Propagation News – 27 September 2015

Starting on a happier note, it has been good to see the HF bands becoming more active this week as we head into autumn. With a solar flux index of around 105, fifteen metres has been showing promise with the YV5B beacon in Venezula and 4U1UN beacon in New York romping in on 21.150MHz during mid to late afternoon. These are both part of the worldwide International Beacon Project that lets you get a feel for global conditions on the five highest HF bands.

The “Six Gs” DXpedition to Niue Island in the Pacific has also proved to be fruitful for better-equipped stations. They have been worked on a variety of bands with 20m, 17m and 15m being productive.

Conditions have still been variable with the Kp-index hitting seven last Sunday due to an incoming coronal mass ejection hitting the earth. But the middle of the week was more settled, which no doubt helped the higher bands.

This coming week, the solar flux index is predicted to be in the range 90-100. Geomagnetic conditions may be reasonably settled, at least until next Thursday and Friday.

As always, solar flares, coronal mass ejections and high-speed solar wind streams may cause disrupted conditions at times.

VHF and up propagation news

The area of high pressure over the country this weekend will continue to be a major player on the weather charts throughout the coming week. Most weather models start off with the centre over the North Sea, then one evolution transfers it to the west of Ireland, while another to the north of Scotland. This means that the early part of this week should be good for enhanced VHF/UHF tropo conditions on paths within and from the UK. Paths will occur where the temperature inversion is strongest and the moisture content near the surface greatest.

Get those horizontal beams turning and try SSB and CW modes to get the best out of any lift conditions. Look for areas of fog or misty low cloud on the satellite pictures to get the best paths.

Note that it is often better to try paths along the side of the high rather than across its centre, since the temperature inversion can be too low in the middle.

Again, no major meteor showers this week so keep looking in the early mornings for the best random meteor scatter opportunities.

For EME operators, the moon’s declination goes positive today with increasing Moon windows starting in the evening until the following morning. Monday sees the moon at perigee, which means lowest losses.

Category: GB2RS Propagation News