Methodology
Forecast Limitations
Aurora forecasting is uncertain, and the uncertainty increases with time and local specificity.
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Space-weather uncertainty
A solar event can miss Earth, arrive earlier or later than expected, or carry a magnetic-field orientation that changes its geomagnetic effect. NOAA OVATION provides a short-range model based on current solar-wind conditions. Longer-range Kp and geomagnetic outlooks have less spatial and temporal precision.
Visibility is more than activity
Aurora is not useful for visual observing in daylight. Clouds, haze, light pollution, terrain, moonlight and viewing direction can affect what reaches an observer. A strong space-weather signal does not guarantee a clear, dark local sky.
Safety boundary
GreenHalos does not guarantee visibility and is not an official warning service. Consult NOAA SWPC and the relevant local authority for official operational information.
Review how confidence changes across the aurora forecast horizons.
When viewing time approaches, return to current aurora activity.