Strong tornado in Italy

[Andrea Griffa]

http://www.meteosicilia.it/tromba.pdf

That's not very common in Italy, guys...Usually tornadoes are less strong than this. This is a strong mesocyclonic tornado that hit a rural city in Sicily (Italy island), with RFD and clear slot. I really don't believe. .Note the big and terrifying debris!

Synoptic condition was a well uniformed cape zone with 2000J/Kg of MLCAPE associated with 300-350m2/s2 of storm relative helicity.
From bispectral satellite you can see a good convection with a clear supercell with an evident overshooting top.

http://digilander.libero.it/andreblu81/Tornado%203.jpg

 

[Mike Smith]

Mamma Mia!!

 

[Andrea Griffa]

Originally posted by Mike Smith
Mamma Mia!!

:wink: :lol: :lol:

 

[Andy Wehrle]

THERE IS A HIGH RISK OF SVR TSTMS...in Italy

Andrea, do you know anything about this?

On August 29, 2003, The European Storm Forecast Experiment ( http://www.estofex.org ), an outfit which issues SPC-style convective outlooks for Europe, placed parts of northern Italy under a high risk of severe thunderstorms ( http://www.fys.ruu.nl/~ttu/estofex/outlook...08291029up.html ). I cannot find any information anywhere about whether or not the anticipated outbreak actually occured, and any notable tornadoes or damaging wind events that might have been associated with it.

Do you know if this rare European high-risk day verified, or if not, where I might be able to find out?

 

[Andrea Griffa]

Re: THERE IS A HIGH RISK OF SVR TSTMS...in Italy

Originally posted by Andy Wehrle
Andrea, do you know anything about this?

On August 29, 2003, The European Storm Forecast Experiment ( http://www.estofex.org ), an outfit which issues SPC-style convective outlooks for Europe, placed parts of northern Italy under a high risk of severe thunderstorms ( http://www.fys.ruu.nl/~ttu/estofex/outlook...08291029up.html ). I cannot find any information anywhere about whether or not the anticipated outbreak actually occured, and any notable tornadoes or damaging wind events that might have been associated with it.

Do you know if this rare European high-risk day verified, or if not, where I might be able to find out?

Hi Andy
I made a study about the event also with the help of Jonathan Davies, Gene Moore and others.
Parameters was incredible in Northern Italy that day but convection that developed was supercellular in only a limited part of northern Italy where a nice supercell produced a strong F2 tornado.
The climate of Italy is very very complicated: if a low pressure develope in the extreme western part of Northern italy, South-Southwestern wind that develops, are so much dry and destroy the rich in cape zone(adiabatic compressure). For this reason in the other part of Northern Italy outbreak didn't develop because the low pressure system was very strong and and formed in the wrong zone!!

I remember helicity was 500m2/s2 and cape was 3000J/Kg: infact Estofex issued an High risk...But Estofex forecasters couldn't know our microclimate.

This is my article (in italian) with some photoes of the tornado(when it was rope):

http://storms.meteonetwork.it/modules/news....php?storyid=56

 

[Andrea Griffa]

Originally posted by Andrea Griffa
http://www.meteosicilia.it/tromba.pdf

That's not very common in Italy, guys...Usually tornadoes are less strong than this. This is a strong mesocyclonic tornado that hit a rural city in Sicily (Italy island), with RFD and clear slot. I really don't believe. .Note the big and terrifying debris!

Synoptic condition was a well uniformed cape zone with 2000J/Kg of MLCAPE associated with 300-350m2/s2 of storm relative helicity.
From bispectral satellite you can see a good convection with a clear supercell with an evident overshooting top.

I've known about another strong tornado that developed on the same day in Malta Island(South of Italy)...See this:

[Broken External Image]:http://www.maltaweather.org/tornadonadur13nov2004_2.jpg

That day was crazy :shock:

 

[Andy Wehrle]

Thanks Andrea! That's exactly the kind of information I was looking for!

 

[Andrea Griffa]

Originally posted by Andy Wehrle
Thanks Andrea! That's exactly the kind of information I was looking for!

It's a pleasure!

 

[Jimmy Deguara]

Hi all,

I visited my relatives in Malta 1996 and was interested in the troughs that developed in the morning before the ridging set over Malta. You would then note severe storms over Italy on the news that evening. Would have been interesting if that type of an event occurred whilst over there that year.

Now it seems the Sicily event may have been a separate one than the Malta event. But I wonder if the event in Tunisia was related to the Malta event.

Regards,

Jimmy Deguara

 

[Andy Wehrle]

Re: THERE IS A HIGH RISK OF SVR TSTMS...in Italy

Parameters was incredible in Northern Italy that day but convection that developed was supercellular in only a limited part of northern Italy where a nice supercell produced a strong F2 tornado.
The climate of Italy is very very complicated: if a low pressure develope in the extreme western part of Northern italy, South-Southwestern wind that develops, are so much dry and destroy the rich in cape zone(adiabatic compressure). For this reason in the other part of Northern Italy outbreak didn't develop because the low pressure system was very strong and and formed in the wrong zone!!

I remember helicity was 500m2/s2 and cape was 3000J/Kg: infact Estofex issued an High risk...But Estofex forecasters couldn't know our microclimate.

This is my article (in italian) with some photoes of the tornado(when it was rope):

http://storms.meteonetwork.it/modules/news/article.php?storyid=56

Andrea, I have decided to include this ESTOFEX high risk (which I am fairly certain is the only time they have issued one in their history) in my high risk list at http://sphs.angeltowns.net/insanity/highrisk.html

I will include a link to your study page, but I also would like to include your explanation as I quoted it above. I just want to make sure this is all right with you.

 

[Andrea Griffa]

Re: THERE IS A HIGH RISK OF SVR TSTMS...in Italy

Parameters was incredible in Northern Italy that day but convection that developed was supercellular in only a limited part of northern Italy where a nice supercell produced a strong F2 tornado.
The climate of Italy is very very complicated: if a low pressure develope in the extreme western part of Northern italy, South-Southwestern wind that develops, are so much dry and destroy the rich in cape zone(adiabatic compressure). For this reason in the other part of Northern Italy outbreak didn't develop because the low pressure system was very strong and and formed in the wrong zone!!

I remember helicity was 500m2/s2 and cape was 3000J/Kg: infact Estofex issued an High risk...But Estofex forecasters couldn't know our microclimate.

This is my article (in italian) with some photoes of the tornado(when it was rope):

http://storms.meteonetwork.it/modules/news/article.php?storyid=56

Andrea, I have decided to include this ESTOFEX high risk (which I am fairly certain is the only time they have issued one in their history) in my high risk list at http://sphs.angeltowns.net/insanity/highrisk.html

I will include a link to your study page, but I also would like to include your explanation as I quoted it above. I just want to make sure this is all right with you.

Yes, Andy I see Estofex from the biginning and I don't remember another high risk issued in Europe.

About the explanation you could write that on 29th august in North Italy occurred the condition for a tornado outbreak. We had a moderate unstable air-mass (1500-3000 J/kg) over a good part of Po-Valley and a strong low level shear with east-southeasterly surface winds and 850mb south-southwesterly winds. Covective forecast showed helicity values of 500 m2/s2 and more than 60kt of deep-layer shear.
But the climate of Italy is very very complicated: if cold front impacts against Alps mountains with a too much northwesterly oriented position instead of a westerly oriented position, the low pressure developes in the extreme western part of Northern italy, and generates so much dry winds at surface and destroy the rich in cape zone (adiabatic compressure). For this reason in the other part of Northern Italy outbreak didn't develop because the low pressure system was very strong and and formed in the wrong zone!!
Anyway parameters was incredible in Northern Italy that day but convection that developed was supercellular in only a limited part of northern Italy where a nice supercell produced a strong F2 tornado.


Andy, it can be good for you?