Solar Cycle 25. I Was Wrong!!

Happy Meteorological Fall,

I hope everyone had a great Summer. It wasn't as hot this year here in North Central Texas. We had to endure about 20 days between 100 and 105.  Last year we had about 30 days from 105 to 110.  I don't handle heat in my older age, so I looked for opportunities to stay cool in the A/C by having fun on the radios.

This Summer we were blessed (or cursed depending on how you see it) with the most Solar Activity in 20-22 years. By August, we saw the highest Solar Activity in 33 years. We saw an almost daily M-Class Solar Flare, some days multiple ones. X-Class flares did occur, but were never overly powerful as had occurred 22-24 years prior. Rather than some VHF Aurora, there were way too many radio blackouts and a healthy decline in Sporadic Es. There was still Es, just not consistent. On the other hand, there were many times that 20 Meters was open all night and 15 Meters was open as late as Midnight.

During the Summer, F2 MUF declines. When there is high solar activity, 20 Meters is the highest frequency in which can be open all night. Long distant propagation on 15, 10 and even 6 Meters will only be dependent on solar events like flares and Coronal Mass Ejections (CME).  Sporadic Es still occur, but are highly erratic in their appearance. On VHF there is a phenomena that appears called FAI (Field Aligned Irregularities), but had been non-existent for over 20 years. Solar Cycle 24 was lousy.

What Has Happened

The last time I posted, it appeared that the Solar Cycle had peaked. Despite the trends indicating it had, in addition to the actions of past Solar Cycles (4 years incline, 7 years decline) there was a good possibility the Cycle was done. So I thought ......

I am an optimus. The past three Solar Cycles had dual peaks. I was hopeful that the same would occur for this one. What it appears is that the second peak is MUCH better.

Almost as soon as I posted last January, the Solar activity began to increase again. Once we got into the Summer, it has really taken off.

Solar Cycle Trends

The graph displays the monthly observed 10.7 cm Solar Flux since the accepted month that the Solar Cycle began.
Blue line is the current Cycle (25).
Red line is the past Cycle (24).
Green line is Cycle 23.
A polynomial trendline (line of best fit) to an odd power (3) is used to show an increase correlation for those events. The graphs shows 57 months in the Cycles.

The trendlines of both Solar Cycles 23 and 24 have shown that their decline had begun on or about 48  months. For the current Cycle although monthly values had begun a decline at 45 months, by the 53rd month it rapidly increased.  It has not slowed down since.

The August 2024 monthly value was the highest since February 1991 (Solar Cycle 22). It has exceeded all monthly values experienced in Cycles 23 and 24.

6-Month Moving Average

A six-month moving average also shows what is happening in the immediate versus what has happened overall.

The moving average for this Cycle shows that it has approached a level close to what was experienced during the Cycle 23 peak. Obviously, this Cycle has far exceeded the past Solar Cycle (24) and what was predicted for this one.

What to Expect

Summer has ended. Fall begins. The F2 MUF will gradually rise each week and peak around the Winter Solstice. If Solar activity remains close to current values we should see exciting conditions from 15 Meters all the way up to 6 Meters.

The graph displays the potential F2 MUF for an optimum single hop reflection for a Solar Flux level of 190. The Earth has experienced levels far in excess for many weeks this Summer.

It's time to take advantage. This Solar Cycle has been unpredictable and for us in the Northern Hemisphere not very timely.  Don't waste it this Winter.

73 Art K7DWI/5