HF News
Things have been quiet on the solar front, but is that all about to change?
The solar flux index has been sitting around the low 120s for a few days and the geomagnetic Kp index has been below two.
Other than a couple of M-class solar flares. Activity has been quite quiet. One of the flares was the source of a faint, easterly-directed CME with no Earth-directed component.
But, there are a number of solar features that could change all that. Firstly, a coronal hole on the Sun’s surface will become geoeffective on Wednesday 24th, meaning a solar wind stream could impact the Earth around the 25th-26th.
Expect the Kp index to rise as a result, perhaps to four, and MUFs to drop. This shouldn’t last too long and by the weekend it should have cleared.
Meanwhile, a large sunspot group is due to appear from around the Sun’s eastern limb. The cluster as observed by the ESA solar orbiter spacecraft shows arch-like structures known as coronal loops seen towering over the east limb.
Quite what this will do for HF propagation is hard to say, but keep an eye on solarham.com for updates.
DX to be worked next week includes FP/KV1J (St Pierre and Miquelon), JD1BQP (Ogasawara), 5H3DX (Tanzania), CN2NQV (Morocco), FO/F6BCW (French Polynesia), and PJ2/PH2M (Curacao).
HF conditions have been relatively poor with many stations complaining that there is not much activity. A quick check revealed little action on 21MHz and higher, other than Sporadic E openings. So it looks like 14 and 18MHz are the main DX bands at the moment.
Next week NOAA predicts that the SFI may increase to 145 by July 1st. Once we get over the effects of the coronal hole’s high-speed solar wind stream the Kp index is predicted to go back down to two.
VHF and up
The typical high summer patterns of jet streams take a step back in mid summer, but any that do crop up, and there should be some in the unsettled weather, can give plenty of value for Sporadic E since the ionosphere is well primed by meteor debris from the June Bootids.
Multi-hop Sporadic E paths to the U.S. and Far East are likely to be a surprise at times, often short lasting for individual stations, but overall it is a good time of the season to be optimistic.
It can be a challenge at this time of year since tropo is also a strong player due to the hot air from the land moving out across the cooler sea water around the UK.
This provides ideal duct conditions that persist over the waters throughout the day, but may struggle for stations well inland. It can also cause confusion as to whether you are working Es or tropo on occasions, but if it is tropo it will be much longer lasting and particularly good overnight on the high bands …. if the path works on 70cms it is probably tropo.
Meteor scatter is best around the random period maximum, which is just around dawn. Rain scatter is a good option – watch for lightning activity as a clue for intense precipitation. If you are fed up with all that, the long shot option might be aurora, but that is relatively rare in high summer and not visible easily.
EME now and path losses are high as the Moon is near apogee – its furthest point from Earth. Declination is also at a minimum. Sky noise is also high, but will improve as the week goes on.