Determining which clouds to fly into IFR

K

ksarrowpilot

Filing Flight Plan
Joined
Jun 24, 2013
Messages
10
Location
Kansas City
Display Name
Display name:
ksarrowpilot
I'm working on my IFR rating and have a question. How does one determine which clouds are OK to fly into? The weather yesterday in KC had many layers of clouds from 2500 agl up to FL400. See the attached photo. No clouds were showing up on radar as no moisture and no lightning was present. So if you're on a long cross country in a small single engine plane with a 10k altitude limit, and you run into a giant band of these huge clouds that stretches for miles, are you OK to go through them? How do you determine how dangerous a cloud is? I asked our company ATP and after a long pause he said "I can't answer that - you have to use your own judgment". He says you judge intensity by how hi the tops are, and how much moisture they are producing, lighting, etc but what other sources of information do you have for big white clouds that will likely soon get nasty? Do you just eye-ball the situation and make a judgment call to continue, re-route or land? Any advice would be great. Thanks Cloud.jpg
 
Go review the weather material. In fact download the FAA's book on weather. First indication is the type of clouds and the height of the tops. Remember what & how Tstorms develop and stay far away.

It also depends on the time of the year. Summer is notorious for Tstorms, and most cloud formations indicate storms.

It's never the wrong decision to land and wait out the weather even with the IFR.
 
If you have to think about it, stay out of it. Study the books (including Aviation Weather) and eventually, you'll learn though that and experience which ones you can safely (but perhaps uncomfortably) penetrate.

BTW, if you have ForeFlight, you can download Aviation Weather in the Documents section, and have it in a nice, portable form you can carry with you and read almost anywhere.
 
murphey said:
Go review the weather material. In fact download the FAA's book on weather. First indication is the type of clouds and the height of the tops. Remember what & how Tstorms develop and stay far away.

It also depends on the time of the year. Summer is notorious for Tstorms, and most cloud formations indicate storms.

It's never the wrong decision to land and wait out the weather even with the IFR.
Click to expand...

It's not that easy IMO. The books give you the basics but not the judgement. Is that specific clound formation up ahead safe, safe but annoying to pax or to me, safe but scary, or actually dangerous? Is that cumulus building strongly or slowly? When does a cumulus cloud begin to discharge? How bad will turb be in that one? The books help for sure, but they aren't a substitute for experience. I didn't get any IMC during training so I really needed to get my ticket 'wet' before flying in IMC with my family.

The answer for me was to go rain hunting with my instructor after my checkride. In Denver that often means a long flight in the AM in order to find something that won't kill you. Do it in the PM and risk death. :)

We went and found some green precip with a little yellow in it and shot an ILS to McCook, NE to about 600 AGL. It was light rain with some moderate and it wasn't convective at that time of day - more of a leftover from the night before.





I learned a lot from that and later experiences:
  • Light to mod rain from a stable or lightly lifted airmass can be OK.
  • Clouds are way more disorienting than foggles. They just are. Not a big deal if you are ready for it.
  • I began a slight turn upon entering IMC the first time. My instructor told me I would and I didn't think I would... but I did. Easily corrected.
  • Transitioning from IMC to VMC is a little harder than just lifting your foggles
  • How to know the difference between a benign, annoying, scary and dangerous cumulus cloud? I learned how to judge them from the air when you can't see what's falling from under them. Strongly building cumulus is very puffy with crisp edges. Lightly building cumulus is less so. Dying cumulus has soft or hazy edges and often has rain or virga (but you may not be able to see that airborne).
  • My airplane hums in clouds (at cruise anyway). Not precip static but it sounds like rushing wind. I guess it's the sound of microscopic 'drops' of moisture rushing over the skin. That one was unexpected.
Anyway, I agree with the OP that the IR can leave you with a lot of questions if you don't get much 'actual' during training. Best to get with an instructor during or after training and get your ticket wet.
 
Last edited:
The ones that don't look scary. If they look like bunny rabbits or teddy bears, I usually go through those. If they are dark and scary I shy away from them.
 
What kind of radar? Are you just talking NEXRAD? That can be a little iffy for tactical decisions.

I'd keep a eye on any clouds with extensive vertical development, also if you have an ADF you can use it as a lightning detector.

When the few points are above 18C that's also a sign to keep a eye out.
 
ksarrowpilot said:
I'm working on my IFR rating and have a question. How does one determine which clouds are OK to fly into? The weather yesterday in KC had many layers of clouds from 2500 agl up to FL400. See the attached photo. No clouds were showing up on radar as no moisture and no lightning was present. So if you're on a long cross country in a small single engine plane with a 10k altitude limit, and you run into a giant band of these huge clouds that stretches for miles, are you OK to go through them? How do you determine how dangerous a cloud is? I asked our company ATP and after a long pause he said "I can't answer that - you have to use your own judgment". He says you judge intensity by how hi the tops are, and how much moisture they are producing, lighting, etc but what other sources of information do you have for big white clouds that will likely soon get nasty? Do you just eye-ball the situation and make a judgment call to continue, re-route or land? Any advice would be great. Thanks View attachment 35209
Click to expand...


I don't go through that, I go under.
 
Thunderstorms, which are cumulus clouds with lightning and/or thunder are a definite no go. Towering cumulus, although not as bad, should be avoided under most circumstances. They look like thunderstorms but don't have thunder or lightning. Clouds that are below 35 degrees F are out due to ice. Night IMC is dangerous due the seriousness of an electrical failure.

Look at the weather on the computer, look at the pilot reports, talk to ATC when you get your briefing and decide.

It's always safer to have VFR under you ABOVE the MVA. That way, if things go wrong you can descend and get to VFR.
It is also safer to have VFR within fuel range somewhere as an escape route. It's also safer and easier if you just fly out of the IMC at altitude and into VFR and land VFR. That way you don't have to worry about flying an approach.
I'd suggest you try and get these kinds of "friendly" IMC to fly in for your first IFR flights into IMC. And perhaps file IFR, on your own, in VFR just to get practice doing that on your own.

Good luck! It can be a lot of fun to fly in the clouds!
 
Last edited:
I avoid any cloud deck with vertical shafts that's extending into the flight levels. You'll get strong drafts inside those vertical shafts. Any red or higher color on the radar is to be avoided. If it's dark green to slightly yellow, over a wide area; it's possibly stable and can be flown threw if you have experience.

I'll look at the radar, cloud tops and the satellite view and determine what's the best course.

Avoid any clouds that look like smooth convex lenses, especially over mountain ranges. Those are lenticular clouds and extremely dangerous.

http://www.crystalinks.com/lenticularlogo.jpg
 
If the clouds are classified as CB, ACSL or if the temp is less then 4 degrees Celsius, then stay out of those clouds.
 
Last edited:
There is no good answer and the above is good advice. You'll learn over time what you can do. You'll also learn when you need to tighten up your seat belt...
 
It's your choice,it will take time for you to determine what you are comfortable with. If you have flight following or on an IFR flight plan,you will get a lot of help from the controllers.
 
ARFlyer said:
I avoid any cloud deck with vertical shafts that's extending into the flight levels. You'll get strong drafts inside those vertical shafts. Any red or higher color on the radar is to be avoided. If it's dark green to slightly yellow, over a wide area; it's possibly stable and can be flown threw if you have experience.



I'll look at the radar, cloud tops and the satellite view and determine what's the best course.



Avoid any clouds that look like smooth convex lenses, especially over mountain ranges. Those are lenticular clouds and extremely dangerous.



http://www.crystalinks.com/lenticularlogo.jpg
Click to expand...



I read somewhere (forgot exactly where) that the lenticular clouds really aren't that turbulent since the air is flowing smoothly over the terrain. Rotor clouds are what you have to watch out for.

Seems to make sense, but so far, I have avoided both types, so I can't say for sure.... ;)
 
Igneous clouds? Is that like cumulogranite?
 
dans2992 said:
I read somewhere (forgot exactly where) that the lenticular clouds really aren't that turbulent since the air is flowing smoothly over the terrain. Rotor clouds are what you have to watch out for.

Seems to make sense, but so far, I have avoided both types, so I can't say for sure.... ;)
Click to expand...

If you've been in mountain wave then you've been in the same airflow as a lenny. As you note they are smooth.

The rotors are to be avoided. If the rotors are at reasonable altitude above ground level then you may be able to pick your way through them. Do not attempt to pick your way through rotors that go to ground level. You will find the "avoid at all costs" rotors down wind from big mountains in an area of high ground elevation. My favorite example is downwind of Elk Mountain which is west of Laramie, WY. You can sit in the rest stop along I-80 and watch all the weather when things are whipped up - you can learn a lot with an hour of observation on the right day.
 
Go to www.aviation.gov and look for convective SIGMETs under Forecasts, SIGMETs.

Bob Gardner
 
petrolero said:
I learned a lot from that and later experiences:
  • Clouds are way more disorienting than foggles. They just are. Not a big deal if you are ready for it.
  • My airplane hums in clouds (at cruise anyway). Not precip static but it sounds like rushing wind. I guess it's the sound of microscopic 'drops' of moisture rushing over the skin. That one was unexpected.
Click to expand...


I found exactly the opposite with the cloud vs foggles thing. I'd much rather be in actual. Far nicer to be able to glance over at engine gauges, etc. Flying directly into sun with foggles on will make you cry. Ha.

Most Cessnas whistle. Not kidding. Sounds like someone blowing gently over a bottle but fairly high pitched.
 
I'm VFR only so I'm in the wrong viper pit to give advice, but I'll only bust a cloud for fun when I can see all the way around it. And it can't be building. Just puffy clouds.

Otherwise, it's go under and scudrun time or land for me.

Or turn around. A good pilot should turn 180 degrees if he needs to, and not hesitate or agonize about it for a second. We fly airplanes. We'll get there quicker than anybody when we can, so it can wait. Besides, being forced down is part of meeting new people and the adventure of flying. You probably need to pee and need fuel anyway ... :)
 
...I'll push through the puffy clouds on a climb or descent...but only the ones I know I'll be in for a few seconds and it's easier to just push through than going around.

I flew in some good rain once in my ppl training. We went up to do pattern work and it started raining pretty good. I was suprised at how good the prop is at clearing the rain...was better than windshield wipers. :) It wasn't near as bad as I imagined it being.
 
Assume ground is at sealevel, the ideal cloud layer for easy IFR would be bottom of clouds at 4000', with tops 8000'. Just nice above 40 degrees at the tops and not cumulus, no turbulence, rain is ok, stratus type clouds. This allows you to be vectored below the clouds and you have the climb to fly above them and you will be in the clouds both coming and going.

Now as for approaches, start with 1000' with 2000' tops. That way you're in VFR both at the IAF and well above minimums.

Misc puffy cumulus clouds are fun, get a block altitude and just fly around them, under them, through them etc.

Yeah and try finding THAT all the time.
 
flyingron said:
Igneous clouds? Is that like cumulogranite?
Click to expand...

Not much cumulogranite around here...there is some cumulobasalt but it's mostly metamorphic rock so it's the schist to bump into...

(geology joke - cumuloschist also works)
 
Clark1961 said:
Not much cumulogranite around here...there is some cumulobasalt but it's mostly metamorphic rock so it's the schist to bump into...

(geology joke - cumuloschist also works)
Click to expand...

Uggggg....:rolleyes2::rofl:;) What has the world come to when I laugh at geology puns...:dunno:
 
Henning said:
Uggggg....:rolleyes2::rofl:;) What has the world come to when I laugh at geology puns...:dunno:
Click to expand...
Well....northern Italy is gneiss this time of year...no, it's marbleless!
 
You must log in or register to reply here.
Back
Top