Mark; thanks for that link to Helio4cast!
Those first two graphs are crackers! Why is the NOAA prediction suddenly changed to a 6 month time shift? just to fit it to the data? You should never fit your theory to the data, if the theory is right it will fit the data itself.
Hi Alexandra,
Good question, however - It doesn't appear the 6 month shift was done to just to fit the data - even though that's what it says. I remembered that the
consensus forecast was for cycle 25 to begin in April 2020
+/- 6 months:
- Cycle 25 consensus forecast.jpg (158 KiB) Viewed 2562 times
Therefore the forecast was also apparently shifted to align the end of cycle 24 with the beginning of cycle 25 in late November or early December 2019 from the original prediction of April 2020:
- Cycles_24_25_minimum.png (179.49 KiB) Viewed 2573 times
The Helio4cast graph shows that when corrected 6 months for the timing of the end of cycle 24 and the beginning of cycle 25, the recent data showing an increase in sunspot activity might still be within the upper range of the original NOAA/NASA/ISES prediction, and the mean activity also appears to be tracking well with the original prediction. Therefore we will need several more months to see whether the McIntosh et.al. prediction begins to show if it might be the more accurate prediction:
- cycle25_prediction_focus.png (172.12 KiB) Viewed 2573 times
For now at least it appears the original consensus forecast is still quite valid, and the
spaceweather.com sunspot update report which initiated this post was based on an inaccurate start date for cycle 25.