Sun fires X1.7 flare aimed straight at Earth

An X1.7 flare erupted from the Sun on 9 November, peaking at 07:33 UTC, resulting in a radio blackout on the Sunlit side of the Earth. The associated asymmetric halo coronal mass ejection (CME) has an estimated velocity of around 744 km/s, and is expected to wash over the Earth between 11 and 12 November, resulting in a minor to moderate geomagnetic storm. A CME that left the Sun on 7 November is already causing an ongoing geomagnetic storm at the Earth. The source of the X1.7 flare was a cluster of sunspots designated by the US National Oceanic and Atmospheric Administration (NOAA) as Active Region 4274 and by the Solar Influences Data Analysis Centre (SIDC) operated by the Royal Observatory of Belgium as Sunspot Group 687. 

AR 4274 rotated into view last week, after growing in size and complexity on the far side of the Sun, and fired off an X1.8 solar flare, the first flare of that intensity since June. According to the SIDC, "SIDC Sunspot Group 687 (NOAA Active Region 4274) is the largest region on disk, the most magnetically complex (Beta-Gamma-Delta) and produced most of the flaring activity in the last 24 hours." According to the Center of Excellence in Space Sciences India (CESSI), the space weather service of India hosted by the Indian Institute of Science Education and Research (IISER) in Kolkata, "We can now confirm that a halo CME was launched earlier today - associated with the X class flare from AR 14274 near central meridian. It is Earth directed. Further updates will be provided post appropriate data analysis. Brace for impact!

According to the British Geological Survey, "Geomagnetic activity reached STORM G2 levels overnight due to the high-speed solar wind stream from a coronal hole and a coronal mass ejection (CME) impact early on the 7th." According to the forecast of the UK Met Office, "Ongoing CME effects are likely at first on day 1 (10 Nov), with a low chance of a further slight arrival later in the day. These from the Moderate flare and filament eruption CMEs on 07 Nov. A more significant arrival is then expected during the second half of day 2 (11 Nov) from the Strong flare CME observed on 09 Nov, with any activity likely continuing into day 3 (12 Nov)." According to the Space Weather Prediction Centre (SWPC) operated by the NOAA, "The solar wind environment is likely to become mildly enhanced with CME influences on 10 Nov as the 07 Nov CME passes in close proximity to Earth. Stronger solar wind disturbances are likely over 11-12 Nov due to the anticipated arrival of the 09 Nov asymmetric halo CME."