Revised Official Forecast for the Apex of Earth’s Current Solar Cycle Now In-Line With Maverick ‘Termination Event’ Prediction

NOAA’s Space Weather Prediction Center (SWPC) has revised their forecast for the upcoming maximum for solar cycle 25, now expected to peak at some point before October of next year instead of sometime in 2025; additionally, next year’s maximum will be much “stronger” than what was previously expected. Although NOAA’s initial projection was accepted as the official forecast, the conditions that are being observed now were accurately predicted more than two years ago by a National Center for Atmospheric Research (NCAR) team that used the occurrence of “termination events” in the magnetic field of the Sun to make their projections.

This revised prediction, released by the SWPC on October 25, states that “solar activity will increase more quickly and peak at a higher level than that predicted by an expert panel in December 2019. The updated prediction now calls for Solar Cycle 25 to peak between January and October of 2024, with a maximum sunspot number between 137 and 173.”

This revised prediction comes after the Sun’s activity since the current cycle, solar cycle 25, proved to be far more active since it got underway in December 2019 than previously forecast. The current period was expected to peak sometime in 2025 while only exhibiting mild solar activity, much like cycle 24, according to the predictions made by the previously-mentioned panel commissioned by NOAA, NASA, and the International Space Environmental Service (ISES).

This new forecast is more in line with a different analysis produced in 2021 by the National Center for Atmospheric Research (NCAR) that forecast a more active Sun during this cycle, based on what NCAR Deputy Director Scott McIntosh described as “termination events” that occur when the oppositely-charged magnetic bands that migrate from the Sun’s poles meet at the equator, cancelling—or terminating—one-another. This termination event appears to be linked to the mid-cycle flip of the Sun’s magnetic field when north becomes south, and south becomes north. NCAR also predicted that solar cycle 25 would peak sometime in 2024, a year earlier than what the official forecast called for.

In response to this change in their forecast, the SWPC has also announced that they will be shifting to a more flexible reporting format, of which will issue monthly updates; this reporting is traditionally only done once per solar cycle, with the cycle 25’s forecast not having been updated since 2019.

“We expect that our new experimental forecast will be much more accurate than the 2019 panel prediction and, unlike previous solar cycle predictions, it will be continuously updated on a monthly basis as new sunspot observations become available,” according to SWPC solar cycle lead Mark Miesch, a scientist with the University of Colorado, Boulder. “It’s a pretty significant change.”

It’s important to bear in mind that despite predictions of a stronger solar cycle, this is only in comparison to solar cycle 24’s record calm: the Sun’s activity is still extremely low, having declined since its most recent long-term peak in the mid-1950s. For context, the forecast maximum sunspot count for this cycle of between 137 and 173 still falls far short of the 285 spots recorded for solar cycle 19 (April 1954 to October 1964).

Regardless, it would be unwise to let our guard down, as  the most intense geomagnetic storm in recorded history, the 1859 Carrington Event, occurred during an otherwise-average solar cycle, an event that, if it were to happen today, would be devastating to our modern electrical grid. Whitley outlines the danger presented by solar storms of that magnitude—and what needs to be done to weather such a storm—in his 2012 ebook Solar Flares: What You Need to Know.