Keeping weather flying rules in mind

Basic atmospheric knowledge that's essential for pro pilot flying.

By Karsten Shein
Comm-Inst, Climate Scientist

Cleveland Peak Pilot Kirk Garner checks weather at Texas Jet FTW (Meacham, Fort Worth TX). While reading weather maps is a critical skill for pilots, being able to visualize what the maps are indicating is just as important.

or the past dozen or so years, this article has been about advancing the pilot's understanding of the atmosphere—all aspects of weather and climate—geared toward professional pilots who already have a general knowledge of meteorology.

Unfortunately, there is no clear, prescribed training in meteorology mandated by the authorities. Instead, pilots have in­evitably gained this core knowledge piecemeal from various sources—formal atmospheric science classes, ground school, flight instructors, weather briefers, even fellow pilots.

This also means our weather backgrounds vary widely—so it's important to reflect occasionally on what weather knowledge base should be shared by all pilots as essential.


What does a pilot really need to know about meteorology? Because weather is such a major factor in flying, we often feel as though we have to be meteorological experts, able not only to fully understand the complexities of dozens of weather charts but also to interpret correctly all pertinent weather information fed us by briefers and automated services.

But is this too much to expect from a pilot? Just how much meteorology does a pilot need to know? The following excerpt provides an interesting take on this question.
"Some knowledge of the air and its ways obviously is essential to both the science and the art of aerial navigation.

It does not follow, however, that all who are concerned with this science and this art need to know exactly the same things about the atmosphere, nor to know them in exactly the same way. The designer of the engine must know the composition and density of the atmosphere at all levels at which the machine is supposed to operate, since these are essential factors in the determination of the power available, but he does not need to know much about the theory of turbulence, skin friction, stream lines and the like.

These vitally important matters concern, most of all, the designers of the wings and the fuselage. Finally the aviator, though his very life depends on somebody's knowledge of these things, does not often himself bother about them. He would be bored beyond endurance by the exact observations, experiments, 'high-brow' theories, and tedious calculations they require. His is the active, impatient spirit that wants to be up and flying.

He would rather fly a 'barn door' right away than hang around a month or two waiting for the finest product the laboratories can produce. Neither does he care to know, nor much need to know, the technical terms and long equations which the meteorologist uses in his discussions of wind and weather. He takes his machine, engine, wings and all, as prepared by others, and he wants the prediction of the weather the same way—handed to him on a platter, as it were.

And in the main his wishes are entirely reasonable. Never­theless, while in the air and on making a forced landing, the aviator has to be very much 'on his own,' as we say. At such times a working knowledge of the machine and a practical understanding of the atmosphere are essential."

These words were penned by US Weather Bureau Meteorological Physicist William Humphreys as part of an article entitled "Meteorology and its importance to aviation" which appeared in the Monthly Weather Review in 1930.

Humphries continued, "But to be specific, exactly what knowledge of meteorology does the aviator really need, when there is a specialist at every airport to tell him what the weather is along the route he is about to take, and what it is expected to be at every mile of the way?

Chart of forecast turbulence intensity between 10,000 ft and FL450 over North America. While areas of moderate or stronger turbulence are easy to identify, an understanding of the atmosphere will aid in determining likely altitudes at which that turbulence could be expected.

Well, he needs at least enough knowledge of meteorology to enable him to read a weather map understandingly; enough to enable him to discuss this map intelligibly with the man who makes the forecasts for him; enough to enable him to judge, while in the air, whether or not the forecasts are coming true; and enough to give him an understanding of the weather significance of the clouds and the look of the sky.

From his study ... he learns what sort of weather to expect at each particular place and time. But weather does not always come exactly according to the forecast. It therefore is essential that the aviator know not only what kind of weather he probably will encounter, and where, but also he must definitely understand the significance of the clouds and other weather appearances and their relations to the anticipated weather...

In short, in addition to being able to consult intelligently with the station meteorologist and read knowingly the weather map, he must be able to visualize that map in terms of actual weather phenomena, and especially must he become weatherwise for the route he is flying, just as the fisherman is weatherwise in respect to his own home waters."

Humphreys continued to expand on "a number of (additional) facts about the atmosphere the aviator should know." Knowledge of these basic facts is as important to pilots today as it was 80 years ago—perhaps even more so since, in this age of information overload, it is all too easy to overlook the bigger picture while getting caught up in the details.

And a focus on details often obscures a pilot's understanding of the way the atmosphere works, and thus how the conditions he or she sees translate into personalized short-term forecasts that can avert bad weather decisions.

Knowing the atmosphere

So what is the essential weather information every pilot should know? Humphreys is correct in that a pilot must know how to read a weather map so that it may be discussed intelligently with the briefer.

At the very least, we must all be able to look at a weather map and visualize the weather conditions associated with each symbol. To do this, we must understand enough about the atmosphere to not only be able to visualize the weather associated with the map's symbols, but also be able to determine if the weather through which we are flying is shaping up as forecast.

Pilots make preflight decisions based on the current conditions and the forecast, but a lot of accidents could have been avoided over the past 100 years if only the pilot had recognized rapidly changing conditions or a blown forecast early enough to do something about it.


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