Cutting the pie
Going back to Private Pilot 101, we hopefully know that a “ceiling” is defined as the height above the earth’s surface of the lowest layer of clouds or obscuring phenomena that is reported as “broken,” “overcast,” or “obscuration,” and not classified as “thin” or “partial.” Said another way, only broken or overcast layers are considered a “ceiling.” And referring back to our flight category chart above, we see that the categories (colors) are based on ceilings and visibilities.
Cloud layer coverages are measured in oktas or eights. A FEW (few clouds) layer is 0 to 2 oktas in coverage, an SCT (scattered) layer is 3 to 4 oktas, a BKN (broken) layer is 5 to 7 oktas and an OVC (overcast) layer is 8 oktas. Remember, only BKN or OVC is deemed a ceiling. Because FEW and SCT aren’t considered a “ceiling” as outlined in the chart above, their presence isn’t taken into consideration in terms of the Flight Category Color Coding. This is where devilish details lurk. You could easily have a SCT layer (up to 3-4 eights) and still have the green-dot flight category showing on your favorite weather site or app. That SCT layer could be insanely low, like 300 AGL, and the flight category dot would still show green. Multiply this situation at all of your closest reporting stations, and it is easy to see how we can fall into the “Green-Dot Syndrome.” Pilots launch predicated on the screen full of green dots, and don’t see the FEW and SCT details that may be awaiting them. Not to mention, a SCT layer has to increase by only one additional okta to have a “legal” ceiling on your hands.
Potential cure coming
The remedy for this facetiously described “syndrome” is just on the horizon. In fact, it is already available on the National Weather Service beta (experimental) platform at
https://beta.aviationweather.gov. Hopefully it will be available on the “legacy”
aviationweather.gov platform by January 2023. The “cure” comes in the way of a new addition that includes an orange(ish) circle around any Green Flight Dot Category that includes a FEW or SCT layer of less than 3000 AGL.
This addition is priceless; hats off to the NWS for considering end users’ feedback and creating it. While the NWS has taken the lead on this initiative, we can only hope the popular electronic flight bag (EFB) apps will follow suit.
So now, those devilish details will jump out. Hopefully this causes pilots to take a closer look and avoid Green-Dot Syndrome.
Matt has been an FAA Designated Pilot Examiner for over a decade, conducting exams ranging from Private to ATP and CFI. Additionally, he is Single-Pilot IFR Air Medical Captain and Part 135 Instructor and Check Airman. He can be reached at
HelicopterDPE@gmail.com and via Twitter @ HelicopterDPE
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