Propagation News – 11 April 2021

| April 9, 2021

We had yet another week with poor sunspot numbers. Although we started the week with a sunspot number of 11, representing one spot in one group, it didn’t take long for this to decline and we were back to zero spots again and a solar flux index of 76.

What we did have, however, were the effects of a high-speed stream from a coronal hole, which sent the Kp index up to five during the afternoon of Wednesday the seventh. This was relatively short-lived though and the Kp index was back to one by Thursday morning.

A pre-auroral event enhancement saw MUFs climb above 21MHz on Wednesday, which saw some DX being worked via FT8 on 15 metres.

Otherwise, the DX attention has been on the Russian C92RU DXpedition to Mozambique. This has been worked by UK amateurs on all bands from 160m to 15m and the propagation prediction engine at shows that your best chance of working them is from 1600 to 1800UTC on 30 metres, 20 metres and 17 metres. They have also been worked on the low bands in the late evening and early hours. They are currently due to dismantle their station on Tuesday the 13th of April so don’t delay if you want C92 in the log.

Next week NOAA predicts the solar flux index will remain around 70-72, with a maximum Kp index of two. As of Thursday, there were no obvious coronal holes rotating into view, which bodes well for HF propagation over the next few days. Let’s hope it continues until the end of next week.

VHF and up

This weekend we start the period with a wintry theme to the weather, especially in the north, and a longer period of rain sleet or snow over the Downs in the south. This means it’s a rain scatter story for the GHz bands again. The models diverge after midweek, when one evolution brings an area of high pressure in from the west, while others stick with the unsettled showery theme. This means that the coming week is largely a rain scatter option, with an outside chance of a new high in the second half of the week for a hint of Tropo.

The maps show no tropo over the UK until this coming Friday, when conditions look promising over the sea path from the North of Scotland up to the Faroe Islands.

As mentioned last week we are getting closer to the next Sporadic-E season, so as usual the message is to check 10m and 6m for signs of activity, especially on the digital modes.

Moon declination is positive again so peak Moon elevations and visibility windows will increase as the week progresses. The Moon reaches apogee on Wednesday so path losses will begin to fall from then.

We are slowly coming out of the annual meteor activity minimum, with the April Lyrids starting to ramp up to their peak on the 22nd. Already there are signs of more meteor reflections being reported.

Category: GB2RS Propagation News