We’ve posted over 40 Go Or No Go scenarios at Air Facts, where we present a weather briefing and ask if you would make the proposed flight. All of these are based on real weather conditions, but most are not real flights we took. The point is to practice making decisions and share your thinking with other pilots.
This one is different: I was trying to fly home to Cincinnati, Ohio (LUK), from Pittsburgh, Pennsylvania (PIT), at the end of 2019, and the weather wasn’t great. The screenshots below are the actual ones I was looking at as I sat in the lobby at Atlantic Aviation in Pittsburgh, making my go/no-go decision. I’ll share the weather briefing, then ask you to add your comment about what you would do. Then, at the end, I’ll reveal what my decision was and what my thought process was.
I encourage you to think about this scenario based on the type of flying you do and the type of airplane you fly. In my case, I was flying a Pilatus PC-12, so I had good equipment: glass cockpit, datalink weather, on-board radar, and deice boots. I have about 1,000 hours in the airplane and am IFR proficient.
The goal on this day was to fly my family home after a brief visit to Pittsburgh, so while safety is always the number one priority (my standards do not change depending on the passenger), comfort was also an important consideration. Flying is supposed to be both convenient and fun for my wife and two kids. A modest headwind meant the flight was forecast to take 1 hour and 7 minutes at typical cruising altitudes (usually between 18,000 and 22,000 feet for a shorter flight). Proposed departure time was 2030Z.
The route overview in ForeFlight wasn’t too pretty, and neither was the view out the window. Rain was covering the map and there were plenty of PIREPs for icing and turbulence.
The driving force behind this messy weather was a low pressure system moving into the Great Lakes, with an attached cold front stretching all the way from Minnesota to Texas.
The prog charts showed this system marching across Indiana and Ohio, with the front slowly occluding.
Overnight, the low was forecast to strengthen and even produce areas of convective activity.
How about tomorrow? The prog charts showed the system finally moving through PIT Monday morning, but with leftover rain and winds behind the front.
Satellite and SIGMETs
The radar image above showed some yellow cells, but mostly green with a shallow gradient. There were no sharply-defined lines and no cloud-to-ground lightning symbols on the map. To me, this looked like almost all rain, with very little convection. Further west, closer to the cold front, there appeared to be some nastier stuff, but the rain over Ohio and Pennsylvania looked like classic warm front weather.
To get another look at it, I reviewed the satellite imagery. First, the infrared satellite, overlaid on my route.
Then I looked at the visible image, which didn’t show a whole lot of detail:
Another tool for determining whether rain is convective or not is the Convective SIGMET. This showed the potential for some storms to the southwest of my destination, but nothing over Ohio.
At this point I was fairly certain that this weather system didn’t contain any big thunderstorms; maybe some moderate rain, but not too much more than that. The bigger concern was in-flight icing—my route would be east of a low and along a warm front, often the area of worst icing in a large weather system. A good place to start is with the Graphical AIRMET, and sure enough, this showed lots of ice:
That’s a good overview, but it’s pretty rough. For a more detailed look, I went to the ForeFlight Maps page and the Icing forecast layer. I reviewed this at a number of different altitudes. While 20,000 feet would be typical on a flight like this, I suspected lower might be better. For one, it looked like I wouldn’t be getting on top today—even at FL220 the icing was mostly light but it was still ever-present:
At FL200 things got worse:
It was the same story at 18,000 and 16,000 feet, with solid blue all along my route (indicating moderate ice).
By 12,000 things seemed to be lightening up just a bit:
And by 10,000 it looked like we would be out of any ice:
But these maps, while really powerful, only show the severity of icing. I was also interested in the probability of icing—how likely was it that I would get that moderate ice? For that, I went to the Imagery tab in ForeFlight. These charts showed a pretty high likelihood of ice from the mid-20s on down. Here’s FL190:
At 15,000 feet, the probability was even higher:
By 11,000 feet the chance of icing was a lot lower over central Ohio, although more ice was forecast to the west of my destination:
So far it looked like a pretty high chance of moderate ice between about 12,000 and 22,000 feet. Time to back up those forecasts with some real world observations: PIREPs. There were a lot of these, but most mentioned light icing, not moderate or worse. The static chart in the Imagery tab gave me a good overview:
Next it was time to look at specific PIREPs to see how old they were, what altitudes they mentioned, and what the airplane type was. First up was a report just north of Columbus, Ohio, with light mixed icing between 17,00 and 19,000:
South of our course, a Cessna 421 reported light rime at 12,000 feet.
Just west of there, a Piper reported moderate rain and light chop at 10,000 feet, but no ice. Those negative ice PIREPs are really valuable, and far too rare—this helped me set a floor for the icing threat.
A 737 reported light icing at 23,500, suggesting that there was no topping this weather (at least in a Pilatus).
West of Dayton, Ohio, a regional jet reported light rime at 20,000 feet.
That lengthy review of the icing conditions suggested that I would very likely pick up some of the white stuff, but the PIREPs looked a lot less worrying than the forecast charts. Next on my list was turbulence—as I mentioned, I’m flying my family, not freight, so a good ride is always appreciated. With all that frontal activity, was this going to be a rough day to fly? The Graphical AIRMET wasn’t too encouraging, with lots of bright colors and warning about low level wind shear (LLWS).
But once again, I find this chart to be just a starting point. It doesn’t have the detail to really help me make a decision. For that, I turned on the turbulence forecast layer on the Maps page in ForeFlight. At 18,000 feet, the map was pretty encouraging—all the ugly stuff was well west of my route.
The story was the same at 16,000 feet:
And likewise at 12,000 feet, with nothing more than light:
So far I had spent a lot of time on en route weather, but the ceiling and visibility weren’t great either. At PIT, conditions were IFR with rain and mist, and forecast to stay that way.
At Lunken, conditions were actually quite good, with a very high ceiling and light rain. Overnight things were forecast to get windy and rainy, but not until well after my ETA:
Now I’d like to hear what you think. Given that weather report, would you have made this flight or canceled? Write down what you think—before you read my decision below!
What I Decided
In the end, I decided to fly. It wasn’t automatic—there was a lot of weather to consider here in any airplane—but by the time I walked through the FBO doors, I was pretty confident that we would have not just a safe flight but a pretty smooth one too. Here was my thinking:
- I always start with the big picture, and while that showed a winter warm front and an approaching low, my route would be east of the main frontal zone. It looked to me like the cold front and occlusion were the worst weather, and I was going to miss both of those.
- After the big picture, I always evaluate the three major weather threats: thunderstorms, icing, and low IFR conditions. These are responsible for the vast majority of weather accidents.
- Storms: I was confident that we would fly through nothing worse than moderate rain. That can be unnerving, but it’s perfectly safe. The radar image had no unusual shapes, no bright orange or red, and no lightning. This was warm front rain, not a squall line.
- Icing: this was probably my biggest concern. While the PC-12 is approved for flight into known icing conditions (and handles it quite well), nobody likes slogging through moderate ice. While the forecast products looked less than ideal, all the PIREPs were for light ice. Plus, I knew that I would be out of the ice by 10,000 feet (and in VFR conditions closer to home). That’s low for a Pilatus, but it gave me a solid out if things really got ugly.
- Low IFR: I fly a lot of IFR and had a co-pilot in the right seat, so the PIT weather wasn’t much of a concern for me. It was well above approach minimums if I had to get back, and the weather at LUK was excellent.
- After threats comes comfort: even if the flight was perfectly safe, would my passengers get beat up? On this topic, things looked surprisingly good. Both the PIREPs and the turbulence forecasts showed pretty good rides below 20,000 feet. While I don’t have screenshots of it here, the winds aloft also weren’t blowing too hard or showing much sign of shear (at least over Ohio—west of that cold front things were much more exciting).
How it went
We took off into light rain and quickly went IMC. We wouldn’t see the ground again until we descended into Cincinnati. But we had a smooth ride, with just occasional light turbulence (and not even much of that). There were some pockets of moderate rain, but nothing convective. Here’s the SiriusXM radar image on Garmin Pilot:
We started out at 16,000 feet, but about 20 minutes into the flight, we started to pick up some ice. I would call it light with a few spots of moderate. The boots were keeping up but I don’t like hanging out in ice so we went down to 14,000 feet. At that altitude we were almost completely ice-free, and by the time we were 20 miles northeast of Columbus the clouds were starting to become more layered. We made an uneventful landing in Cincinnati and had the airplane in the hangar long before the heavy rain moved in.
Some might say the weather was only going to be better tomorrow, so why not wait? That ended up being true, but only in terms of rain and ceiling. The cold front ended up being a strong one, with thunderstorms overnight, and the winds created some truly bad rides. A Monday flight would have been doable but unpleasant.
Sometimes as pilots we rationalize any decision that doesn’t kill us (“I made it, so I must have made the right decision”), but I’m happy with both my decision and my process for making it. This was worse than normal weather for me, but not dramatically so.
As always, we welcome your comments below.