Propagation News – 21 February 2016

This week has been a mixed bag in terms of HF performance. At times 10 metres has been open, with the 7P8C DXpedition to Lesotho putting in an appearance on the band for hours on Monday and Tuesday. But the high-speed solar wind is never far away and played havoc with geomagnetic conditions later on Tuesday and all day Wednesday, with the Kp index hitting six on both days. The solar wind exceeded 600 kilometres per second at times, causing geomagnetic storming at higher latitudes. This was due to an ongoing coronal hole on the southern hemisphere of the sun—a region within the sun’s corona with open magnetic field lines that allows a stream of particles to escape. This left the HF bands very noisy indeed.

Next week NOAA predicts the solar flux index will be in the range 100-115, which could spell openings up to 10m. The good news is that the K index is predicted to be a reasonably-settled 2 all week long. If this turns out to be accurate we can expect some good DX openings on HF.

Finally, don’t forget the lower bands. There have been some good openings to Australia and Asia reported on 80m during the hours of darkness, especially around greyline times.

VHF and up propagation news

There is another rather poor tropo week coming up, but with one possible glimmer of hope in the south around mid-week. We start the week with low pressure to the north of Britain and the long-term area of high pressure near the Azores. This makes for a cold start to the week with northwesterly winds and some snow showers possible, producing good highly reflective clouds for GHz band scatter modes.

Around mid-week, a ridge from the Azores high will cross southern Britain to give a brief enhancement, but nothing dramatic. It’s unlikely to last because low pressure will return by the end of the week.

Watch out for auroral propagation on the lower VHF bands in the coming week as the sun has been active and produced recent auroral propagation for northerly stations.

The seasonally-low random meteor rates continue and no major showers, so early morning continues to be best time day for random meteor scatter operation.

The Moon will be up overnight and in the early morning this week and its declination is decreasing. Moon windows will shorten and losses reach a maximum as the Moon reaches apogee, its furthest distance away, on Saturday.

Category: GB2RS Propagation News