Propagation News – 21 July 2019

| July 19, 2019

There is very little to say about HF propagation last week. Conditions were relatively settled, thanks to a respite from solar coronal hole activity, but the HF summer doldrums are still taking their toll. The summer ionosphere is composed mainly of diatomic gases rather than monatomic, and these are harder to ionise. This means maximum useable frequencies are lower during the summer daytime than they are in winter. However, night-time MUFs tend to be higher, with perhaps 14MHz remaining open much later into the evening in summer.

The good news was that station 1A0C, The Order of Malta’s Italian Relief Corps, was active on HF, which gave DX chasers something to aim for. Sporadic E was the main mode of propagation to the station, which confusingly, is based in Rome and not Malta. And the result was that many hams were able to put 1A0C in their log on many band slots.

NOAA predicts more of the same next week with the solar flux index around 67 and the K-index at two, thanks to a quiet Sun. However, a week is a long time in terms of HF propagation, so there is always the chance we may get a solar coronal hole rotating into view later in the week.

Meanwhile, make the most of the sporadic E season, which is now less active than it was. Es can bring forth propagation on all the HF bands, not just 28MHz, so keep looking and call CQ—you might get a surprise.

VHF and up

Mixed weather at the end of last week, with some weather fronts crossing the country, brought patchy rain and some rain scatter. Thereafter, pressure probably remains low to the north and west of Britain, while a weak ridge remains close to south-east Britain with a chance of tropo, especially across the North Sea and English Channel. By mid-week the pressure pattern has weakened and after some very warm weather, there is a trend for thundery showers to develop—once again good conditions for rain scatter.

Sporadic E continues to show a presence as we move to the latter stages of the season. However, the jet stream pattern looks less active over Europe, although the Atlantic domain offers some activity as the jet stream buckles to provides options for paths to the United States.

Moon declination goes positive on Tuesday and we are past apogee now, so EME conditions will improve throughout the week with lengthening Moon windows, lower losses and increased moon elevation.

Again there are no major meteor showers this week, but the Piscis Austrinids on the 28th is a small one and just above the horizon in the UK, so continue to look for best DX opportunities via random meteors around dawn.

Category: GB2RS Propagation News