When Solar Cycle 25 began in 2020, leading forecasters thought it would be weak and slow to develop. Fast forward three years: NOAA is now predicting a quicker, stronger solar cycle. The revised forecast, published on 19 October 2023, shows Solar Max coming sometime between January and October 2024.

NOAA’s original prediction for Solar Cycle 25 is shown in pink, the broad band indicating the uncertainty of the forecast. It has become clear in recent years that the original prediction was too low, which prompted NOAA to issue a new one. The magenta line  traces the new forecast and takes into account recent high sunspot counts.

Uncertainties in the new forecast are bounded by different shades of magenta. There is roughly a 25% chance that the smoothed sunspot number will fall within the dark-shaded region; a 50% chance it will fall in the medium-shaded region; and a 75% chance it will fall in the lightest of the shaded regions.

If this new forecast is correct, Solar Cycle 25 could land in the ballpark of Solar Cycle 23, which peaked in 2000-2001, and produced the famous Halloween Storms of 2003. However, the odds still favour Solar Cycle 25 being a bit weaker than Solar Cycle 23. Either way, next year’s Solar Max could be potent.

NOAA plans to update this new forecast every month.