venerdì 6 maggio 2022

Propagation News – 8 May 2022

GB2RS News Team | May 6, 2022

Last week was characterised by solar flares. At the time of writing, we have seen more than 50 since the 1st of May, including one high-energy X-class flare. This occurred on the 3rd of May at 1325 hours and caused a radio blackout over much of the Atlantic. Luckily, the Kp index has remained low, which has enabled the ionosphere to develop. And solar flux indices have been steadily climbing and reached 130 by Thursday.

There have been many reports of good propagation. It has been a simple case of being in the right place at the right time. Ten metres has been open well into the evening at times, as well as providing paths to Australasia in the morning. At other times people have reported the band as being dead.

We have also seen the beginnings of the Sporadic-E season with reports that 10 metres has been wide open to Europe at times. Hopefully, this will develop as the month goes on.

Next week, NOAA predicts that the SFI may dip before climbing back into the 120s. However, the US Air Force says that it will just continue to rise, perhaps hitting 140. This seems more plausible going on past performance.

Geomagnetic conditions are predicted to be quiet with a Kp index of two. However, it would only take one Earth-facing coronal mass ejection to spoil this entirely.

VHF and up:

Starting with Tropo news, this weekend sees the new week starting with high pressure right over the British Isles. This high will drift slowly southeast into the continent by midweek, centred over the Balkans. There should be some reasonable Tropo paths, especially to the south into France and northern Spain. This will be fairly short-lived because, starting midweek, a weakening cold front brings rain to northwest Britain and breaks up into showers as it moves south.

This brings the prospect of some rain scatter for a while and as per last week, this is likely to peak in the afternoon. After these showery days, another high appears by Friday to end the week, gradually transferring to the North Sea with a further chance of Tropo. Bear in mind that these weather forecasts are 10 days out so there are bound to be differences in the models. From midweek, some models retain the showery risk for longer.

Summer Sporadic-E, or Es, propagation is well under way with some early reports up to 2m by Chris, G0DWV who heard an IV3 briefly on 2m before dropping back into the noise. We have had many hints of the new season, mostly on 10m and 6m.

Just to remind you that Es activity tends to come in two periods, mid-morning and again late afternoon/early evening. Remember the daily blog on, which gives the current day’s prospects as well as an EPI (Es Probability Index) map to allow you to plan your shack activity.

The Eta Aquariid meteor shower is tailing off now but the Make More Miles on VHF website suggests that meteoroids released from the minor planet 2006GY2 may cause activity on the 15th of May around 1020UTC. Apparently, the stream should be dense, so worth a look.

The Moon has passed peak declination and we are a week away from next Sunday’s perigee. The week’s trend will therefore be for shorter Moon windows and peak elevation and falling path losses. 144MHz sky noise is low this week, slowly rising and reaching 400K next Sunday. (