Solar activity is currently at relatively low levels with numerous C-Class flares detected around sprawling sunspot 1861. The active region continues to evolve magnetically as it rotates towards the west limb. There will remain a chance for an isolated M-Class event within the next 24 hours. All other regions, including formerly active sunspot 1865 remain stable. A new sunspot is forming quickly in the southeast quadrant and should be monitored for further growth. Old sunspot 1850 rotated back into view off the east limb and appears to be stable at this time.
Solar activity was low. Region 1865 (S22W37, Dso/beta-delta) and Region 1861 (S10W57, Dhc/beta-gamma) were responsible for multiple C-class flares. Region 1861 produced a C1/Sf flare at 16/0920 UTC with associated weak types II (est. shock speed 548 km/s) and IV radio sweeps. After analysis, the associated CME was determined to have a narrow south-western trajectory unlikely to be geoeffective. .Forecast... Solar activity is expected to be low with a chance for an M-class (R1-R2 Minor to Moderate) flare for the forecast period (17-19 Oct). The most likely regions for M-class flare activity continue to be Regions 1861 and 1865. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels. The greater than 10 MeV proton flux at geosynchronous orbit was at background levels. .Forecast... The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate to high levels for the forecast period (17-19 Oct). The greater than 10 MeV proton flux at geosynchronous orbit is expected to remain at background levels. Solar Wind .24 hr Summary... Solar wind parameters, measured at the ACE spacecraft, indicated the remnant presence of a coronal hole high-speed stream (CH HSS). Speed decreased from near 550 km/s at the beginning of the period to just over 460 km/s by the end of the period. IMF total field held steady at around 4 nT, while IMF Bz intermittently dipped southward briefly as low as -4 nT. Phi angle remained in a positive (Away) orientation throughout the period. .Forecast... Enhanced solar wind variability is expected to persist for the next two days (17-18 Oct) from combined effects of residual CH HSS and the anticipated arrival of the CME from 13 Oct, now expected early on day one (17 Oct). A return to ambient conditions is forecast for day three (19 Oct).