HF News
Last weekend saw the Kp index soar to seven, with a massive visible aurora over the UK. Unfortunately, many of the UK’s leading DXers and VHF enthusiasts were at the RSGB Convention in Milton Keynes, so missed it!
The aurora was caused by a very strong solar wind, emanating from a coronal mass ejection on the Sun, which occurred the previous Thursday.
The solar wind speed hit 750-850 km/s and the Bz component of the interplanetary magnetic field (IMF) shifted sharply south at times, meaning it coupled with the Earth’s magnetic field more easily.
This has now settled, and we are back to a more reasonable Kp=1 to 3. The solar flux index has also been relatively high, often in the 130s, with only minor C-class solar flares. This has meant the MUF over a 3,000km path has reached more than 28MHz at times, although 21MHz has been more reliable.
Better autumnal HF conditions are returning, with the 1.3kW KQ2H FM repeater in the Catskill Mountains, New York State, faintly audible at times on 29.620MHz some afternoons. Conditions should improve over the coming weeks.
DX to be worked on HF next week includes JD1BQP (Ogasawara), TZ4AM (Mali), 6O2M (Somalia), V63SC (Micronesia), 9N7XT (Nepal), 3DA0GY (Eswatini), S9R (Sao Tome and Principe), and C5R (The Gambia).
Next week, the Space Weather Prediction Centre forecasts that the solar flux index should remain around the 100 mark. Geomagnetic conditions should be settled for the first half of the week, but then become unsettled with a Kp index up to four on October 21-24.
There is a slight risk this weekend of unsettled geomagnetic conditions due to another large coronal hole on the Sun’s surface, which becomes geoeffective late Friday the 16th.
VHF and up
The unsettled weather pattern will continue through the whole of the coming week. This does mean that there will continue to be periods of wet and windy weather, but the other side of the coin is that it will alternate with more settled spells of weather.
Limited periods of Tropo are possible, although probably somewhat restrained due to the transient nature of the Highs. However, in the unsettled periods the locally heavy frontal rain and heavy showers will be good candidates for some rain scatter. The strong winds in such cases may make tracking the echoes for GHz QSOs a challenge.
The meteor scatter prospects are reasonable this month and the next meteor shower of note is the Orionids, which peak on 21st into the 22nd and are the result of the Earth’s orbit passing through the debris from Halley’s Comet.
The prospects for aurora have been worth considering in recent weeks, typical of the autumn season, and there’s good reason to keep monitoring the Kp index for signs of it going above Kp=5. Bear in mind that auroral events may be short-lasting and often found in the early evening, so don’t leave it until later before going outside for a look.
EME now, and Moon declination is at its lowest but starting to rise again. We are still a week away from positive values. Moon windows lengthen and peak Moon elevation is rising. Apogee was Friday the 16th, so path losses are falling again. 144 MHz sky noise is high until Monday, then low for the rest of the week.