Propagation News – 19 January 2025
It looks like the lull in sunspot activity is coming to an end as the solar flux index rose to 174 on Thursday 16 January, after a week in the 150s and 160s.
The Sun was fairly bare, but there are now signs of more sunspot activity rotating into view.
There have been no X-class flares in the past seven days and only one M-class event. This has meant that the Kp index has been low, thanks to a lack of associated coronal mass ejections. There were four during one three-hour period on the 13 January.
As a result, HF conditions have not been too bad with daytime maximum useable frequencies, or MUFs for short, over 3,000km regularly exceeding 24 and even 28MHz at times. However, night time MUFs are still in the doldrums, often struggling to get above 5MHz over a 3,000km path. This will no doubt change as we head towards spring.
DX on the bands recently has included S01WS in Western Sahara and UP7WWA in Kazakhstan, both on 28MHz CW. Closer to home we have had GB200LB celebrating the bicentenary of the invention of the Braille code and GB1GKA commemorating the 100th anniversary of the Portishead Radio receiving station, callsign GKA, at Highbridge, Somerset. Both of these stations were active on the 20, 17, 15 and 10m bands using CW.
At the other end of the bands, Kev, VK6LW has been heard on 1822kHz from Western Australia at his sunrise at 2112UTC, as has Robert, DU7ET in the Philippines at 2200UTC. January is a great month for top band contacts.
Next week, NOAA predicts that the solar flux index will remain in the 160 to 175 range. Geomagnetic conditions are predicted to be good with a maximum Kp index of 3.
As always, keep an eye on solarham.com for news of solar flares and coronal mass ejections, which could easily send the Kp index higher and the MUFs lower.
VHF and up
The current spell of high pressure has served us well with some good tropo paths around the edge of the high into Spain and Portugal and even beyond to Madeira.
This has shown how effective long maritime ducts can be around the edge of areas of high pressure.
On the 16 January, the Atlantic was taking over the agenda and low pressure near Scotland was pushing a weakening front into north-western Britain as the high retreated east into Europe.
The rest of the coming week has other lows bringing some rain or showers – especially to the north-west of the UK where it will become quite windy again. On Wednesday 15 January, weather models suggested a small high may return to the southern part of the country.
We are in a rather unsettled weather period with some limited rain scatter potential for the GHz bands. Meteor scatter is also a bit thin with just a possibility of scatter via the Gamma Ursae Minorids, which peaked yesterday, the 18 January. However, the number of meteors is at a very low rate and so is not a great option.
Next, we move onto aurora and there continue to be examples of alerts suggesting minor events. Generally, though, spring is usually a better time, so there’s still a while to wait.
Saturday 11 January brought a welcome out-of-season Sporadic-E opening to Poland, and then the Balkans, on 50MHz lasting around three and a half hours from 1200UTC.
Another good piece of news is the return of ionosonde data for the propquest.co.uk website after a few missing days. This is a timely opportunity to thank all those who maintain the professional data sets that allow us amateurs to see what the bands are doing.
Moon declination is positive, going negative this Sunday. Moon windows will shorten, and peak Moon elevations fall. Path losses continue to increase as we approach apogee on Tuesday. 144MHz sky noise is low all week.
Category: GB2RS Propagation News
