Set the temperature, dew point and stability of the air and watch the sky build itself: fog, flat layers or towering cumulus. Then fly your drone through it and see the Part 107 cloud clearance box in 3D.
Each card ties one test idea to something you can change above.
Dew point is the temperature the air must cool to before it is saturated. The gap between temperature and dew point is the spread.
A small spread means moist air: low clouds, mist or fog are likely. A big spread means dry air and high cloud bases.
Drag dew point up toward the temperature and watch the cloud base drop.
Divide the spread in °C by 2.5 and multiply by 1,000 to get the base in feet above the ground. A 10 °C spread gives about 4,000 ft AGL.
In °F, divide the spread by 4.4 instead.
Set 24 °C and 14 °C, then check the base chip at the top of the 3D view.
Slide stability from one end to the other and watch the cloud type change.
Fog is a cloud that starts within 50 ft of the ground. Radiation fog forms on clear, calm nights when the ground cools the air to its dew point. Advection fog forms when warm, moist air moves over a cold surface.
Pick the "Morning radiation fog" scenario.
The ceiling is the lowest layer reported as broken (BKN) or overcast (OVC), or the vertical visibility (VV) into fog. Few and scattered layers are not a ceiling.
Set coverage from SCT to BKN and see the ceiling appear in the readout.
Warm, moist, unstable air builds cumulonimbus: towering clouds with heavy rain, hail, lightning and violent up and downdrafts. Their tops can reach 40,000 ft and beyond.
Pick "Thunderstorm building", then move your drone near it.
Practice questions written for this app.