Thursday, September 17th marked a milestone in terms of the solar flux index. On this day the SFI fell to 100. This is more psychological than important, but it is a sign that the SFI is falling from the dizzy heights of more than 300 that it reached at the height of solar cycle 25 two years ago.
The SFI briefly dipped below 100 to 99 on August 13, 2026, but I think that this time it won’t be long before we see it dropping further.
The declining SFI has been helped somewhat by better ionospheric conditions as we head towards October.
The lower SFI has also been slightly compensated for by relatively good geomagnetic conditions. The Kp index hit a peak of four on the 14th, but has otherwise been around one or two.
Daytime MUFs over 3,000km have been hovering around 21MHz and nighttime MUFs over 3,000km have been around 7-10MHz. But don’t ignore 24MHz as we may see the occasional daylight DX opening. We may expect the daytime MUFs to increase slightly as the month progresses.
DX to be worked this week includes 5W0AF (Samoa), RI1FJZ (Franz Josef Land), FR/F1TEQ and FH/F1TEQ (Reunion and Mayotte), KH8WW (American Samoa), PJ2/K5SL (Curaçao) and 8Q7JH (Maldives). Later in the week look for KH0/JR1FKR (Saipan) and N7NU/VP9 and VP9I (Bermuda). So lots of DX to search for next week.
We expect the SFI to hover around the 100 mark over the next seven days, but watch out for poor geomagnetic conditions on September 24-27 when NOAA forecasts that the Kp index could hit five.
And finally, I look forward to meeting you at the Newark Hamfest on Friday and Saturday this week.
HF and up
The period of unsettled weather that has brought a little much-needed rain is just about done for a while, since it looks like high pressure will build across southern UK during the second half of the weekend.
It may even produce some ridging over northern Britain, so there is a good chance for Tropo in many areas at some stage during the coming week.
Admittedly, the high does gradually edge away to the east by the end of the week, but will still be close enough to provide further lift conditions, especially across the North Sea to the Baltic and south to France.
Don’t forget to try calling CQ on SSB or CW in case conditions are up, it’s easy to miss a new square unless you are checking remote beacons to see how the lift is developing. The far northwest of the UK will have some occasional rain at times and may miss out on the enhanced lift conditions, especially after midweek.
Meteor scatter is again largely a case of trying to catch the best of any random activity, which means checking conditions in the early hours of the morning. The solar activity has produced slightly elevated geomagnetic activity with a Kp index up to Kp=4 at times and with a possibility of a minor storm in the second half of the last week, it probably should remain a watching brief in case we find an unexpected auroral opening, which tend to favour the equinoxes due to the Russell-McPherron effect.
EME now, and Moon declination starts rising again after its lowest point on September 18. Meanwhile, path losses start falling again after apogee, also on the 18th. 144 MHz sky noise starts the weekend high, falling back to low by Tuesday the 22nd where it remains for the rest of the week.