HF News
There has been plenty to work on HF this past week. 3Y0K on Bouvet Island is still attracting a lot of radio amateurs, but there is also 8Q7ZW on the Maldives and German group J51A on Guinea-Bissau to get your attention.
DXpeditions to look out for next week include TX5EU Austral Islands, YJ1JXZ Vanuatu, and the tail-end of operations at T80K Palau and VP2EAD, VP2ELX and VP2EWE on Anguilla.
HF propagation has been reasonable rather than outstanding with a solar flux index in the 140s, declining to 120s as the week progressed. There have been a few C-class solar flares, but nothing stronger.
Geomagnetic conditions have also been reasonable with the Kp index mostly in the twos and threes. There was one excursion where the planetary Kp index hit four around March 7th and 8th, but otherwise it has been relatively calm.
The MUF over a 3,000km path has been exceeding 28MHz on most days and 14MHz was open to the Maldives via FT8 as late as 2200hrs UTC on Tuesday the 10th.
Next week, the standout item is a large, but relatively thin, coronal hole on the Sun, and the high-speed solar wind stream from this is expected to reach Earth beginning March 13th and across this weekend. Expect the Kp index to rise and HF propagation, especially on northerly paths, to suffer.
The Space Weather Prediction Centre forecasts that the SFI will decline further to be around 110 next week. After this weekend’s geomagnetic disturbance, due to the coronal hole, the Kp index is forecast to be more settled with a predicted maximum Kp of three. Things may hot up later in the week with a predicted Kp of four, rising to six on March 21st. Expect reduced maximum usable frequencies and poorer HF propagation, particularly on polar paths.
VHF and up
The current spell of changeable weather is likely to stay with us through the bulk of next week, but there is a glimmer of hope for better conditions after mid-week with a suggestion of high pressure over northern Britain.
To begin with this means that rain scatter (including snow in places) will be worth checking out on the GHz bands, but strong winds may test antennas at times. The transition to high pressure should lift conditions a little, but since it’s forming in a cold polar air mass, it may not be as good as it could be.
As it looks now, next Tuesday’s 1.3GHz UKAC on March 17th is still in the wet and windy period, so maybe a rainscatter bonus if the rain is heavy enough to affect such a low GHz band. Aircraft scatter will always be the best option for this band when tropo is poor. The 70MHz UKAC on Thursday 19th may fare better for Tropo in GM and GI.
Meteor scatter will offer up just meagre rations as we remain in between major showers – the April Lyrids are still a long way away. Aurora is still in the frame around the spring equinox, so as usual check for the Kp index moving up to Kp=5 or higher.
Sporadic-E is not usually part of the story at this time of the year in these latitudes and, if anything does get triggered, then look to explore the path on digital modes first to see which directions are being favoured.
For EME, a poor week upcoming with Moon declination negative but rising, not going positive until next Thursday. We continue with short Moon windows and low peak elevation but with falling path losses. While 144 MHz sky noise is moderate to low in the coming week, Wednesday and Thursday see the Sun and Moon close in the sky, meaning high noise on the lower bands due to wider antenna beamwidths.