Propagation News – 21 March 2021

We had a week of settled geomagnetic conditions, following a mixed weekend. The consensus on the Commonwealth Contest was that conditions were not too good, although plenty of amateurs managed to put VK in their logs, despite the Kp index hitting four during the event. The Sun remained fairly quiet, with a solar flux index of 81 on Saturday and 78 on Sunday.

Otherwise, the DX interest has been focused on the Russian DXpedition A25RU to Botswana. They are there until the 26th of March and will be operating all modes, including CW, SSB and FT8. March is a good month for these North-South paths and Predtest.uk predictions show that 1600-1800UTC is probably the best time for a contact with Botswana on 30 to 17 metres.

Next week NOAA predicts the solar flux index will remain in the mid-80s, although this weekend is likely to see unsettled geomagnetic conditions again thanks to a high-speed solar wind emanating from an Earth-facing coronal hole. Expect maximum usable frequencies to decline, after the potential for pre-auroral enhancement as the plasma hits.

We expect to see the Kp index rise to four on Saturday and Sunday, although this will improve as the week goes on, bringing a more settled ionosphere and a predicted Kp index of two.

Meanwhile, ionospheric conditions remain subdued due to a lack of real sunspots. Spring remains a good time for North-South paths, and we also have the Sporadic-E season to look forward to in a couple of months.

VHF and up

The coming week is again suggesting that high pressure will feature on the weather charts for much of the period, at least in the south and east. This gives a possibility of further Tropo opportunities for most parts of the country, at least at first.

The trend thereafter is for Atlantic fronts to reach the west and north of Britain by mid-week, bringing unsettled weather conditions and putting an end to any Tropo there. But to compensate a little, it could introduce some rain scatter for the GHz bands.

There are always hopes that some out-of-season Sporadic-E could crop up, and there were weak 50MHz openings for digimodes last week, but ideally we need to be a bit further on into April before getting too excited.

Moon declination is at maximum on Monday, so peak Moon elevation gets to 62 degrees in the UK and the Moon is above the horizon for more than 16 hours. As we passed apogee in the middle of last week, path losses will continue to fall as the week progresses.

Meteor scatter enthusiasts will have to be content with the pre-dawn random meteor enhancement until the Lyrids meteor shower, which is still a month away.

Category: GB2RS Propagation News