Propagation News – 14 October 2018
Last week was not very good for HF propagation, with the effects of an enormous solar coronal hole, and its associated high-speed solar wind, sending the K-index soaring. There were, however, some upsides. The initial positive phase of a geomagnetic storm saw maximum useable frequencies rise to more than 21MHz during the afternoon and early evening of Sunday, 7 October. These positive phases are very hard to predict, but it is always worth checking, as a rise in the solar wind speed and pressure, coupled with a southward facing Bz or interplanetary magnetic field, can be signals that something is about to happen, often before the three-hourly K-index changes. The propagation charts at g0kya.blogspot.com include near real-time output from the ACE spacecraft, which can show these effects, or go to solarham.com where you’ll also find information.
HF conditions this weekend may be unsettled again. Another large equatorial coronal hole is moving across as the Sun rotates and became Earth-facing on Thursday. This means we may expect unsettled geomagnetic conditions from perhaps Saturday, the 13th. According to NOAA, conditions may again become unsettled on Thursday, the 18th, through to Saturday, the 20th.
Barring any surprises, we will likely see no sunspots this week, with the solar flux index hovering around 69. Unfortunately, this will probably remain the pattern for the next few months, although now we are into October we are seeing more DX available when conditions allow. Kenneth, TT8KO in Chad has been a strong CW signal on 15 metres at times, although the E6Y DXpedition on Niue in the South Pacific has proved a little more elusive for many.
VHF and up
This is going to be a much more autumnal week, with the best of the recent tropo having declined by now. That leaves us with predominantly low pressure near or just to the north of the British Isles and, at times, rather windy weather, especially in the north of the country.
Tropo will not be so likely next week, but there may be options for rain scatter perhaps, but we are not very convinced that this would be a major outcome.
I guess it’s a good time to check the antennas before the winter gales become the norm, and perhaps try your luck on the VHF/UHF frequencies in case of any short tropo or rain scatter events. Or why not make a winter resolution to learn Morse for the UHF and microwave bands, or perhaps set up your station for digital modes, where such QSOs can make use of bands that may be dead or marginal to voice modes.
The Moon is at minimum declination tomorrow and at apogee on Wednesday so it’s a poor week for EME, with short, low elevation passes and high losses.
October continues to produce meteor showers, with the Eta Geminids, a small one, peaking on Thursday followed by the Orionids a week this Sunday. But neither are much to get excited about due to low meteor rates.
Category: GB2RS Propagation News
