W3LPL's forecast for upcoming Solar Cycle 25 - Apr 2021

Frank Donovan, W3LPL is one of the top contesters in the USA and is a key forecaster of upcoming conditions on the HF amateur radio bands.

In a recent forecast (April 2021), he made a forecast about how good upcoming Solar Cycle 25 would be based on the Solar Flux numbers at the end of December 2021. I have put together a graphic which shows this above. The starting point for April 2021 is a solar flux index of 77 which is roughly the average for the month.

W3LPL wrote... “If the SFI persists below 90 through December 2021, then propagation should improve gradually until a solar maximum weaker than Cycle 24’s arrives in 2024.

If the SFI persists above 110 through December 2021, then propagation should improve rapidly until a solar maximum similar to Cycle 24’s arrives in 2024.

“If the SFI persists above 125 through December 2021, then propagation is likely to improve more rapidly until a solar maximum stronger than Cycle 24’s arrives in 2024.”

(SFI = Solar Flux Index)

As with everything on the sun, there is always an amount of uncertainty in solar forecasts but it will be interesting to revisit this at the end of the year and see where we're at.

Link...
1) K7RA Solar Update - 23rd April 2021

Scientist predicts the peak of the next Solar Cycle will be one year earlier than expected

In a recent interview, Lisa Upton of Space Systems Research Corporation and co-chair of the NOAA/NASA Solar Cycle 25 Prediction Panel said...  “The sun is performing as we expected–maybe even a little better. In 2019, the panel predicted that Solar Cycle 25 would peak in July 2025 (± 8 months) with a maximum sunspot count of 115 ± 10. The current behavior of the sun is consistent with an early onset near the beginning of our predicted range.”

The diagram above shows the new solar cycle running ahead of schedule. If it continues like this then Solar Cycle 25 may peak in 2024, a year earlier than expected.

As with all solar predictions, only time will tell how accurate they are.

Sun starts to sizzle as solar flux hits 100

After a long solar minimum slumber, the sun has really begun to wake up in the last few weeks. On the 24th of November 2020, the solar flux hit 100 for the first time in about three years. The last time the solar flux was over 100 was back on the 10th of September 2017.

The photo above shows some of the sunspots on the solar disk including region 2786 which has a dark core which is slight larger than planet Earth.

The chart below shows the dramatic change in the solar flux in the last 12-months...

The biggest change in the conditions on the HF bands is that the higher bands like 10-metres are now opening. At the end of 2019 at the sunspot minimum, there were some hints of propagation but mostly on north-south paths. Fast forward to the 26th of November 2020, you can see that there was a nice opening to the USA on the 28 MHz band.

It's been a long time since I heard signals from Texas on 28 MHz via F2 propagation.