Overcast versus Obscured - Clouds Protocol

Overcast versus Obscured: What’s the difference?

In the GLOBE Clouds protocol and GLOBE Observer mobile app, members can report if the sky is “overcast” or “obscured”. But what is the difference? Below are some tips to help! All the photographs featured were collected by GLOBE observers.

Obscured and overcast can be confusing, but the below information will help clarify these terms. 

Definitions

Overcast: The sky is completely covered by clouds (cloud cover greater than 90%). This means that there is little or no blue sky. When it is overcast, the clouds are stratus clouds. Stratus are gray or grayish white.

Obscured: Something is blocking both the view of the sky and the clouds. This could be dust, haze (pollution), smoke, volcanic ash or even heavy rain or snow. Snow will appear white, but other obscurations may give the sky a brownish or orangish hue.

How to Take Photographs

For overcast skies, tilt the camera at a 14-degree angle up at the sky. The GLOBE Observer app can help by automatically taking the photo when the device is titled at the right angle.

For obscured skies, look straight ahead at the horizon, the same way as when making visibility reports. Those using the GLOBE Observer app should follow these steps to submit a photograph of the horizon. The example in these steps is for dust. Make sure to select the obscuration that was actually observed (for example, smoke or haze).

What If There Is a Mix?

Helpful tips to make cloud observations.