Pentrating Towering Cumulus Clouds

When in doubt, don't! The CU's wouldn't be towering if they did not contain
strong updrafts...and don't forget the strong downdrafts on the outside of
the "tower." I can remember being rolled 60 degrees one day when I decided
to fly close to, but not into, such a cloud. Depending on penetration
altitude versus freezing level, they also contain what I call "splat icing,"
which can coat your airplane with a glossy load in a few seconds...look for
that (or please, don't look for that) in the top one-third of the cloud.

Bottom line: Stay away. Might not be anything in there, but I'm no one to
take chances.

Bob Gardner

"O. Sami Saydjari" wrote in message
...
Thunderstorm season is up us. I get a little concerned when I see
towering cumulus clouds forming in my flight path because I know that
towering cumulus clouds can turn into thunderstorms.

1. Assuming that thunderstorms were not predicted for the area, is my
concern unjustified?

2. Do most towering cumulus clouds not mature into thunderstorms?

3. Wouldn't large towering cumulus clouds have chartacteristics similar to
thunderstorms (severe turbulence, possible hail, heavy rain, icing) even
if they don't end up becoming an official thunderstorm (lightning
present).

Your advice and experiences would be most appreciated.

-Sami, N2057M Piper Turbo Arrow III

I was in one once. A towering Cumulus. A big dark one. Weather said
just rain, no thunderstorms. It started raining. Then I lost some
altitude. Looked up and my airplane was coated with ice! Clear, but
ragged ice, about 1/2" thick on all forward facing surfaces.
Fortunately I had warm VMC under me, so I descended and shed the ice. I
don't fly into dark Cumulus clouds anymore. Only reason I did that time
is I was pretty ignorant of weather. I was just happy to have a
clearance and be able to fly in actual. I was in and out of IMC. Here
comes a big dark one. In I went. Coulda been worse, coulda been hail....

"Doug" wrote in message
oups.com...
I was in one once. A towering Cumulus. A big dark one. Weather said
just rain, no thunderstorms. It started raining. Then I lost some
altitude. Looked up and my airplane was coated with ice! Clear, but
ragged ice, about 1/2" thick on all forward facing surfaces.
Fortunately I had warm VMC under me, so I descended and shed the ice. I
don't fly into dark Cumulus clouds anymore. Only reason I did that time
is I was pretty ignorant of weather.

How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???

I was just happy to have a
clearance and be able to fly in actual. I was in and out of IMC. Here
comes a big dark one. In I went. Coulda been worse, coulda been hail....

"Ron McKinnon" wrote in message
newsG%8e.1066820$Xk.925695@pd7tw3no...

How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???


Why on earth would you criticize someone for admitting that their
weather knowledge was less than they'd like? You can get an IR
without ever flying in a cloud. The knowledge needed for the
written certainly doesn't require that high of a level of understanding.

Real weather is something you learn by flying in it. By gradually
changing your personal minimums as you learn.

"OtisWinslow" wrote in message
...

"Ron McKinnon" wrote in message
newsG%8e.1066820$Xk.925695@pd7tw3no...

How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???

Why on earth would you criticize someone for admitting that their
weather knowledge was less than they'd like? You can get an IR
without ever flying in a cloud. The knowledge needed for the
written certainly doesn't require that high of a level of understanding.

In point of fact it would be a criticism regarding the fact of their
lack of knowledge, not for their admission of it.

But it was in any case not a criticism. It was an expression of a
query; A conundrum. (Some degree of weather knowledge is
in most places a requirement for the Private licence/certificate,
and, considering what's at stake, I'd think a pilot'd would have
acquired more than the bare minimum knowledge by the time
they've got an IR. Apparently not.)

"Ron McKinnon" wrote:
How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???

Most people get very little exposure to making real weather-related
decisions during training. Most of the time in training, you depend on
your instructor to make decisions for you, and just go with the flow.

I don't do any primary training; mostly club checkouts and BFRs and high
performance upgrades, things like that. Presumably these are people who
have already received training in weather. I try really hard to impress on
my students that I want them to make the go-no/go decision, and then defend
it. I'm often amazed at just how ill-equipped many of them are to do that.

I had one guy not long ago, recent instrument rating, working on his
complex transition. We had a lesson scheduled one day where it was IFR,
with freezing levels around 3-4000. He wanted to go flying. He says he
got a FSS briefing and it sounded OK (I can't imagine what the briefer told
him). I had to drag him step by step through DUATS, and show him how to
read the FD reports (he had never seen one before). He had no idea what I
was talking about when I mentioned "airmet zulu", nor how to read one.

By mid-morning, the system had a half-dozen pireps of moderate icing at the
altitudes we would have been at.

I believe the way you learn about weather is by flying in it. By relating
what
you see with what was on the forecasts. Over a period of time that helps
us put the big picture together. Certainly the ideal situation is being
able to fly with a highly experienced CFI when we're getting our rating,
and spend a bunch of time in the clouds. Unfortunately many CFIs are
not that experienced at weather flying.



"Roy Smith" wrote in message
...
"Ron McKinnon" wrote:
How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???

Most people get very little exposure to making real weather-related
decisions during training. Most of the time in training, you depend on
your instructor to make decisions for you, and just go with the flow.

I don't do any primary training; mostly club checkouts and BFRs and high
performance upgrades, things like that. Presumably these are people who
have already received training in weather. I try really hard to impress
on
my students that I want them to make the go-no/go decision, and then
defend
it. I'm often amazed at just how ill-equipped many of them are to do
that.

I had one guy not long ago, recent instrument rating, working on his
complex transition. We had a lesson scheduled one day where it was IFR,
with freezing levels around 3-4000. He wanted to go flying. He says he
got a FSS briefing and it sounded OK (I can't imagine what the briefer
told
him). I had to drag him step by step through DUATS, and show him how to
read the FD reports (he had never seen one before). He had no idea what I
was talking about when I mentioned "airmet zulu", nor how to read one.

By mid-morning, the system had a half-dozen pireps of moderate icing at
the
altitudes we would have been at.

Well, I had received a preflight briefing. No mention of T Storms or
ice. I was below the freezing level. Now you see, if I had KNOWN what
was going to happen to me BEFORE I went into that cloud, I would not
have done it. But I didn't KNOW ahead of time that I would get ice. I
thought it would just be rain and maybe a little bumpy.

Also, I was on my flight plan. My route took me through the cloud.
Flying through clouds is what IFR flying is all about. I didn't see any
lightning. It was a towering cumulus. I'd never had one of those in my
path before. The preflight briefer said it was "just rain".

If I encountered one of those now, assuming I could see it ahead of
time, I'd request a diversion around it. That decision is based on
experience. My experience made me wiser than I was previous to this
event.

It is possible to be ignorant even though one is intellegent, by the
way. Ignorance means one just does not know, is not informed on the
subject on hand. Not that one is stupid or unable to understand the
subject. And the fact that I was ignorant on this subject does not mean
I was ignorant of the entire subject of weather. I was never told not
to fly into towering cumulus clouds. I was told not to fly into
thunderstorms. I believed and still believe there is a difference.

The whole reason I posted was to share my experience with others. Not
to set myself up for ridicule because of my ignorance. I am sorry you
took it that way.

"Doug" wrote in message
oups.com...
Well, I had received a preflight briefing. No mention of T Storms or
ice. I was below the freezing level. Now you see, if I had KNOWN what
was going to happen to me BEFORE I went into that cloud, I would not
have done it. But I didn't KNOW ahead of time that I would get ice. I
thought it would just be rain and maybe a little bumpy.

Also, I was on my flight plan. My route took me through the cloud.
Flying through clouds is what IFR flying is all about. I didn't see any
lightning. It was a towering cumulus. I'd never had one of those in my
path before. The preflight briefer said it was "just rain".

If I encountered one of those now, assuming I could see it ahead of
time, I'd request a diversion around it. That decision is based on
experience. My experience made me wiser than I was previous to this
event.

It is possible to be ignorant even though one is intellegent, by the
way. Ignorance means one just does not know, is not informed on the
subject on hand. Not that one is stupid or unable to understand the
subject. And the fact that I was ignorant on this subject does not mean
I was ignorant of the entire subject of weather. I was never told not
to fly into towering cumulus clouds. I was told not to fly into
thunderstorms. I believed and still believe there is a difference.

The whole reason I posted was to share my experience with others. Not
to set myself up for ridicule because of my ignorance. I am sorry you
took it that way.

I have no idea about the depth or breadth of your weather
knowledge, nor your prowess as a pilot, except from what
you yourself stated, and what you yourself said that you did.

You stated that you were 'Pretty ignorant about weather',
and that you flew into a big, dark, TCU. I can only
infer from this that you were 'Pretty ignorant about weather',
and that you had no idea what to expect within a big, dark,
TCU.

My query was merely one of astonishment, and an expression
of a conundrum that one could indeed be 'pretty ignorant'
about weather' and have no idea what to expect within a big,
dark, TCU by the time they're an instrument rated pilot.

But in this there was no ridicule of you, nor impugning of
your intelligence, nor any intent to do so. I am sorry if
you took it that way. I stand corrected.

"Ron McKinnon" wrote in
newsG%8e.1066820$Xk.925695@pd7tw3no:


"Doug" wrote in message
oups.com...
I was in one once. A towering Cumulus. A big dark one. Weather said
just rain, no thunderstorms. It started raining. Then I lost some
altitude. Looked up and my airplane was coated with ice! Clear, but
ragged ice, about 1/2" thick on all forward facing surfaces.
Fortunately I had warm VMC under me, so I descended and shed the ice.
I don't fly into dark Cumulus clouds anymore. Only reason I did that
time is I was pretty ignorant of weather.

How on earth could you be an Instrument rated Pilot, or even a
non-instrument rated pilot for that matter, and be 'pretty ignorant
of weather' ???

I was just happy to have a
clearance and be able to fly in actual. I was in and out of IMC. Here
comes a big dark one. In I went. Coulda been worse, coulda been
hail....


I suspect that his level of "ignorance of weather" was that he was unable
to accurately predict the conditions inside that dark towering Cumulus
cloud he flew through.

I also suspect that most pilots, VFR or IFR, have been in the same boat at
some point after their IFR training, especially since it is not a pre-
requisite to receiving the instrument rating. We are mostly taught to
depend on forecasts and spend very little time during training on learning
to properly identify cloud formations from actual pictures or live
representations, and to understand what to expect within each type of
cloud.

During VFR training, you learn to just stay away from them. And during IFR
training, you get pounded about the extremes (CBs and Stratus clouds) but
there is really inadequate training of the stuff in the middle - probably
because the stuff in the middle varies so widely.

Can you accurately predict conditions inside of a towering CU unless you
get inside of it? There are different conditions even within the same cloud
that depend on many factors that include pressure, elapsed time, wind
speed, humidity levels, etc. So while one dark TCU may produce hail, rain,
and ice, the next dark TCU might be fairly uneventful and produce some
turbulence as you enter and exit and that's all.

I think most people are fairly ignorant of weather, even if we think we are
experts. Otherwise the meteorologists would never be wrong, and the rest of
us COULD just depend on the forecasts...