venerdì 30 novembre 2018

Propagation News – 2 December 2018

The CQ Worldwide CW contest last weekend showed that you can work DX with zero sunspots. Reports show that stations as far west as Arizona and California, plus the Caribbean, were workable from the UK on 20 metres, plus there were reports of some limited F2-layer openings on 10 metres. Chris, G0DWV even reported an afternoon greyline opening to Japan on 80m using a four-square antenna array for the band.
The sun remained spotless last week and geomagnetic conditions were very settled, which no doubt helped the HF DX. The Kp index never rose above two and was often at zero for long periods. However, at the time this report was being prepared there was still an alert out for potentially-unsettled conditions on Friday, the 30th, and across the weekend due to ongoing coronal hole activity.

NOAA predicts that next week will see the solar flux index pegged at 68 again. Conditions should be a little more settled geomagnetically with a maximum K-index of three for most of the week. Conditions may be a little worse on Friday, the 7th, and Saturday, the 8th, due to a high-speed solar wind stream from a recurrent coronal hole that will become Earth-facing again.

This is a good time to start to think about the lower bands. Eighty and 160 metres are starting to come into their own with the longer nights. If you have never worked the USA on 80m then it might be worth looking around UK sunrise. There is often transatlantic SSB activity around the top of the band, especially 3790-3800kHz, in the early morning.

VHF and up:
There is a distinctly unsettled look to the charts again for the next week. This means that tropo will not be a big player and the only weather-related DX option is probably limited to some occasional rain scatter on the microwave bands. During the winter months, rain scatter is most likely around the coasts than inland. Last Tuesday’s SHF UK Activity Contest saw the west of the UK missing out as the rain moved east just before the contest started, leaving a disturbed troposphere in its wake. This highlights the fact that good propagation rarely waits for you if you only operate during contests. Rain scatter paths from East Anglia to the north remained good throughout.

Other options might include some aurora on VHF if we are lucky. ‘Space Weather Woman’ Doctor Tamitha Skov tweeted last week that we might reach solar storm levels at the beginning of December due to the coming fast solar wind. So be on the lookout for that.

There are three small meteor showers this week—see the Make More Miles on VHF for details—and remember that the big Geminids shower is only two weeks away now.

Moon declination goes negative today, so Moon windows will be shorter and of lower elevation as the week progresses. Note that the Sun will be very close to the Moon on Friday.