Propagation News – 5 November 2023
The last two weeks have not been too bad for HF propagation, but not particularly good either. The solar flux index hit lows of 119 on the 22 October and 121 on the 24th, but subsequently recovered and stood at 159 on Thursday 2 November.
This at least allayed the fears of some amateurs that Solar Cycle 25 was over!
But, as the solar flux index rose, geomagnetic conditions became slightly unsettled. The maximum Kp index was 4.67 on the 29 October but has subsequently recovered to between 1 and 3.
This didn’t affect HF too much with the daylight maximum useable frequency over 3,000km remaining steadfastly over 28MHz all week, even hitting 43MHz on Thursday the 2 November.
As a result, the bands have been humming with lots of DX being worked. Phil, GU0SUP reports working Jan, E51JAN on the North Cook Islands on 12m FT8 Fox and Hound mode at around 1630UTC. He said that, as it was almost dark, he didn’t expect to hear anything, but had a good copy on him at 190 degrees, so gave him a call. He came straight back.
Phil said that this was a big surprise, and he is not sure how it worked. It was quite a skewed path, with pretty much no copy on the real headings, short or long path.
He also worked YJ0TT Vanuatu on 10m at 0843UTC that morning, and later at 1741UTC on 20m FT8 Fox and Hound mode. As Phil said: “Two new DXCCs in one day!” So, the moral of the story is to keep on trying – you never know what you will work!
Next week NOAA predicts that the solar flux index will decline slightly to the 130s. A bigger problem is a massive coronal hole, which is rotating into an Earth-facing position. This could cause the Kp index to rise, possibly on Sunday 5 or Monday 6 November .
NOAA also predicts a geomagnetic disturbance on November 9 November when the Kp index could rise to four. Otherwise, it suggests fairly settled conditions and a general Kp index of two. As always, keep an eye on solarham.net for up-to-date information.
VHF and up
The current spell of unsettled weather with areas of low pressure, strong winds and rain or showers will probably remain over the coming week to the 12 November. This again suggests that Tropo will not be a feature of VHF/UHF operating and perhaps there are just a few weak options for rain scatter to lift the mood.
Since comments last week about out-of-season Sporadic-E propagation, we are still getting weak Sporadic-E signals on the graph plots on propquest.co.uk which peaked at 5.35MHz at Dourbes on Wednesday 1 November, at 1700UTC. This may have been enough to produce paths on 6m band data modes. Favoured times of day for these chance events are typically around 10am or 5pm.
Meteor scatter prospects are still good since the decaying Orionids are probably lingering up until the 7th, and we approach the peak of the Taurids around the 12 November. The week after, we’ll be looking forward to the November Leonids. So if you’ve not tried meteor scatter yet, this may be a good time to read up on modes, frequencies and operating techniques.
Lastly, a brief mention of aurora, which is always possible given a decent coronal hole event like last week. So keep a check on the Kp index for larger values above, say, 5.
For EME operators, Moon declination is at maximum this weekend, meaning long Moon windows and high Moon elevation. Path losses are at their highest over the period due to apogee on Tuesday 6 November and 144MHz sky noise is low all week.
Category: GB2RS Propagation News
