Propagation News – 27 November 2022

| November 25, 2022

We dodged a bullet last week when a large coronal hole failed to produce a geomagnetic disturbance. Despite many predictions that we could expect an upturn in the Kp index, it looks like the solar wind missed the Earth, probably because the hole was too low in the Sun’s southern hemisphere.

As a result the Kp index never went higher than 4, actually 3.67 globally, and things remained calm. This was good news for HF, although a low solar flux index below 120 all week was nothing to get excited about. At the same time, the improvement in low-band conditions, as we head into late Autumn, is making up for it. Top Band contacts have been recorded with 3B8 Mauritius, and Peter, G3PHO has even made it into the USA in the late afternoon on 160m FT8.

So, if you’ve never worked much on Top Band, and you have the antenna for it, give it a try. Failing that, try the top end of 80m SSB around sunrise in the UK for contacts with the USA.

Next week, NOAA predicts that the solar flux index will remain around the 120-125 mark. The good news is that there are no large coronal holes currently visible and there have only been minor C-class flares with CMEs that have not been Earth-directed, so geomagnetic conditions are likely to be good. That is, at least until the 1st of December when we have a predicted Kp index of four, which may disrupt contacts mainly on polar paths.

This is good news for this weekend’s CQ Worldwide CW contest, which is a great opportunity for you to up your country totals or for your Worked All States award.

Now a footnote for those occasions when the graphs are not updating. It can be a local effect at one of the stations, such as Chilton, which has been offline recently. Usually selecting one of the tick boxes in the top right of the graphs will show Fairford or Dourbes when available.

However, last week and maybe still, we have a complete blank for all three ionosonde station plots, which is much more likely to be a server issue in the States where the data is hosted. You can check the Propquest server is working by selecting the “Archive” or “Averages” tabs.  In any event, the ionosonde data plots will come back automatically once any issues have been resolved.

VHF and up

The unsettled spell of weather continues into the first half of next week so could provide some further rain scatter opportunities on the GHz Bands.

The broad south-westerly pattern may well switch over to an easterly after midweek as high pressure builds across Scotland. This could bring a return of Tropo for some parts, but looks a bit weak, while the south will continue to be affected by low-pressure systems.

It will feel colder, with some models hinting at wintry conditions being a possibility, so wrap up well if you plan to do any portable operation!

The Alpha Monocerotids meteor shower noted last week is over but the small November Orionids, active until 6 December, reaches its peak on Monday the 28 November.

Get ready for the big Geminids meteor shower in December. It commences on 4 December reaching a ZHR of over 100 between the 14 and 15 December. More about this closer to the shower peak.

Moon declination is increasing again and goes positive on Friday. So Moon windows will lengthen and zenith angles will increase. Path losses, on the other hand, start to increase again this week after last Friday’s perigee. We have to wait until mid-2026 before maximum declination coincides with the lowest path loss, but we are moving in that direction again. 144MHz sky noise is low all week, not getting above 300 Kelvin until next Sunday.

Category: GB2RS Propagation News