Flying EGLL-WSSS today, I encountered a rain storm over southern Thailand. I managed to skirt around the biggest storm and continued my journey successfully.

 

I had wondered how severe was each of the radar returns indicated. How deadly is a red return?

 

I found an article that others may find interesting.

 

Cheers, Richard

 

 

How deadly is a red return?

 

Not at all.

 

The return itself simply means "a bunch of rain."  It's the issues that usually surround "a bunch of rain" that make storms deadly - or more appropriate: dangerous.  The more dangerous parts are often associated (but not always associated) turbulence, and up/downdrafts.  That's why the WX+T mode is a little more revealing.

 

It's entirely possible, however, to have a whole bunch of rain in completely still air.  Flying through that only risks a flameout, but most modern planes can handle that without flaming out.

Hi Richard, flight into the red can leave you dead. If various shades of green were displayed, I would avoid the darkest green whenever possible and avoid yellow at all cost. A friend of mine barely survived something that was masked by yellow returns, his Citation lost 20,000 ft, radome gone, leading edges severely damaged and it was so loud the two up front couldn't hear each other on their headsets. He survived only because his engines survived. It makes an impression.

Hi Kyle,

You are, as usual, quite correct. Thanks for your positive reply :im Not Worthy:

 

Hi Dan,

Most interesting story. I hope that I never have a situation even half as bad.

 

Cheers to you both,

Hej

 

As Dan said avoid even the darker greens...

 

On a real world flight I was serving on a few weeks ago from EGLL to KMIA we ran into some lively weather just before we started our descent north of Freeport. We had a pretty smooth flight with a some 'bumpy stuff' over New Jersey. The Captain had briefed me around 15 mins before we reached ToD about some "building thunderstorms both on descent and maybe on finals also". The Capt showed me the weather radar on our B772 and it showed a mixture of colours, lots of greens (light and dark) and small dots of red and yellows. There were larger red dots to the left and right of the screen which you could clearly see out of the flight deck windows. On exiting the flight deck and around 7 mins from ToD the Capt turned on the seatbelt sign as he and I had agreed. This was so our passengers had time to secure their areas of the cabin for landing / suddenly realise they had not filled out their arrival documents even though we had been asking them to do so for well over an hour (that happens on every flight - humans and paperwork stop getting along above 10,000ft). :unsure:

 

As I heard the engines roll back to idle we started to get a slight choppy turbulence which grew over the next five minutes to a level were even I found it difficult to walk down the aisle. The Capt then made an announcement which I had only heard twice before "crew return to galleys and secure" (crew speech for stop serving, return everything that could cause injury to the galleys and cabin crew to seat down if possible).

 

I returned to the flight deck to collect some information from the first officer and I was amazed to what I saw on the weather radar and outside the flight deck windows. The small dots of yellow were much bigger and had red dots in the middle of them. It looked as if the dots had almost joined up (I don't know if they had or not). The Captain did point out a cell which we had discussed before ToD saying that it was now way above what our crusing cruising alt had been. While sat on a jump seat on the flight deck I noticed a number of cells which grew in front of my eyes. After another few minutes the small yellow dots had gone and we were left with three main 'returns'. All three were big patches of red which were surrounded by areas of yellow and dark greens. You could hardly see any area of black (meaning no return) just light green where the black should be.

 

It makes me wonder how pilots ever flow without weather radar! One thing that this real life event showed is how quickly these storms can build and the fact that they can build around your flight plan very quickly limiting your options. It was clear to see that the pilots on my flight were having to keep a very close eye on the weather radar and trying to predict how the cells were going to develop both individually or as a kinda merged super cell.

 

Has anyone ever heard of a number of smaller cells merging into one larger more powerful cell? (I guess a number of green returns merging into large yellows or red returns/cells)? If you have (either in real world flying or on FSX) how long did the process take?

 

Our flight after four ish minutes of heavy turbulence seemed to clear the worst of the weather and the radar screens returned to the normal look of lots of green dots, with the odd small red dot mixed in... We did end up holding for around 20 minutes due to a thunderstorm rattling through the Miami Airport area, something that seems to happen a lot whenever I fly to Miami. :mad:

 

I find myself wanting to go closer to the red stuff on my FSX Boeing 77W's weather radar something my close friend who is a real world Captain reminded me I am meant to do the opposite! (I guess thats why he fly's the aircraft while I serve the tea and coffee's )

 

Regards

 

Kimberly Richmond-Jones B)

Hi Kimberley,

Well done in sharing some real world experiences for us.

Cheers, Richard

Hej

 

As Dan said avoid even the darker greens...

 

One thing that this real life event showed is how quickly these storms can build and the fact that they can build around your flight plan very quickly limiting your options.

Exactly right, well said!

 

Nice read Kimberly :-)

Not at all.

 

The return itself simply means "a bunch of rain."  It's the issues that usually surround "a bunch of rain" that make storms deadly - or more appropriate: dangerous.  The more dangerous parts are often associated (but not always associated) turbulence, and up/downdrafts.  That's why the WX+T mode is a little more revealing.

 

Huh....not deadly?

 

You are also not mentioning the two MOST hazourdous elements of a thunderstorm or CB:

- icing.....(Air France crash)

- Hail stones the size of tennisballs! (possible up to even 30nm next to the CB in clear skies!)

 

Sounds pretty deadly to me.

 

 

If you are talking about the red radar returns that are often present in say Asia, yes they are just huge area of heavy heavy rain. (as you mentioned......flame out possible)

 

CBs have a definate roundish shape. They typically have an edge where they begin (green) and a center (red).

Large areas of light/moderate/heavy rain are irregular in shape, cover large areas and are just green/yellow/red everywhere depending on intensity (no red circular center)

 

 

Has anyone ever heard of a number of smaller cells merging into one larger more powerful cell? (I guess a number of green returns merging into large yellows or red returns/cells)? If you have (either in real world flying or on FSX) how long did the process take?

 

Yes and no.

 

There was a pretty terrible movie about it a while back called "The Perfect Storm."

 

Spoiler alert:  All the people you grow to like and pull for the whole movie end up succumbing to aforementioned storm.

 

In all seriousness, though, when storm systems clash (merge/collide/combine), it can get pretty ugly.  What I'm betting you were seeing, though, was the radar only slicing through the obvious, or relevant bits of the storm while at altitude, and then showing the base of the storm as you got lower.  Think of it like the terrain map function in peaks mode.  Thunderstorms have a lot of vertical build up, but the bases are usually thicker at the bottom.  With that, you'll see a bunch of towers of clouds, but at the bottom the clouds are usually merged as one larger system (and if not, the bases are, again, usually a lot larger than the towers).  That being said, if you shoot radar through the towers, all you're going to catch is a slice through each tower, which will make each tower look isolated.  As you descend, the radar slices lower into the clouds, yielding a more "solid" picture.

 

In a similar vein, you could adjust the tilt instead of altitude to achieve the same effect, and I'll use a graphic from Boeing:

 

Source: Boeing.com

 

The image depicts two different tilt angles.  The upper tilt angle, essentially looking straight ahead, would only show green returns.  More specifically, it would show three green bands: a narrow one near you, followed by nothing, a larger band in the middle, followed by nothing, and a thick band farthest away (assuming no signal degradation or "shadowing" through the bands here).  The lower tilt angle (the one aimed down into the lower part of the storm) would show solid returns of rain in the green and yellow bands.

 

I'm imagining you were seeing similar as a matter of altitude and the angles of the slices of the radar beam through the system.

 

Just my thought, though!  Nice story!

Huh....not deadly?

You are also not mentioning the two MOST hazourdous elements of a thunderstorm or CB:
- icing.....(Air France crash)
- Hail stones the size of tennisballs! (possible up to even 30nm next to the CB in clear skies!)

Sounds pretty deadly to me.


If you are talking about the red radar returns that are often present in say Asia, yes they are just huge area of heavy heavy rain. (as you mentioned......flame out possible)

CBs have a definate roundish shape. They typically have an edge where they begin (green) and a center (red).
Large areas of light/moderate/heavy rain are irregular in shape, cover large areas and are just green/yellow/red everywhere depending on intensity (no red circular center)

 

Please, carefully re-read what I wrote Rob  :wink:

 

You can very clearly see I started out on a very conceptual level: returns are rain.

 

A red return simply shows a ton of reflection, specifically from precipitation.  That is all.  I could point a weather radar as a docile layer of stratus clouds that are dumping loads upon loads of rain on the ground, and I could fly through that all day and conceptually be just fine.

 

From there, though, I conceded the point that red returns are normally associated with thunderstorms, which, by all means, we should be avoiding.

 

 

 

It's like icing.  Moisture can cause airframe icing, but it is not dangerous by itself.  It's the cold air being associated with that moisture that causes the issue.

 

Red returns are the water.  In and of itself, it is not at all dangerous.  The dangerous part is the other part of the equation: the cold.

 

Again, that isn't to say "go blasting through red cells," because more often than not, the reason there's that much rain is that there was enough convective activity to allow it to build up that much, but again, at its base: red just means "a lot of rain."

 

...it's what's associated with that "lot of rain" that's the issue.

Hmmmmmm......I will give you the benefit of the doubt this time Kyle ;-)

Hmmmmmm......I will give you the benefit of the doubt this time Kyle ;-)

 

haha - appreciated.  So much so that your DC Brau is on me next time you're in G'town.

Don't give him the benefit of the doubt, come down on him like a ton of bricks.

 

It's good for him. :smile:

 

Don't give him an inch, not even a milimicron.

 

 

Don't give him the benefit of the doubt, come down on him like a ton of bricks.

 

It's good for him. :smile:

 

Don't give him an inch, not even a milimicron.

 

haha - oddly very accurate.

I believe linking to outside images here is forbidden by AVSIM ToS, however if you google EasyJet + 737 + hail you will find some interesting pictures. I remember reading somewhere (this was years ago) that this happened when flying around a cell actually, not through one, which would coincide with Rob's post above.

 

Dan's post remind me of a story from a friend of mine flying back then for the venezuelan air force about his encounter with a tropical storm around margarita island in the caribbean (SVMG). They had no choice but to fly in the area, careful not to go through anything "too green" in the scope (it was a 1990s C-130 without advanced avionics) and yet entered through a nasty "wall of hail" (according to his story)  several miles lateral to a big CB formation, and he would tell you how he remembers like it was "yesterday" all the vibrations and the noise in the cockpit during the minutes that he had to fly through it. The aircraft suffered a few scratches but nothing close to the EasyJet 737 above.

 

Btw Kimberly, that was an interesting read, thank you for sharing. I agree with you on the weather in Miami, two out of the three go arounds in my life have been in Miami due to weather! :-/  (the third one was me as a pilot-non-flying in a Cessna 152 after a flock of birds appeared out of nowhere during a very short final).

I remember helping a nearby flight school ferry their airplanes to keep them safe from an oncoming hurricane. This went well, so I decided to fly out to my next assignment the next day. Didn't seem like a good idea to fly so much after having ferried planes all day to fly out immediately. Well, it seemed like a good idea at the time ...

 

The next day when I flew out (in a Citation II), the storm decided to take a turn, and worse, it picked up speed all of a sudden.

 

Worst. Flight. Ever.

 

It was more like Kyle said, though. You always tilt down to see what's coming up. Still, I've never seen so much ###### build up in front of me. We decided to turn back and wait this one out. After all, don't let gethomeitis get to you as it will kill you!

 

Agreed, this was when a hurricane was in the area. Even so, when you ask how fast things can build up, this can be in a matter of minutes, and you don't need a hurricane for it either.