It hadn't occurred to me until lately that I hadn't updated the solar cycle and solar-terrestrial indices since last April. Guess I'm just getting out of touch with things.
The last update I posted was on April 28. A highlight I've posted on solar cycle updates has been the "Last solar cycles comparison" from Space Weather News, and produced by a group called solen.info. NOTE: the plot is at the first link, not the second (solen.info). Here is the current plot - with the exception of a short vertical line I added to point out the solar flux in that April 28th post.
It's pretty obvious that cycle 25 peaked around that green line. You'll notice that the highest Smoothed Sunspot Numbers (SSNs) are well above cycle 24, the previous cycle, but what you can't see on this graph is that cycle 24 had the lowest SSNs in the last hundred years, so cycle 25 has been quite a bit more active than 24 but that's just not saying much. "Hey, we're not the worst cycle in a hundred years!" A new feature in the April post was a prediction plot from NOAA. I include the current prediction and if you compare the plot from April to this one, you'll see that reality matches the prediction pretty well. The previous two curves on this plot, cycle 23 and 22, have two peaks. Cycle 23 is more noticeable with a deeper dip between the peaks than 22 has, 23 is almost one, relatively constant, high plateau of activity. Cycle 21 has an earlier peak than 23 and 25, and is a wider peak than the others, in addition to being the highest peak on the chart.
Looking at this plot, it's not surprising that there has been no repeat of some things I heard in 2024. You'll notice that the absolute peak of cycle 25 occurred during 2024. There were some days with very high solar flux in '24: the highest peak was in August as shown here: each black dot is one month, and the last dot in this plot is October's number (the plot shows "updated 2025-12-02" bottom right). I was regularly in the shack monitoring 6m activity much of the end of '24 and saw something I've never seen in my life, reports of ham stations in Alaska being heard within a few hundred miles of me. I've never heard an Alaskan signal make the last hop to Florida (on 6m), although a friend in Tennessee heard one, one time. Fifteen seconds out of a lifetime on the radio.
Is there a chance of hearing Alaska down here again - in this cycle? My guess is that if the current trend of having one cycle peak holds, no. The only thing that I think would help that is for a second peak of SSN, equal to or stronger than the previous peak forms. One thing that's in our favor is that cycle 25 is looking rather asymmetric. We thought it was peaking 20 months ago around 40 months into the cycle, but after remaining at relatively low SSN around month 50 after the cycle start it began moving toward a peak farther out (in time). What we don't know is how much longer the SSN will stay around where it is now. The second plot, on the cycle's progress pretty much predicts the SSN will be lower by 2026 after perhaps another quarter to half year around where it currently is. But those predicted movements are based on prior movements and I've never heard anyone address what causes the dual peaks in any detail of how to predict from them. Maybe they just don't know to predict dual cycle peaks.
A few of the times I've done this sort of post it was after a talk by Dr. Scott McIntosh, formerly a high-placed scientist with the National Center for Atmospheric Research (NCAR). Last year, Scott had moved to Lynker Space in the private sector. He's doing one of his update presentations on the Front Range 6 Meter Group on Wednesday, January 14. Those are carried live on their channel on YouTube but I have to say I've never watched one live and don't know if it's possible for non-members to watch it live. It usually shows up for general viewing on YouTube within a couple of days.
To borrow that wonderful quote from physicist Niels Bohr, “Prediction is very difficult, especially if it’s about the future.”
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