GB2RS Propagation News
Propagation News – 27 April 2025
We had yet another week of unsettled geomagnetic conditions. The Kp index peaked at 5.33 on the 21 April as the solar wind speed hit just above 600 kilometres per second, and active geomagnetic conditions were observed. This was caused by a massive coronal hole on the Sun’s surface, which measures nearly 700,000km in length. […]
Propagation News – 20 April 2025
Last week was characterised by increased Kp index numbers and severe geomagnetic storms, peaking at G4. These drove down maximum usable frequencies and disrupted DX contacts, especially on the higher HF bands. The solar wind speed increased from 380 kilometres per second to around 500 kilometres per second on 15 April and an increase in […]
Propagation News – 13 April 2025
A fast solar wind caused some disruption last week, often sending the Kp index up to five, with many three-hour periods in excess of four. The solar wind speed was in the 600-700 kilometres per second range, which caused a moderate, G2, geomagnetic storm and visible aurora at higher latitudes mid-week. Glancing CMEs that left […]
Propagation News – 6 April 2025
We had a week of mixed solar conditions, but it ended with an SFI of 182 and a Kp of 3.67 on Thursday 3 April. The geomagnetic field declined to quieter levels following a prolonged period of active, Kp4 conditions earlier on Wednesday due to solar wind enhancements. This impacted propagation, with the critical frequency […]
Propagation News – 30 March 2025
Last week’s space weather was dominated by a large coronal hole on the Sun. This was probably one of the largest we have seen for many years. Moderate, G2, geomagnetic storming was observed following the arrival of a solar wind stream from the hole, with the wind speed exceeding 600 km/s on Wednesday 26 March. […]
Propagation News – 23 March 2025
Last week was pretty unremarkable from an HF perspective. After the disturbed geomagnetic conditions on the 12 to the 14 when the Kp index rose to five, conditions were a little more settled. The solar flux index hit 204 on the 17 March but then declined back to the 180s. Having said that things were […]
