Propagation News – 26 April 2015

Last week we said that the NOAA prediction was for a solar flux index of up to 135, but we thought this was pessimistic. We were proved right as the SFI soared to 154 on the 21st. However conditions remained very unsettled with the Kp index hitting four at times and with many M-class solar flares.

This week looks like it will be very similar with the predicted solar flux index around 135, but with continued unsettled geomagnetic conditions due to coronal mass ejections and high-speed solar wind streams.

On HF, this is a good month to look for long path openings to Australia. Peter, VK6APZ can often be heard around 0900-1000UTC around 18.120MHz, just before his sunset. This is at a time when there is no 20m opening and casual listeners could miss the opening on 17m. A similar opening to New Zealand can occur on 17m or 15m at around 0700UTC.

Propagation can vary dramatically, even on adjacent bands, and it is worth playing with a prediction tool like VOACAP Online to see where paths might exist.

VHF and up propagation news

This week starts with low pressure back on the charts and unsettled weather over the country for much of the week. This will mean a return to mainly flat tropo conditions until midweek. Towards the end of the week a new high will drift east and may provide some limited tropo enhancement as it reaches the UK by Friday.

There will probably be some large showers and thunderstorms in the first half of the week, so rain scatter will be a possibility; a good hint is to follow the more intense echoes from the various rainfall radars on the web.

The Es season has already produced some limited activity on 10m and 6m and should only grow in coming weeks. In view of the potential for jet streams to contribute to the locational properties of Es, this next week offers some good jet stream potential, suitable for Es paths into Europe and Scandinavia.

After last week’s Lyrids meteor shower it’s back to random meteors, the early morning being the best time.

Moon declination is falling and moving away this coming week, meaning increasing losses for EME. But moon windows are still long in the UK.

Category: GB2RS Propagation News