Propagation News – 25 October 2020

The last week was dominated by sunspot region 2776, which pushed the solar flux index to 75. Geomagnetically, it was a mixed bag though, with the Kp index peaking at four on Wednesday, but otherwise being relatively quiet and showing zero on Tuesday. The sunspots, plus the October seasonal enhancement, meant that the HF bands were quite active. There were reports of Australia being worked from the UK on 10m FT8. Alek, VK6APK was worked at 0920UTC by Tony, G4HZW. Mario, FR4QT on Reunion Island was also worked on 28.380MHz SSB by Gary, G0FWX, according to the 10m UK Net Facebook group. If you like 10 metre operation the group is definitely worth signing up to. These 10 metre contacts bode well for the future and we look forward to other reports of VK/ZL as the solar cycle progresses.

Next week, NOAA predicts the solar flux index will be the range 72-74. Sunspot region 2776 will have almost rotated off the visible disk by the time this report is published and there are no other spots at the moment. However, it does look like we are in for a disturbed weekend with poor geomagnetic conditions. This is due to a large polar coronal hole on the solar surface that has returned after a 27 day rotation and which could cause the Kp index to rise to five. The solar wind will likely increase in speed and density, resulting in an adverse effect on the ionosphere after a potential pre-auroral enhancement.

Expect maximum usable frequencies to decline and conditions to be poor this weekend. Do look out for potential 10 metre auroral contacts though.
VHF and up:

We are about to enter a phase of very disturbed weather with a series of deep lows dominating the charts, especially in the nearby Atlantic. Their influence will bring strong winds and periods of heavy rain or showers. At long range it’s pointless to try to time such events precisely, but nonetheless the general characteristics suggest that tropo will again be a rare feature in the coming week, other than transient weak ridges between successive fronts or lows. On the upside, rain scatter could do rather well for the GHz bands.

The Moon’s declination is rising and goes positive on Thursday so Moon visibility windows will lengthen. The Moon reaches apogee on Friday where path losses are at maximum. 144MHz sky noise is low all week.

With the Kp index set to rise to five thanks to the returning coronal hole, it might be worth keeping an eye out for low-VHF auroral propagation again.

There are no significant meteor showers this week but get ready for the Leonids, peaking on 16 and 17 November. (rsgb.org)