How to read it

The word

Search a place, or use where you are. The large word is the reading for the hour you opened.

Quiet. Little should show, the sky is too bright, cloud covers it, or this place is too far from the oval.

Faint. A glow may sit low on the poleward horizon.

Likely. The oval reaches this sky. Copper, the same way Frost marks 60% or more.

Strong. A strong aurora on this sky. Copper as well.

The bars

A row runs through the dark hours, dusk to dawn. Taller means a stronger reading. Copper is Likely or Strong. A dot is true dark, when twilight has left the sky.

Tap a bar to read that hour on its own. Tonight, tomorrow night, and the night after each take their strongest hour.

Opened from Night Glass, the hour matches the link: the same place, the same time.

What changes the word

Planetary Kp, from NOAA, in three-hour blocks. It cannot time a substorm.

Daylight and bright twilight knock the reading down. A bright moon can take the edge off a faint glow. Thick cloud covers it. Broken cloud steps it down one word.

It is a forecast of the sky, not a promise of lights. If you are out at night, treat the ground and the weather as their own questions.