HF News
As we head into September, Autumnal HF conditions are fast approaching. We can expect the MUF to climb during the day and DX to become more plentiful.
However, we are not there yet, so it may take a few more weeks before we really see much of a change in HF propagation.
Meanwhile, solar activity remains quite low, with a solar flux index around 100-110. Geomagnetic disturbances are still occurring, but their effects have been minimal. The Kp index rose to five on the eighth due to the effects of a coronal hole stream. Luckily, this was short-lived and the following day the Kp index was back to being in the range of 2-3.
The last four days have seen only minor C-class flares, but with seven sunspot groups visible the risk of solar flares and associated CME activity remains quite high.
MUFs over a 3,000km path have reached 24.9MHz at times, although 17 and 15 metres have been more usable. Expect the daytime MUF to climb to perhaps 28-29MHz by the end of the month.
Two coronal holes appear to be developing on the Sun and will become Earth-facing around the 12th and 13th, so there could be a coronal high speed stream hitting us around the 14th to 16th.
DX to be worked next week includes RI1FJZ (Franz Josef Land), not be confused with RI1FJL, which has now ended), V47YA and V47RCX (St Kitts and Nevis), KH8WW (American Samoa), S79/DL2SBY (Seychelles). Also, look for PJ2/K5SL (Curaçao) from the 18th and 8Q7JH (Maldives) from the 20th.
Next week the Space Weather Prediction Centre forecasts that the SFI may remain in the range 105-115. We may expect unsettled geomagnetic conditions from the 14th to the 16th, possibly due to the coronal hole activity mentioned earlier, with a predicted Kp of four, but otherwise the rest of the week may remain calm with a Kp of 2-3.
VHF and up
The current spell of changeable autumnal weather looks likely to remain with us for most of the period, but the UK covers a broad span south to north and some differences will show up.
Firstly, despite the arrival of some fronts with rain in the south, they will probably be weaker than in northern Britain and with only occasional patches of rain. For the rest of the time look out for weak ridges of high pressure and periods of Tropo into the near continent and possibly south across Biscay to Spain.
For the northern half of the country the weather systems will be more active and Tropo less likely, but you could find some occasional rain scatter opportunities on the GHz bands.
Meteor scatter options are still in the control of random activity with no major showers playing a role.
The aurora prospects are probably not zero, but recently alerts have been for minor levels of disturbance with a Kp up to Kp=5, but nothing dramatic on the radio aurora front. Being autumn it is always worth monitoring, since it’s a good time of the year for aurora if the triggering solar activity is sufficiently strong as we head towards the Autumnal equinox on the 23rd.
EME now, and Moon declination continues to fall until its lowest point around September 18th. Meanwhile, path losses continue to rise until apogee, the Moon’s furthest point from Earth, also on the 18th. Sky noise remains low and then rises again around the 18th and the 19th, when the Moon is in Sagittarius.