 ... 113245.jpg
http://www.imagebanana.com/view/stdytve ... 094603.jpg
Dazu wurde mir Folgendes mitgeteilt (gekürztes englisches Original, sinngemäß):
-----
There is an entry for 21-08-2012 named "De Punt". I have confirmed that at
least 2 trees were uprooted, and thick branches (30cm) were broken of.
Also a large branch (10cm) was thrown; it was hanging ~1,5m above the ground
in some fegitation. I guess that to be high end EF0 damage, in stead of the
low end F1 I thought it was earlier?
This is the report now:
De Punt
Next to the Highway, between two exits (one to Glimmen, the other towards
Zuidlaren) Drenthe
Netherlands (53.12 N, 6.60 E) (+/- 1 km)
21-08-2012 (Tuesday) 17:15 UTC
[...]
In the mean time, you could check out radar imagery searchable via
http://www.buienradar.nl/radararchief" onclick="window.open(this.href);return false;
I'm sorry for the fact that another language isn't supported.
Datum=date tijdstip=time
Ophalen=confirm/go
Vorig/volgend is very close to German
I believe there is a sequence of images from ~16.00-18.30.
You would see an isolated mini-supercell, slightly hook-shaped. Clearly
discernable is the deviant storm motion and its cyclic structures.
[...]
--> Dazu meine erste Einschätzung:
Hi [...],
I have now checked your material for tornado signatures / tornado damage.
https://www.dropbox.com/sh/djab11kzac7y ... 112853.jpg" onclick="window.open(this.href);return false;
--> Looks like this part of the tree was uprooted a longer time before the storm (already quite brown and dry leaves).
https://www.dropbox.com/sh/djab11kzac7y ... 095353.jpg" onclick="window.open(this.href);return false;
--> This branch has definitely not been broken by wind foces but was rather cutted by humans (chain saw).
https://www.dropbox.com/sh/djab11kzac7y ... 113821.jpg" onclick="window.open(this.href);return false;
--> The grass could be an indicator, yes - but it seems quite rainy / wet so the grass could also have got laid down due to the water.
https://www.dropbox.com/sh/djab11kzac7y ... -Groningen" onclick="window.open(this.href);return false;
--> Based on your cloud photos I can identify a wall cloud, yes - but the possible tornado does not stay in contact with that wall cloud but is rather quite a distance away from it to the left.
https://www.dropbox.com/sh/djab11kzac7y ... M_1220.JPG" onclick="window.open(this.href);return false;
--> This is the only photo for me where I would say that rotation had been present, especially when you put on more contrast into the photo. But over all we can not be sure wheter there had been grund contact or not - so I suggest - and will do so - to classify your observation as a funnel cloud. We can only classify tornadoes as tornados in the ESWD, when we are really sure about it. Otherwise funnel cloud entries are the more appreciate way to hold such a dataset entry in the database.
[...]
---> Und die bisher letzte Antwort:
Hey Thomas,
[...]
Thanks for the reply. I probably failed to state that the pictures were
taken almost a month after the tornado touched down (fail on my end there).
So maybe that could explain the brownish leaves? Also, the supercell was
cycling through occlusions, so the rather big wallcloud was initiated by a
new updrought.
It seems to me a logic point that there is more constriction of the
different airmasses around the low-level mesocyclone stretching it downward
into a funnel shape. Altough it was visible to the eye as a spinup from
half-way the ground and cloud base upward.
The 'chainsawed' branch was hanging in the bushes at a height of
approximately 1,5 meters. I don't think it's likely someone threw it there
leaves-end first. In one of my pictures there is a black blob visible around
the tornado, but it could be a bird.
Hope you can help me out here.
Regards,
[...]
An dieser Stelle seit nun also bitte ihr gefragt! Was meint ihr zu diesem Fotoaufnahmen von Gewölk und Schäden? Bitte um euer Mitwirken, danke!
Liebe Grüße
Thomas
