Compiled by G0KYA, G3YLA and G4BAO on 30 April. Last week was about as good as it gets at this point in the solar cycle. We had a solar flux index in the 140s and a Kp index that was pretty flat, often below 2. That’s good news for HF as it means the ionosphere […]

Compiled by G0KYA, G3YLA and G4BAO on 23 April, 2026 Last week’s HF propagation was dominated by the effects of a high-speed stream from a large coronal hole on the Sun. This pushed the Kp index up to 4 and 5 at times with the result that maximum usable frequencies, or MUFs, were lowered. The […]

Compiled by G0KYA, G3YLA and G4BAO on 16 April, 2026 Last week was characterised by a low Kp index and an equally low solar flux index. The Kp index was predominately below 2 all week thanks to a lack of Earth-directed CMEs, or coronal holes. Unfortunately, that is about to change. The solar index has […]

Compiled by G0KYA, G3YLA and G4BAO on 9 April, 2026. After a pretty stormy run-up to Easter, from a geomagnetic disturbance point of view, the Sun has been quieter. In fact, the Kp index has been below 3 all week. Unfortunately, the solar flux index has also declined, standing at 108 on Thursday, 9 April. The […]