2003 Halloween solar storms

Halloween solar storms, 2003
Composite image showing aurorae over northern Europe, taken by DMSP on October 30, 2003
Associated solar active region
NOAA region no.10486
Largest SXR flaresX40+
G5 "Extreme" geomagnetic storm
G-scale (NOAA/SWPC)
Initial onsetOctober 2003 (2003-10)
DissipatedNovember 2003 (2003-11)
Highest Kp-index9
Highest Ap-index204
Lowest Dst−383 nT
ImpactsElectrical faults and wear to various satellites; satellite communications blackouts; localized power outage in Sweden

Part of solar cycle 23

The Halloween solar storms were a series of solar storms involving solar flares and coronal mass ejections that occurred from mid-October to early November 2003, peaking around October 28–29. This series of storms generated the largest solar flare ever recorded by the GOES system, modeled as strong as X45 (initially estimated at X28 due to saturation of GOES' detectors).