Propagation News – 12 July 2026

Compiled by G0KYA, G3YLA and G4BAO on 9 July, 2026.

We have had another week of mixed HF propagation.

We started with a Kp index of 6.33 on Saturday, 4 July which was caused by a coronal mass ejection (CME). This caused a strong G3 geomagnetic storm and auroral conditions.

A check on the bands on 4 July showed poor HF propagation with lower maximum useable frequencies (MUF), and weak and watery signals from the NCDXF beacons on 14.100MHz.

But conditions have since improved and we had a Kp index of less than 3 over the past few days, which means the ionosphere has returned to normal.

Meanwhile, the solar flux index declined from a high of 203 on Thursday, 2 July to a low of 116 on Wednesday, 8 July. That’s quite a change and means that HF propagation has declined somewhat.

An Earth-facing coronal hole has now passed with few effects and currently there is nothing of significance rotating into view.

Solar flare activity has also declined with only two M-class flares over the past three days.

The big question is: what happens next?

Active region 4482 on the Sun continues to be a major threat. A solar flare and accompanying CME could soon ruin our chances of good HF conditions. The declining solar flux index hasn’t helped either.

Again, NOAA predicts the solar flux index will be in the 120 to 145 range over the coming week with a Kp index of 2 to 3. So, good news overall.

DX to be worked this week includes D73G on Ch’ongsan Island; T22TT from Tuvalu; TY5FR in Benin; RT9K, the Arctic Legends IOTA DXpedition; JK1HFB/JD1 in Ogasawara; OX3LX from Greenland; VP5G operating from Turks and Caicos.

VHF and up propagation news

Compiled by G3YLA and G4BAO

The weather is becoming a talking point in terms of the heatwave developing over much of the country, especially in the south.

This has propagation implications too. It’s all being driven by a large area of high pressure, which for much of the coming week resides to the north and west of the British Isles.

This will give a northeasterly breeze over the southeastern half of the UK, which means it will be blowing in from the North Sea, possibly with areas of low cloud at times.

The propagation implication is that this represents almost ideal tropo potential.

This is especially the case when the low cloud moves inland and we find a marked contrast between the hot dry air above the inversion and the cool, moist and shallow cloud layer below.

However, in high summer the daytime heating over the land degrades the lift during the morning as the temperature inversion is broken down by the strong sunshine.

Northern areas will see the occasional weakening front clip the northwestern fringes of the UK to offer up the only rain scatter prospects available at first.

However, some models are starting to suggest a breakdown by the end of the week, so more rain scatter and an end to the tropo.

The prospects for aurora depend upon the Kp index, which at the moment is mostly cycling between 1 and 3. This is not anything to generate radio interest, for which a Kp index of 7 is nearer the mark.

Meteor showers are still in the random state with the next shower, the Delta Aquarids, coming late in the month.

The Sporadic-E season is doing well this year, particularly for digital modes. There have also been events for CW and SSB up to 2m at times. However, not all parts of the country experience an opening, so watch the clusters for early notice of workable paths.

EME now, and declination reaches maximum today, 12 July, so Moon window lengths will peak along with maximum Moon elevation. Path losses are still falling, until perigee tomorrow,13 July.

144MHz sky noise is moderate until Tuesday, 14 July when the Sun and Moon are close in the sky, then low for the rest of the week.

Category: GB2RS Propagation News