8 hours ago, Marenostrum said:

I did some calculation...in the situation that I described it meant do deviate the course toward the upwind side of the right cell, then to fly around it staying at least 20NM away then to reconnect the original flight path.....in other words to extend the flight path of about 100 NM or more !!!!

This is routine during the spring/summer storm season in the US.  For example, I'm just down the coast 200 nm from Houston and there have been days when I went North of College Station to get there, adding at least 100 nm to a 200 nm trip. 

9 hours ago, Marenostrum said:

I did some calculation...in the situation that I described it meant do deviate the course toward the upwind side of the right cell, then to fly around it staying at least 20NM away then to reconnect the original flight path.....in other words to extend the flight path of about 100 NM or more !!!!

Yup... and that's why you checked the SigWx and other weather charts for your route beforehand and added some extra fuel, right? 😋

15 hours ago, downscc said:

This is routine during the spring/summer storm season in the US.  For example, I'm just down the coast 200 nm from Houston and there have been days when I went North of College Station to get there, adding at least 100 nm to a 200 nm trip.

I see you are used to fly in a zone that is also hit by twisters..is it?

How are those cells seen by the cruising altitude?

What SigWx says and what to do?

14 hours ago, skelsey said:

Yup... and that's why you checked the SigWx and other weather charts for your route beforehand and added some extra fuel, right? 😋

Sure 🙂

 

8 hours ago, Marenostrum said:

How are those cells seen by the cruising altitude?

You cannot tell if a storm has or will spawn a tornado by looking at it in the air from an airplane.  Tornadoes do seem to come from a storm system that has multiple embedded CB but it's not true that such a system is required for or will always spawn tornadoes.

You can often visually tell if a storm is rotating by horizontal banding, called striations, that appear on the main updraft.  Some extreme examples on this image search :

https://www.google.com/search?hl=en-US&biw=360&bih=255&tbm=isch&sa=1&ei=hlQ2W-ivEdLB0PEPzviSkA8&q=supercell+striations+aerial&oq=supercell+striations+aerial&gs_l=mobile-gws-wiz-img.3...0.0..6461...0....0.0.......0.1OQiLagx4wQ%3D

I have some more "typical" weak supercell (rotating thunderstorm) photos on my ipad from just last week, I think.  I'll see what I can find.

Most supercells do not produce tornados, but they're all severe enough to rip a jet into little pieces and spit them out the top, if you happen to wander into the main updraft. 

There are some visual indications of tornadogenesis, but you have to know what you're looking for.  Things like rear flank downdraft coupled with a rapidly forming clear slot, a collapsing then recycling overshooting top etc... Not stuff the average pilot would know about.  I only know this because atmospheric science is my background and I spotted/chased for the National Weather Service in the Midwest USA for years... In other words, I'm a weather nerd ;-). 

19 minutes ago, Stearmandriver said:

Some extreme examples on this image search :

 

The pictures attached are very scary!!!! I For sure it is not necessary to browse the SOP to stay away from them more than 50nm. 

Some of them in the pictures are also very wide, tall and, if it is not enough, twisted ...to fly around such a large beast it could be a long way.

I suppose that inside them you find a mix of all the scary situations: high speed wind variation with rapid variation in direction, ascending and descending currents, hail, heavy rain...
I have read that they can build inside also vertical windshear  at high altitude rotating updraft!! (I knew about the descending windshear at low altitude dangerous in the approach phase, not vertical windshear dangerous at a cruising FL).

If I were a pilot facing a beast like that...I would like to be in a sim!

 

 

1 hour ago, downscc said:

You cannot tell if a storm has or will spawn a tornado by looking at it in the air from an airplane.  Tornadoes do seem to come from a storm system that has multiple embedded CB but it's not true that such a system is required for or will always spawn tornadoes.

Interesting...

In any case from the pilot point of view, the key point is if these types of cells can be flown over their top or if they are the kind of monster that climb up to over FL350 ... so you can just stay away and fly around.

2 hours ago, Stearmandriver said:

There are some visual indications of tornadogenesis, but you have to know what you're looking for.  Things like rear flank downdraft coupled with a rapidly forming clear slot, a collapsing then recycling overshooting top etc... Not stuff the average pilot would know about.  I only know this because atmospheric science is my background and I spotted/chased for the National Weather Service in the Midwest USA for years... In other words, I'm a weather nerd ;-). 

Fascinating. I flew by the storm that visited a tornado on Ft Worth ripping out windows from skyscrapers and didn't know it until I saw the news.  I was departing Dallas Redbird to the South so my route gave me a nice long view of it and I was glad I was heading away.  I lived in Norman OK for about four years and knew a few that worked at the National Storm Center... very sharp people, very dedicated.  As far as I'm concerned NOAA is one of the best branches of the unarmed government.

1 hour ago, Marenostrum said:

In any case from the pilot point of view, the key point is if these types of cells can be flown over their top or if they are the kind of monster that climb up to over FL350 ... so you can just stay away and fly around.

If you're talking about the big tornadic supercells, you aren't going over unless you're in a U2 ;-). These types of cells can top FL600; that's well into the stratosphere where weather isn't supposed to be able to reach, but these updrafts are powerful enough to bust through the cap of the tropopause. 

Over still might not be a great idea in something like a U2; these storms also produce two rare types of lightning called sprites and jets that extend upwards from the storm basically to space.  They seem to be the electrical field of the storm interacting with the ionosphere.  Probably no one knows if it's possible to be struck by them but I wouldn't be the one to test it lol. 

OK, sorry, I'll reign in the weather geekery. 

4 minutes ago, downscc said:

Fascinating. I flew by the storm that visited a tornado on Ft Worth ripping out windows from skyscrapers and didn't know it until I saw the news.  I was departing Dallas Redbird to the South so my route gave me a nice long view of it and I was glad I was heading away.  I lived in Norman OK for about four years and knew a few that worked at the National Storm Center... very sharp people, very dedicated.  As far as I'm concerned NOAA is one of the best branches of the unarmed government.

I remember when that happened in Dallas.  Datasets from that storm are still studied. 

The Norman folks are the best in the business. 

2 hours ago, Stearmandriver said:

 

OK, sorry, I'll reign in the weather geekery. 

Nulla di cui dispiacersi.....l'rgomento è molto interessante, forse molto noto  a molti piloti ma certamente non inutile da rinfrescare.

Avevo letto e visto anche alcuni documentari sui fulmini "verso l'alto" visibili dallo spazio. 
Molto interessante, spaventoso e affascite
Neanche io vorrei essere su un U2 o un SR71 per verificare la loro pericolosità!

2 hours ago, downscc said:

very sharp people, very dedicated. 

.... people running real risks...I have read an interesting report by NTSB about an almost crash during the a survey mission inside a hurricane!!