Propagation News – 29 October 2017

| October 27, 2017

Last week was once again a mixed bag, with good HF openings at times, and depressed maximum usable frequencies (MUF) at others. Quieter geomagnetic conditions on Sunday and Monday saw good openings up to and including 28MHz. But the arrival of solar material from a coronal hole on Tuesday saw much more unsettled conditions. An initial pre-auroral enhancement saw the good HF openings continue, but then there was bit of a roller coaster as the MUF rose and dropped as the K-index fluctuated. In amongst this there was DX to be had with HK3C in Columbia and HP3SS in Panama romping in on 10 metres.

The daytime critical frequency was often above 7MHz, giving good inter-G contacts on 40 metres, although it often dropped back down, leaving the band only open to Europe.

Next week it currently looks like the Sun is going to be more settled with no sign of coronal hole activity, at least in the first half of the week. There are currently two small sunspots visible on the solar surface and the prediction is the solar flux index will be in the high 70s or low to mid-80s.

If our prediction about the coronal holes is correct there should be settled HF ionospheric conditions for most of the week, with maximum usable frequencies at their seasonal norms. This means we could see openings up to and including 28MHz, although 14-24MHz may be more reliable. The lower bands should also offer some good DX with 40m and 80m coming into their own after dark. Hopefully this will be good news for the CQ World Wide SSB contest, which takes place this weekend, the 28th and 29th.

VHF and up

Moving into November often brings some settled high pressure weather and this year is no exception. There is likely to be a high pressure focus over southern UK from time to time for much of the week. So this is a good week to check your VHF station out and try some of those tropo paths, especially south towards the continent and across Biscay towards Spain, the Azores and Canaries.

There will be periods when the weather turns more unsettled with a cooler northerly, especially down the North Sea. Showers at this time of the year can be quite active as a cold northerly air flow crosses the relatively warm water of the North Sea, so raising the possibility of rain scatter on the GHz bands.

Moon declination goes positive again on Thursday and it is moving towards perigee a week today. Path losses will fall throughout the week so it’s time to start your EME activities again for another cycle.

Last week saw a few 50MHz sporadic E reports, so don’t give up completely on that mode, especially as we now have low-signal digital modes in our VHF DX tool bag.

There are no significant meteor showers this week, so focus on the early mornings around dawn for the best chance of QSOs via random meteor scatter.

Category: GB2RS Propagation News