Precipitation intensity

W

wind_shear

Pre-Flight
Joined
Jan 7, 2021
Messages
30
Display Name
Display name:
7500
What intensity of precipitation will you guys fly through as an instrument rated pilot on an IFR flight plan? light to moderate? or greater? I don’t mind some green and small areas of yellow. I’ll stay away from heavy to extreme as that’s more often than not associated with thunderstorms. I have no problem asking for deviations but I’ve also been trying to get more experience and build my confidence by pushing myself within my comfort level with the weather while flying IFR. I’m hard on myself and always want to exercise the best airmanship that I can. Obviously a lot of it comes down to experience and the equipment that you are flying and the wx that day. I’ve seen some people punch right through moderate to heavy and not even think twice it seems and others will ask for deviations. what do you guys typically do? Thanks
 
Green only, if I can confirm it’s not worse visually. Not at night, no night IFR. Hobby pilot.

Question: how are we sure that the depiction showing green is not worse (question of tool accuracy or spatial variability) or hasn’t gotten worse or won’t get worse (question of temporal variation). That’s why my answer is green - it includes a safety margin for my own personal risk tolerance. YMMV.

I was a passenger going through an area of purple and white before I knew any better. I believe we survived because we were actually behind it, since there was a delay in the data. ATC even warned us about the area of heavy precipitation. I’ve flown with that pilot since, but only in my plane when I’m PIC.
 
Last edited:
Depends on the temperature in colder months or possibility of convection. In the warmer months around here rain is mostly associated with convective activity. With no onboard radar I keep my distance if there is any convection forecast or appears on ADS-B radar. Light to moderate rain with all stratiform clouds and NO chance for convection is a go if temperatures are well above freezing. I fly a 182 with no anti-ice capability.
 
Green, dark green are ok, will mostly go around yellow. Never into red. Foreflight used to exaggerate precipitation, getting a little better now. (This is versus the Garmin display in the AC). Heavier precipitation will erode paint on the prop and body of a Cirrus. Also wrecks decals.
You have to be careful on convective days. It can go from clear to airplane destroying down pour and drafts quickly. I stay in VMC and if there is a dark threatening area ahead, I go around it. Saved my bacon more than once.
 
All of the responses saying “green” or “yellow” - is there really a standard calibration between radar return (Db) and display color across all platforms? Does yellow in Foreflight mean the same intensity as Garmin Pilot or MyRadar?
 
In typical stratiform precip, or lake effect cloud (<9,000 MSL tops) precip, green on XM weather or ADSB is pretty benign. I avoid large patches of yellow or worse. Scattered stuff you can just avoid. Solid precip has to be pretty benign for me to barge in with a light single. That means any widespread precip with significant convection or icing is no-go. I prefer to have high ceilings flying below or be on top with blue sky above. Seeing weather is better when possible. But I have done some trips where I was in continuous lazy stationary front precip from takeoff to landing. It's kind of amazing, but noisy! (And you will find any canopy leaks.) On top is much better.
 
It depends on the nature of the precipitation.

If it is from convective activity, and/or with strong contouring, I'll want to stay out of all of it.

If it is widespread rain in stable air then it's not usually an issue. I've flown through large areas of red returns with moderate to heavy rain and a smooth ride.
 
Green is no problem, I’d want warmer temps to avoid icing. Sometimes on long trips when it is hot or the airplane is dirty, I’d prefer flying through the rain. It really cools things down. I use foreflight and measure the distances so I know what I’m getting myself into, and I believe I have only done this VFR, both day and night. I like my visibility.

But yes rain does ruin the paint and makes my airplane pretty dirty, the exhaust or something from the engine gets all over the side of the airplane. But it’s easy to wipe off.

I would try yellow in the future, the visibility really starts to decrease due to the water droplets on the windscreen obstructing your view, so I wouldn’t want to do it for long. Maybe 5 minutes in yellow, 30 min in green or so. Also I’d check clouds in flight to see what I’m working with ahead. And I don’t want to go there if I see the lightning bolt in foreflight.
 
Years ago, I was flying in rain and Grand Rapids Approach asked me "What are your flight conditions?"

"Moderate rain, negative turbulence," I replied. I no longer remember how it was displayed on the moving map.

"I show you in the middle of some level five precip," the controller told me.

Well, it was pretty much a non-event. Your mileage may vary.
 
Be careful applying colors and rules across the whole country. Summertime in FL, not getting near any color as it's going to be convective. Other parts of the country it can be fairly benign, depending on what's driving it as others have pointed out. In West Texas, I'm going to give anything a pretty wide berth given the gust front can be miles in front of any precip.

You really need to know more than just color to decide what to fool around in and near.
 
Totally agree on the convection comments. I do green and yellow only with non convective stuff and Im normally IFR. And yes it ruins the paint. You should see my wing tips. Sigh.
 
Generally, if the StrikeFinder's clear, I'll fly through it. Having said, I haven't flown through red since ADSB-in became available. Before that, ignorance is bliss.
 
For me, it also depends on the shape and definition of the return.
 
If you can afford to repair and repaint, by all means fly through it…. It’s only rain right?

799bf9135475aa10364776a05455461c.jpg



Sent from my iPhone using Tapatalk
 
I have wondered if these returns have any sort of vertical component or are they showing a cumulative return from the bottom of the radar coverage to the top.

i have flown in clear air over red areas on NEXRAD...more than once...

Anyone have informed insight into this?
 
It all depends on if it is set up as a composite radar.

I have flown in areas that show red cells all over on the G3 X and the weather out my windshield is perfectly clear
 
I see that no one has mentioned radar attenuation. How do folks deal with only one color on the display to choose from? Not an entire rainbow. I was chatting with a NWS meteorologist once and asked him if attenuation was an issue with their equipment. He said "Yes." However, multiple radars looking at precip from different angles make it a non issue.
As for rain ruining a paint job, I recall reading some info that came with a new Barron. "Avoid flying through rain for a specified (I forget how long) period until the paint sets up." I friend had just restored a Bonanza and finished with an outstanding maroon, red and black paint job. After only a few months after painting, ATC ran him through a cell and stripped a lot of it off. He was actually taking steps to sue the controller.
I once spent 30 to 40 minutes in sleet and it sand blasted all the paint from all the leading edges of everything on a UH-1. It was a medevac mission and I couldn't help it.
 
AlleyCat67 said:
All of the responses saying “green” or “yellow” - is there really a standard calibration between radar return (Db) and display color across all platforms? Does yellow in Foreflight mean the same intensity as Garmin Pilot or MyRadar?
Click to expand...
No
Some have light green then dark green, while another platform shows the dark green as yellow.
 
Gilbert Buettner said:
Years ago, I was flying in rain and Grand Rapids Approach asked me "What are your flight conditions?"

"Moderate rain, negative turbulence," I replied. I no longer remember how it was displayed on the moving map.

"I show you in the middle of some level five precip," the controller told me.

Well, it was pretty much a non-event. Your mileage may vary.
Click to expand...
Leaving Oshkosh in 2000, over Wisconsin I got hand off. The new controller said that I should be out of the level 3 echoes in about15 minutes. WTF?!, what level 3 echoes.

It was raining, but not that heavily.
 
k9medic said:
If you can afford to repair and repaint, by all means fly through it…. It’s only rain right?

799bf9135475aa10364776a05455461c.jpg



Sent from my iPhone using Tapatalk
Click to expand...
My very experienced aviator friend taught me the same. Said "sure you can fly through light rain but how much do you like your paint job"?
Being that I only fly a 172 mostly for fun I fly around rain. Every once in a while I have flown in light rain but why? So I don't. My paint get's enough wear just wiping bugs off especially if you fly everyday during the summer months like I do.
 
I find it useful to overlay radar with satellite IR. Precipitation intensity with how cold the tops are give a good picture of what is going to happen as much what is happening now. I don't know if this can be done inflight, but aviationweather.gov has this.
 
You must log in or register to reply here.
Back
Top