RSGB
GB2RS News Team | May 30, 2025
Last week’s high-speed solar wind, from a massive coronal hole on the Sun, took its toll on the HF bands. However, this week has been little better. Another coronal hole running diagonally across the Sun has been emitting particles that have pushed the Kp index up to a maximum of 6.67 which puts us into visible aurora territory.
Nevertheless, some DX has been worked including CP4BT in Bolivia, ZP5KP in Paraguay and V44KAI St Kitts and Nevis. These were reported by Karl, G0SKW on the CDXC Slack alerting system.
BA100IARU, a special event station celebrating the 100th anniversary of the International Amateur Radio Union, has been active from Beijing, China and has been worked on 20m CW. The station’s QRZ.com page provides real-time updates on which band the operators are working on.
Most of the DX has been worked on 21, 18 and 14MHz with the 10m band mostly closed due to the summer doldrums. There have not been too many Sporadic-E openings on the 10m band. Instead, most of the Sporadic-E reports have been on the 6m band.
The solar flux index has increased, standing at 144 on Thursday 29 May, which is always a good sign. In fact, the solar disk is looking quite healthy at the moment with spots in both hemispheres.
As of last Thursday, the 29 May, there had been 43 C-class flares over the previous five days, as well as six more potent M-class events and one X-class flare. So, the Sun is still very active.
Next week, NOAA predicts that the solar flux index will reduce again, perhaps going as low as 110 by Wednesday 4 June. It does look like we are in for a rough ride with unsettled geomagnetic conditions forecast for the coming week. Looking further ahead, the 13 and 14 June seem to be the worst days, when a Kp index of five is forecast.
As usual, a high Kp index can result in lowered maximum useable frequencies and aurora-like conditions, with a slow recovery.
VHF and up:
The weather continues to be unsettled into the coming week, especially for northern areas, but with some drier and warmer spells in the south.
There does not appear to be strong signs for any Tropo success, but there should be a chance of occasional rain scatter on the GHz bands.
Some models suggest we are on the edge of high pressure over the North Sea. Others drive a deep low right across the country. This will resolve itself next week, but for now it’s not at all clear which forecast will win through.
The prospects for meteor scatter are mostly random meteors but towards the end of this week the daytime Arietids will peak to enhance chances further.
The solar auroral alerts keep coming, so it’s reasonable to expect the chance of some radio response such as watery-sounding signals on HF, even if we don’t go to the full effects on VHF. It’s certainly worth watching for those increasing Kp values.
The Sporadic-E prospects often burst into life about now. So, after a few reasonable 6m band openings, like the one into southeast Europe on Wednesday 28 May, make sure you are ready for the first week in June – one of the prime weeks for Sporadic-E opportunities.
This is partly due to meteor input and the fact that the tidal winds in the E region are taking on their summer pattern. The long polar days mean that the low-pressure weather patterns are also beginning to affect the northern polar routes to China and Japan across northern Russia with their possible weather triggers, like jet streams.
EME path losses are increasing again. Moon windows shorten, and peak elevation is falling as the Moon declination goes negative again on Wednesday the 4 June. 144MHz sky noise is low and remains low as the week progresses.
(Mike Terry/BDXC)
