Propagation News – 1 December 2024

Last weekend’s CQWW CW contest was a reminder of just how good HF propagation can be near sunspot maximum.

The whole world was workable on the contest bands up to 10 metres, including the Far East, Australasia, the Caribbean and South America. It was a great opportunity to increase your DXCC total and have fun at the same time.

This week’s solar flux index crept back above 200 again, peaking at 225 as this report was being prepared. Geomagnetic conditions have been surprisingly good over the past seven days with a peak Kp index of 3.67 on the 24 November.

There have been no X-class solar flares, but there has been a total of 13 M-class and 54 minor C-class flares over the past seven days. There have been coronal mass ejections, notably on the 25 November, but they have not been Earth-directed as of the 28 November.

So, to summarise, HF conditions have been pretty good.

We are now entering the Winter period for HF propagation, which tends to favour the low bands. So 160m, 80m and 40m come into their own and night-time DXing becomes the norm. Look for greyline openings to the west at sunrise on 80m and 160m, and also short, but good, openings on 40m in the late afternoon.

Night-time may bring good DX on 80m and 40m, including the Caribbean and South America.

NOAA predicts that the SFI will remain in the low 200s next week, and while geomagnetic conditions are forecast to be good at first, the Kp index may rise to four on the 4 to 6 December. This could result in reduced MUFs until the Kp index recovers.

VHF and up 

The unsettled theme continues through most of the next week or two. The only signs of slightly enhanced prospects for Tropo are as we close this week, and even that is restricted to some eastern areas for paths across the North Sea.

A second option may temporarily appear around the middle of the coming week as a weak high crosses southern areas, but this one looks to be a cold high and probably not so good as a vehicle for Tropo.

The meteor scatter prospects are aided by the last throes of the Leonids which fade away by this weekend, and the Orionids which peaked on Thursday 28 November, but last through the coming week.

The unsettled weather should offer some useful GHz bands rain or snow scatter, since there will be several active weather systems around. This early in the winter is a great time for strong shower activity around the still relatively warmer seas.

The auroral prospects are worth checking after recent activity. Look for watery-sounding signals on the LF bands as a good clue along with Kp index values greater than four.

Last week saw some fleeting signs of Sporadic E on the Dourbes ionosonde graphs on propquest.co.uk, especially on Monday 25 November. This occurred typically around the middle of the day and was probably driven by the very strong jet stream and the current meteor activity.

The Moon’s declination is negative, reaching minus 28 degrees on Monday and we are close to eclipse on Sunday. That’s followed by two days of high 144MHz sky noise, so with path losses still high, EME operators should probably take the opportunity to check their antennas after last week’s gale.

Category: GB2RS Propagation News