NOAA Geomagnetic Storm Scale
The G-scale (G1–G5) classifies storm severity. G3 and above produce visible aurora for large populations.
Weak power grid fluctuations. Aurora visible at high latitudes (65°N+). Animals may be affected by geomagnetic disturbances.
Power systems may trip. Aurora visible at 60°N+. High-frequency radio propagation fades at higher latitudes.
Power systems may trip. Satellite navigation issues. Aurora visible as far south as 50°N (UK, Germany, northern USA).
Widespread power control problems. Pipeline current irregularities. Aurora visible down to 45°N — parts of central Europe and the northern USA.
Widespread power outages possible. GPS unusable. Aurora can be seen near the equator. Extremely rare — only a handful per solar cycle.
Storm Alert Types Explained
NOAA issues three types of space weather alerts with different lead times
Issued 1–3 days in advance when conditions may produce a storm. Based on CME trajectory analysis.
Storm expected within 3 hours. Issued when solar wind data confirms imminent impact.
Storm has already begun. Real-time KP data has exceeded a defined threshold.
Where the Data Comes From
AuroraVision uses the same government satellite data that powers NOAA official alerts
DSCOVR Satellite
L1 Lagrange point — 60 min warning before CME arrival
SOHO / SDO
Tracks sunspot regions and solar flares in real-time
GOES-R Series
Classifies flares A, B, C, M, X — X-class cause G3+ storms
NOAA SWPC
Issues G1–G5 geomagnetic storm watches, warnings, alerts