This week our Sun shows us just how far into the declining phase we have come! Our first spotless disk arrived September 19. Although it lasted less than a day, it marks a milestone for Cycle 25. Compared to average cycles, the first spotless sign typically means we have less than three years before solar minimum. This signature is right on target with predictions, which show minimum in 2029. Whether the Sun will continue the descent towards minimum at an accelerated pace has yet to be seen (the latest predictions have us 6-10 months ahead of schedule). But for the moment, this is a good indicator of things to come.

As for the current activity, we have some fast solar wind coming. It should arrive starting late on September 23 into the 24th, so aurora photographers, especially at high latitudes, keep on the lookout for aurora. Mid-latitude watchers might have more of a challenge to catch some shows, but substorms are possible, especially on the 24th. As for amateur radio operators and GPS users, the dayside radio bands have been pretty quiet over this past week, but noise is slowly returning– so much for our spotless sun. Not only is Region 4534 beginning to fire large C-class flares, but a region on the East limb is also firing big flares and launching solar storms. Radio operators should expect the R1-R2-level radio blackout risk to rise throughout the week. GPS users should stay vigilant, especially if flare activity rises while the fast solar wind hits, because the sudden changes could make the upper atmosphere more turbulent.