Propagation News – 14 August 2016

Last week the solar flux index climbed as NOAA had predicted, hitting 95 by Thursday evening. This was largely due to a new large crop of sunspots on the sun’s surface. These will rotate across the sun over the next few days and, as long as they don’t fade away, they should help the solar flux index remain high.

The week also saw some very unsettled geomagnetic conditions due to ongoing coronal hole activity, with the K index hitting three and four. Coronal holes are areas of the sun with lower energy and open magnetic fields that allow plasma to flow out. When these are in line with the earth the plasma can arrive in a couple of days.

NOAA predicts the solar flux index will remain in the range 90-95 over the next week, tailing off to 75 by next Sunday.

The beginning of next week may once again be subject to unsettled geomagnetic conditions due to coronal holes, with the K index predicted to hit four again.

HF is showing some signs of improvement with the Chilton ionosonde measuring the critical frequency as 5.875MHz at noon on Thursday. This means that we may see 18 and 21MHz opening to DX at times.

The prospects for VHF and UHF are looking pretty good for the start of the week with high pressure over Britain, later moving eastwards across the North Sea. This means there are likely to be some good opportunities for Tropo this weekend and into the first half of the week. Paths to the south across Biscay to Spain, Portugal and the Azores and Canaries look worth trying initially, and then along the east coast from East Anglia to Shetland early in the week.

The midweek period onwards looks more unsettled with the potential for some thunderstorms and perhaps rain scatter from the large cumulonimbus thunder clouds.

Sporadic-E has been good recently for some parts of the country, but it’s important to realise that it is very rare for all areas to have openings at the same time. The unsettled weather means that there should continue to be some jet stream activity, so check for late morning and late afternoon Sporadic-E.

The tail end of last week’s Perseids meteor shower should still give enhanced meteor scatter conditions for the next day or so.

The Moon is at minimum declination today, so short, but lengthening low-elevation Moon passes are the order of the day. These will lengthen and losses will reduce as the week progresses.

And that’s all for this week from the propagation team.

Category: GB2RS Propagation News