Aurora oval
The ring-shaped region around the magnetic pole where aurora is most likely. During stronger storms it can brighten and expand toward lower latitudes.
Glossary
Northern lights forecast terms, explained
Use this page when a forecast says Kp, G2 watch, aurora oval, OVATION, cloud cover, or magnetic latitude and you just need the practical meaning.
Kp index
A global geomagnetic activity scale. Higher Kp often means aurora can reach farther south, but local visibility still depends on sky conditions.
G storm watch
A NOAA geomagnetic storm watch category. G2 or stronger watches are useful signals for more frequent aurora forecast checks.
NOAA OVATION
A NOAA aurora forecast model that estimates short-term aurora probability and intensity across a geographic grid.
Cloud cover
The share of the sky expected to be covered by clouds. Lower cloud cover improves local aurora viewing chances.
Northern horizon
The part of the sky facing north. Mid-latitude viewers often need a dark, open northern horizon to catch low aurora.
Camera-first aurora
A weak aurora setup where a phone or camera may capture color before the naked eye sees a clear display.
Stale-while-revalidate
A caching pattern where the page can show recent old data while the system refreshes the newest forecast in the background.