How AuroraOdds works

AuroraOdds is a visibility model, not a space-weather scoreboard. It asks whether aurora activity, darkness, clouds, and moonlight are all good enough at the same time for your exact coordinates.

Activity starts with NOAA OVATION, then checks whether your geomagnetic latitude is close enough to the auroral oval for the current Kp. Southward Bz and fast solar wind raise the activity factor; strongly northward Bz lowers it.

Darkness comes from the sun angle. Civil twilight or brighter is zero because the sky is too bright. Nautical and astronomical twilight ramp upward until the sun is below -18 degrees.

Clouds are the harshest local gate. Low cloud has the largest penalty, mid cloud is still important, and high cloud is a smaller penalty because thin cirrus does not always erase a bright display.

Moonlight is deliberately mild. A full moon hurts contrast, but bright aurora can still beat it, so the moon never dominates the forecast.

The final score is multiplicative. That is why a strong storm under solid cloud can still be close to zero, and why a clear night at low latitude can still be a long shot.