U.K. Propagation Update

 

RSGB

GB2RS News Team | July 24, 2026

We said last week that there were no coronal holes to worry about. Yet two days later a massive crack appeared on the Sun, stretching over one million kilometres.

Luckily, this didn’t amount to much and it had little effect on HF propagation, but it does go to show that solar events can rapidly develop and that long-term forecasts can be tricky.

The solar flux index has increased over the past week, and was sitting at 150 as this report was being written. As we suggested earlier, geomagnetic conditions have been quiet with the Kp index generally below 3.5, which bodes well for HF.

Solar conditions have been good with only four M-class solar flares and no X-class events. Any coronal mass ejections, or CMEs, have been directed away from Earth.

We are still in the summer doldrums, so D-layer absorption remains high and maximum useable frequencies, or MUFs, are generally lower than in the autumn and winter. However, we have the IOTA contest this weekend, which is a great opportunity to work some far-flung DX. So why not dust off your radio and get on the air? With mainland Great Britain being an island, you might find you are in demand as EU-005!

Other DX to be worked this week includes RI0BW, the Arctic Legends IOTA DXpedition; 3B9HR from Rodrigues Island; PJ7/LA5IIA on St Maarten; TY5FR from Benin; E51CZZ and E51KEE on the Cook Islands; VU4R from the Andaman Islands; and VP5G operating from Turks and Caicos.

In the coming week, NOAA predicts that the solar flux index may fall back to 125 at first, and then down to around 108. Luckily, the Kp index is predicted to remain low, with a predicted Kp of 2, at least until the end of the month.

VHF and up:

There have been good examples of both tropo and Sporadic-E in the last week and there are reasons to continue with some optimism for the coming week.

This is still a good period for summer tropo. However, remember that hot days are the enemy of tropo over land, and it tends to be sea paths that survive throughout the day, whereas land stations have to make the best of nighttime operations.

That said, the main change in the weather pattern this coming week will be that the high pressure, which has been over the Atlantic just west of Britain, shifts into the continent and eventually out of reach by the end of next week.

So, the message is to get into the tropo while it’s here and use the latter part of the week for perhaps meteor scatter, with the Delta Aquarids peaking in the coming week. There is reserved optimism for this since it’s primarily a southern hemisphere event.

Rain scatter has been very hard to find recently but looks like making a comeback as the weather turns more unsettled with sequences of fronts crossing the country. Maybe only patchy weak fronts, but still worth considering.

The summer aurora prospects are staying on the marginal side, but watch out for Kp index values creeping above 5 before turning your beams north.

Sporadic-E, which is rolling along in main summer season fashion, has been very good lately and was producing a full set of bands, up to 2m, last Thursday 23 July.

As the weather turns a bit more unsettled, this could help with Sporadic-E. This could happen if the fronts move into the continent and weak jet streams, and possibly thundery cold fronts, create turbulence at the right sort of range over Europe. This will probably favour paths to Scandinavia and to the Balkans.

For EME operators, Moon declination reaches minimum today, 26 July, so Moon window lengths and peak Moon elevation are at their lowest value. 

With apogee yesterday, 25 July, path losses will decrease as the week progresses. 144MHz sky noise is high to start the week, peaking at over

2800 Kelvin today, 26 July, before slowly decreasing in the coming week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/07/24/propagation-news-26-july-2026/

Mike erry, UK/BDXC

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | May 8, 2026

Compiled by G0KYA, G3YLA and G4BAO on Thursday, 7 May 2026

We had another mixed week of HF propagation, with a Kp index of 6 one day and then three days later a Kp of less than 1.

The index hit 6.33 on the evening of Monday, 4 May, sparking aurora and poor HF conditions. But by Wednesday, 6 May it was back down to 0.67.

So, you can see why it is hard to predict what HF conditions are going to be like with ionospheric propagation being driven by the geomagnetic status rather than the solar flux index.

According to the CDXC Slack group, DX worked over the past week

included:

TZ4AM in Mali on 10m CW

T31TTT from Central Kiribati on 12m and 15m FT8 XQ6CF in Chile on 17m CW VP8A on the Falkland Islands on 60m CW 3B9G on 20m CW TL8BNW from Central African Republic on 40m SSB So, there is DX about if you hunt for it. Interestingly, all of the above, apart from T31TTT, were on southward paths, perhaps reflecting poorer conditions on polar paths at times due to the elevated Kp index.

Next week, NOAA predicts that the solar flux index will remain around

115 to 130 with calm geomagnetic conditions for the first half of the week.

However, unsettled geomagnetic conditions are forecast for 15-18 May with a possible Kp index of 5.

With five sunspot groups visible on the Sun’s surface and active region

4419 the source of two X-Flares on Friday, 24 April now about to turn back into Earth’s view, it is anyone’s guess what could happen next.

As we enter mid-May, we are getting closer to summer HF conditions. So Sporadic-E on the higher HF bands, lower maximum usable frequencies overall but perhaps 14MHz staying open all night are all features to watch out for.

Also look out for 10m band openings to Southern Africa around midday and paths to South America during early and late evening.

VHF and up propagation news from G3YLA and G4BAO:

The current period of weather seems to be a mix of weak high pressure and low pressure systems vying for dominance.

Therefore it implies that a mix of radio conditions will share our attention, with weak tropo from ridges of high pressure but no big highs on the chart while frontal rain bands or heavy showers bring a chance of rain scatter for GHz operators.

The prospects for meteor scatter may remain elevated for a while since we have only just passed the peak of the Eta Aquarids on Wednesday, 6 May. Remember the early morning hours tend to be best for meteor activity in general.

The aurora alerts have continued to provide a glimmer of hope but mostly for weak enhancements, so look for a Kp value of 5 or greater and signs of ‘watery’ sounding signals on the HF bands before turning the VHF beams to the north.

As we move into the early part of the Sporadic-E season, it will become the mode of choice for us during the next few months.

The general rule is to check for the two main periods of activity: in mid-morning and again late afternoon or early evening.

Listen for strong signals on the 10m band from Europe and then, as the event develops, the higher frequency bands will open up too.

In a strong event, the 2m band can even show up sounding like 20m. 

However, early season events tend to favour the 10 and 6m bands.

EME now. The Moon is past minimum declination and increasing, giving lengthening Moon windows and increasing peak elevation.

Path losses are decreasing now after apogee on Monday, 4 May. 144MHz sky temperature is low all week until Saturday, 16 May when the Sun and Moon are close in the sky.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/05/08/propagation-news-10-may-2026/

(Mike Terry, UK/BDXC)

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | April 24, 2026

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 ionosphere struggled and often the MUF over a 3,000km path was below 21MHz.

Yes, there were some openings up to 10m but they were generally weak. Checks showed that paths opened up to Brazil, Kenya and Chile on the 10m band using FT8, but the signals were well down in the noise and barely workable.

Get used to this as it could be the norm for the next few years!

Meanwhile, the solar flux index increased to 116 by Thursday, 16 April, no doubt aided by active sunspot group 4420.

Next week, NOAA forecasts that the solar flux index could rise to 125. It also predicts that the Kp index may remain low due to a lack of coronal hole activity. Fingers crossed that we don’t have any coronal mass ejections over the next week.

If this pans out as predicted, we could have some decent HF conditions over the next seven days. Yes, the MUFs may be lower, but 14, 18 and perhaps 21MHz could be usable, with very occasional openings on 24 and 28MHz.

DX to be worked this week includes TX9W from the Marquesas Islands; VP9KF in Bermuda; 7P8WR from Lesotho; C5B, C5C and C5D in The Gambia; D60DX in Comoros; and JD1BMH operating from Ogasawara.

VHF and up propagation news:

Compiled by G3YLA and G4BAO

The strong region of high pressure will remain with us for the next two weeks. So tropo should be considered a first-choice mode for a while.

The main criteria for the quality of any resulting tropo is moisture. This is because moisture is a component in the calculation of the refractive index of the air.

High pressure usually produces dry air above any temperature inversion but we may not always get the moisture below the inversion.

The end of last week was good with reports of beacons in Norway and Sweden into JO02 on 1.3GHz because of moisture present below the inversion.

However, if the dry easterly wind returns, it may not go so well.

Meteor scatter should continue to be uplifted by the declining Lyrids meteor stream, which peaked last week, and rain scatter is off the menu since the charts are dominated by high-pressure systems.

Aurora is showing as occasional weak alerts, but apart from the odd fluttery signals on the LF bands, nothing too interesting at the moment.

As usual, watch for the Kp index going up to 5.

Keeping the best until last, we are approaching the period when Sporadic-E usually becomes a mode of interest.

Work is well underway on a rewrite of the Propquest website, which should be ready soon. This will be the go-to place for the daily updates during the 2026 Sporadic-E season.

EME now, and the Moon is moving into a lower noise position. Declination is high but falling and path losses will increase as we move away from the Moon’s perigee, its closest point to Earth, which occurred on Friday, 17 April.

Apogee, the Moon’s furthest point from Earth and the point of highest path losses, occurs on Sunday, 17 May.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/04/24/propagation-news-26-april-2026/

(Mike Terry/BDXC)

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | April 10, 2026

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 only advantage has been a lack of solar flares. There have only been 12 minor C-class flares over the past three days compared with 29 C-class flares and six M-class flares on 4-5 April.

We always look for a low Kp index over a higher solar flux index for better HF conditions.

So how does this all affect HF propagation? The maximum useable frequency, or MUF, over a 3,000km path has been struggling to get up to 28MHz on most days. This leaves only 21MHz and 24MHz open after the initial post-dawn ionospheric build-up.

This doesn’t mean that 10m is dead but it may be that the band is only open to DX and not open to Europe.

This may change once the Sporadic-E season starts but we are still a month away from that.

DX being worked, according to the CDXC Slack group, includes 5W1SA in Samoa on 17m FT8, F0/F6BCW from French Polynesia on 12m CW and 3DA0TM in Eswatini on 20m USB. T31TTT on Kanton Island, Central Kiribati, has also been spotted on the 20 and 30m bands using FT4 and FT8.

The DXpedition is focusing on FT modes, although the team is also operating some CW.

Next week, NOAA predicts that the solar flux index will start around 105 but will increase a little over the week to reach the low 120s.

Geomagnetic conditions are forecast to be quiet, with a maximum Kp index of 3 once we get over this weekend’s predicted disruption, which has a forecast Kp index of 5.

Then we are in for a rough ride next weekend, with a predicted Kp index of 6 on 19 April and disrupted conditions for three days. This is likely due to the return of active region 4392, which produced a coronal mass ejection that hit the Earth and caused the Kp index to rise to 7 on its last rotation.

VHF and up propagation news from G3YLA and G4BAO:

The warm, dry weather of the middle of last week has left us with ideas of spring but it has now been replaced by cooler, unsettled weather with rain or showers.

In fact, the next week or two will be generally unsettled, not atypical of April. This will be a good period for rain scatter on the upper GHz bands since April showers can be heavy and present good scatter opportunities.

This unsettled weather means tropo retreats into the background for this period.

Meteor scatter is still under the influence of random activity and best in the early morning hours. Aurora is currently looking more promising with solar conditions offering coronal holes and possible auroras as a result.

Sporadic-E will start to make an appearance soon, especially on the 10m band, but realistically, we probably need to wait until we are into May before chances are more rewarding for the 6m band.

It is often a feature of the early part of the Sporadic-E season that the traditional two periods of activity of the high season, morning and afternoon, start off as one broad period around the middle of the day.

For EME operators, Moon declination is starting to climb again, going positive on Wednesday, 15 April. Earth-Moon-Earth path losses are past maximum now and continue to fall all week.

144MHz sky noise is high today, 12 April, and will fall to low for the rest of the week. Friday, 17 April will be an exception as the Moon and Sun will be close in the sky.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/04/10/propagation-news-12-april-2026/

(Mike Terry/BDXC) 

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor

  April 2, 2026

Over the last week, we have had a fair sprinkling of sunspots, along with some enormous coronal holes, including one almost rectangular hole. 

Coronal holes are lower-energy areas on the Sun with open magnetic field lines, allowing solar plasma to flow out.

Geomagnetic conditions have mainly been settled, with the Kp index hitting a maximum of 3.67 over the past five days.

We had a long M1.3 solar flare at 0415UTC on Saturday, 28 March, and an

X1.5 class solar flare on Monday, 30 March.

Active region 4405 erupted at 0318UTC and launched a halo coronal mass ejection, or CME, into space that hit the Earth on Wednesday, 1 April.

Meanwhile, the solar flux index has remained above 140 for a few days, which bodes well for HF propagation.

NOAA predicts that the solar flux index will start at 145 at the beginning of the coming week and fall to 112 by Saturday, 11 April.

Geomagnetic conditions are set to be unsettled from Thursday to Sunday,

9-12 April, with a potential Kp index of 5 or even 6.

If this comes to pass, expect lower maximum usable frequencies, or MUFs, and disrupted HF conditions, especially on polar paths.

HF DX to look out for this week includes:

VHF and up propagation news from G3YLA and G4BAO:

The equinoxes are a time of the year when the Atlantic jet stream typically blows across the UK as it migrates north from the Mediterranean in the winter to near Iceland in the summer.

The weather for the coming week is going to see a succession of lows driven by the Atlantic jet stream crossing the UK with bands of rain and scattered blustery showers.

These may represent chances of some rain scatter for those on the upper GHz bands but this pattern suggests limited tropo options.

The prospects for meteor scatter are no better since we remain some way short of the next major meteor shower in late April. In these situations, your best chances are from random meteors, which tend to peak in the early pre-dawn hours.

The equinox also gets credit as being a preferred time for auroras since there is a better coupling between the Earth’s magnetic field and the solar wind.

It is too early in the year for much Sporadic-E activity, but keep a check on the Sporadic-E graphs on propquest.co.uk  for signs of brief upticks. Incidentally, some maintenance work is currently under way on the website so apologies for any interruptions.

For EME operators, Moon declination is now negative, reaching its minimum on Wednesday, 8 April. At this point, the Moon is up for only six hours and gets to a mere nine degrees elevation in the UK.

The Moon is also furthest away, or at its apogee, on Tuesday, 7 April so path losses are at their highest. 144MHz sky noise starts low but quickly climbs to a high of more than 2,700 Kelvin on Wednesday, 8 April.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/04/02/propagation-news-5-april-2026/

U.K. Propagation Update

 

RSGB

By RadCom Assistant Editor

March 27, 2026

After last weekend’s HF disruption, the latter half of the week was fairly settled.

Last weekend, the Kp index rose to 7, sparking visible aurora around the UK. The disruption continued, on and off, until Tuesday, 24 March, when the Kp index fell below 3 again.

The disruption was caused by a solar wind stream that had a Bz pointing south and reached speeds of more than 600km/second. The south-pointing Bz meant it was more easily coupled with the Earth’s magnetic field, hence the disruption.

Meanwhile, the solar flux index has picked up, rising from being in the 100s to hit 140 on Thursday, 26 March.

This, combined with a lower Kp index, has helped the ionosphere and we saw better maximum usable frequencies, or MUFs, over a 3,000km path later in the week.

But the threat of more geomagnetic disturbances has not gone away. Two large coronal holes are now Earth-facing and threaten to push the Kp index up once again.

NOAA predicts that the Kp index could rise to 4 on Monday, 30 March, and 5 on Friday and Saturday, 3-4 April.

The solar flux index is predicted to fall into the 130s and 120s again during the coming week, although this is still enough to provide good ionospheric propagation.

This may be your last chance to work the CY0S Sable Island DXpedition off the coast of Nova Scotia, which ends around Tuesday. 31 March.

Other DX stations to work this week include S21WD in Bangladesh, OX3LX in Greenland, CE0Y/DJ4EL on Easter Island, YJ1JXZ in Vanuatu, XX9W in Macao, T31TTT on Kanton Island and V4/SP9FIH from St. Kitts.

To recap, March and April are good months for North-South HF propagation, although we may see MUFs fall slightly with 10m band openings becoming rarer, at least until the Sporadic-E season starts in May.

VHF and up propagation news from G3YLA and G4BAO:

The current period of rather more changeable weather will continue to be the main weather pattern during the rest of the month.

However, with a large area of high pressure to the west of the UK, there will be times when the weather feels more settled and possibly with a hint of tropo briefly just before midweek.

For the rest of the time, active weather fronts will bring occasional bands of rain or showers with the possibility of some rain scatter for GHz operators.

Spring is always a good time to keep an eye on aurora since the geomagnetic disturbances are more likely around the equinox.

The Kp index, which describes the state of the Earth’s magnetic field, increases at times of potential aurora. So remember that once the Kp index gets above 5, it’s worth monitoring the bands for signs of fluttery or raspy signals.

Meteor scatter is still under the influence of random activity. As we head into April, we are getting closer to the next important meteor shower, the Lyrids, toward the end of the month.

Sporadic-E is currently in a dormant state so we are not expecting that to feature much in reports for another month. However, if you feel the need to check, use the comprehensive 10m beacons distributed around Europe to see the state of the upper HF bands for early signs of Sporadic-E propagation.

Last week was a busy one for EME with the Dubus 5.7GHz activity and the

CY0 and T7 DXpeditions are being worked by many.

Moon declination starts the weekend high, dropping to negative on Tuesday, while path losses continue to increase towards apogee on Tuesday, 7 April. 144MHz sky noise is low all week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/03/27/propagation-news-29-march-2026/

(Mike Terry, UK/BDXC)

U.K. Propagation Update

RSGB

RadCom Assistant Editor | March 20, 2026

Last weekend’s Commonwealth Contest got off to a bad start, thanks to a Kp index of 6 that really affected the ionosphere.

As a result, HF conditions were not good with the maximum usable frequency over a 3,000km path below 21MHz until 1700UTC. Luckily, things improved a little on Sunday but overall scores were down compared with previous events.

The Kp index increase was due to a coronal hole stream which reached 600 to 700km/second and a Bz that pointed south. The equinox period hasn’t helped due to the Russell-McPherron effect, a phenomenon that occurs when the Earth’s magnetic field aligns with the Sun’s magnetic field during equinoxes, creating ‘cracks’ in the magnetosphere.

Otherwise, the week has been unremarkable. The solar flux index has remained firmly in the 110s and there have been no X-class solar flares, only a few M and lesser C-class events.

Next week, HF propagation may be dominated again by the solar wind. Coronal hole number 33 will begin to face Earth and a high-speed stream was predicted to reach us this weekend, ending today, 22 March. A coronal mass ejection was also predicted to arrive around Thursday, 19 March.

NOAA predicts the Kp index will rise to 5 this weekend and not decline to 3 until 26 March. Meanwhile, the solar flux is predicted to remain in the 105 to 120 range until 27 March. It may then increase slightly to be in the 120s until the end of the month.

As a result, expect lower maximum usable frequencies and poorer HF conditions until around next Thursday and Friday, 26-27 March.

VHF and up propagation news from G3YLA and G4BAO:

The high pressure that developed during the second half of last week formed on the warmer side of the front and as a result produced slightly better tropo conditions than looked possible the previous week.

The weather is probably going to try to change to a colder air high in the coming week, so expect conditions to decline. However, that’s not the only reason for a decline.

As the main high centre displaces west of Britain, we will find a colder and unsettled west or northwesterly pattern affecting the UK next week. So less tropo, but more chance of some rain scatter for the upper GHz bands.

Meteor scatter remains in the random activity domain, although we are edging closer to the next major shower of the late April Lyrids.

It’s not to say that exciting things can’t happen, however. Just after a HamSCI workshop on the subject of meteor scatter last weekend, a multi-ton meteoroid was reported from Cleveland, Ohio, on the HamSCI Google groups at around 1300UTC on 17 March.

This produced a sonic boom and was visible in broad daylight.

All is quiet on the Sporadic-E front, although we are slowly moving towards a period when the first glimmers of activity show themselves, particularly on digital modes.

Lastly, a comment on the chances of aurora. These are usually enhanced due to solar-terrestrial alignment around the equinoxes and with two coronal mass ejections predicted to arrive at the tail end of last week, ending today, 22 March. As usual, check for an increasing Kp index above 5.

For EME, yesterday saw the 5.7GHz section of the Dubus CW and SSB EME contest and associated all-mode activity weekend.

With Moon declination positive and rising, and path losses still low, it hopefully produced some nice contacts.

On VHF, 144MHz sky noise is low in the coming week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/03/20/propagation-news-15-march-2026-2/

(Mike Terry, UK/BDXC) 

U.K. Propagation Update

 

RSGB

February 20, 2026

We had a week of relatively low solar flux indices and mostly settled geomagnetic conditions.

While the solar flux index fell to be in the 117 to 129 range, the Kp index was mostly in the twos and threes. This was after the weekend’s geomagnetic disturbance due to a large coronal hole that expelled solar plasma in a stream that moved past Earth at nearly 700km per second.

As a result, HF conditions have been quite good with plenty of DX being worked.

The KP5/NP3VI Desecheo Island DXpedition near Puerto Rico has been a struggle for many, due to its popularity and use of solar-powered batteries and low power.

One quick hint: try FT8 on the 40m band around 7am to 7.30am. You get a greyline enhancement at sunrise but for much of Europe the band is closing, which means there is little competition.

Let us know how you get on.

Other DX this week includes 8R1WA in Guyana. This is an Italian team operating until Friday, 27 February. Chuck will be active as VP2MCV on Montserrat and will be active in the ARRL DX CW Contest and until the end of the month.

A German team will be operating as J51A in Guinea-Bissau until mid-March.

Another large solar coronal hole became Earth-facing on Friday, 20 February, so we may expect unsettled geomagnetic conditions from today,

22 February.

Next week, the Space Weather Prediction Centre forecast a low solar flux index of 105 for yesterday, 21 February, before rising again to potentially reach 165 by the end of this month.

Unsettled geomagnetic conditions are forecast for 24-25 February with an estimated Kp index of 5.

VHF and up propagation news from G3YLA and G4BAO:

Friday, 13 February and Saturday, 14 February, saw afternoon openings on 50MHz to TZ1CE in Mali to generate DX interest.

However, as expected, it was stations much further south that benefited from the best propagation, with just a few stations in the southern areas of the UK making QSOs on FT8.

The present spell of unsettled weather remains the main theme for the period up to the end of the coming week.

The pattern is controlled by a strong Atlantic jet stream so ‘changeable’ is the watchword with periods of heavy rain alternating with brighter showery interludes and, of course, quite strong winds at times.

In terms of propagation, rain scatter is a clear favourite, although in one cloudy period in mild air around Tuesday, 24 February, some possible tropo may show up for the southern areas of UK.

The meteor scatter options are again subject to random activity since we are still some way off the next important shower, the Lyrids, in late April.

The auroral prospects have, at best, been gently simmering at low values of the Kp index, mostly less than 5. Stay tuned though, because we may see an uptick around Tuesday, 24 February.

So watch for signs of fluttery signals on the LF bands and then check for auroral tones on 10m and up through the 6m to 2m bands.

These events are always a bit of a long shot but should be worth checking this time.

The sporadic-E season is still some way off, although a strong jet stream pattern is always a positive.

For EME, Moon declination is positive and rising, meaning longer Moon windows and higher peak elevation. Path loss continues to fall as we approach perigee on Tuesday, 24 February. 144MHz sky noise starts the coming week low, rising to moderate towards the end.

And that’s all from the propagation team this week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/02/20/propagation-news-22-february-2026/

(Mike Terry, UK/BDXC)

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | January 9, 2026

Now that the dust has settled after the New Year’s celebrations, we can get back to our regular propagation reports.

The New Year has started with minor disturbed geomagnetic conditions at times, plus lots of C-class solar flares, and a healthy dose of sunspots. As we slide down the slope towards sunspot minimum, we can expect more geomagnetic disturbances and raised Kp indices. But we should still have good HF conditions for a couple of years.

The Kp index hit 5 on 2 January, but has otherwise been relatively quiet, often registering less than 1 or 2. And the lack of M- and X-class solar flares means we have had no solar fade-outs.

With the solar flux index at more than 150 for much of the time, this bodes well for HF propagation and, as Propquest shows, the maximum usable frequency over 3,000km during daylight has often been more than 28MHz.

Unfortunately, this does decline quite quickly after sunset, leaving the maximum usable frequency below 10MHz most of the time. As we head towards spring, we can expect this to improve.

DX has been available. Stations worked include V51WH in Namibia on the 12m band using SSB, TZ4AM in Mali on 30m using CW, and ZS7ANF in Antarctica using CW on the 17m band.

Next week, NOAA predicts that the solar flux index will be in the 130 to 150 range.

Geomagnetic conditions are forecast to be variable, with the Kp index predicted to hit 5 on 13-14 January, and again 17-20 January.

So, we recommend you get your HF DXing in before 13 January and around 15-16 January, as propagation and maximum usable frequencies will no doubt be affected if the Kp index rises.

With the three-week 3Y0K Bouvet Island DXpedition set for early February, now may be a good time to sort out your antennas. Remember that Bouvet is almost due south from the UK, so plan accordingly. More propagation details will be made available nearer the time.

VHF and up propagation news from G3YLA and G4BAO:

The unsettled weather pattern continues to provide a variety of challenging weather types with heavy snow and rain, plus strong winds at times.

The nature of such patterns in January is that the timing and track of the lows are critical for the rain and snow outcome. Overall, it’s likely to be a cold system week with occasional brief milder interludes as Atlantic fronts move through in the middle of the coming week.

The effect on VHF and UHF propagation is limited with tropo unlikely, but there is a significant chance of rain or snow scatter at times for GHz operators.

There have been some slight increases in the Earth’s Kp index, which responds to solar activity. However, as we are between the peak periods of autumn and spring for aurora, it’s probably not a major player this time.

Meteor scatter has been a bit more interesting lately due to the peak of the Quadrantids meteor shower on 4 January. The shower has a short, intense peak, but spans the period from 28 December to 12 January. The next major shower isn’t until April, so it’s back to random activity from this weekend through to the late April Lyrids.

Lastly, a reminder that mid-winter Sporadic-E does happen. 6 January saw a nice early evening 6m band opening to the Baltic states, moving round to Ukraine and the Balkans later.

Recent Quadrantids meteors may have contributed some long-lived metallic ions, which can be focused into thin Sporadic-E patches. It’s always worth checking the Sporadic-E Layer Critical Frequency values plotted on the Propquest graphs for short spikes in the purple trace, which could be a sign of potential interest in Sporadic-E on the 10 and 6m bands.

For EME operators, Moon declination is negative again and we are past perigee, so path losses are increasing and Moon window length and peak elevation are reducing. 144MHz sky noise remains low but rising to high by Friday, 16 January.

And that’s all from the propagation team this week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/01/09/propagation-news-11-january-2026/

(Mike Terry, UK/BDXC)

UK Propagation Report

 

RSGB

RadCom Assistant Editor | December 24, 2025

We have had some solar ups and downs over the past week. A high-speed stream from a large coronal hole has kept the Kp index high at times, plus the solar flux index has been relatively low due to a lack of sunspots.

The coronal hole has been massive, covering from the Sun’s south pole right up to and past the solar equator.

Nevertheless, there has been DX about, including PZ3OZ in Surinam on 80m FT8 and 40m CW, ZS7ANF in Antarctica on 30m CW, and TG9ADM in Guatemala on 10m CW.

Also spotted have been some of the ‘12 Days of Christmas’ stations in the US, including W2R/5 in Arizona on 15m CW.

Let’s take a look at HF propagation over the next two weeks.

According to NOAA, we may be in for a bumpy ride. The Kp index is predicted to rise to six on 30 December and stay high until early January. Meanwhile, at the same time, the SFI is predicted to rise to 170.

The best time for HF may be after 3 January, when the Kp index is predicted to fall to a more reasonable two to three, while the SFI remains in the 150-160 range.

There should be plenty of activity on HF, with the G-QRP club’s Winter Sports running up until 1 January, and a whole range of contests, from the RSGB’s AFS CW Contest from 1300UTC to 1700UTC on 3 January, to the Marconi Club ARI Loano QSO Party from 0700UTC until 2100UTC, also on 3 January.

Keep an eye on www.contestcalendar.com for updates.

We hope you have a happy New Year and look forward to bringing you more HF propagation news in 2026.

VHF and up propagation news from G3YLA and G4BAO:

The Christmas week saw a brief cold easterly around Christmas Day, then milder air returned around the top of the large area of high pressure.

We go through the next week with the high pressure just to the north or west of Britain and this will bring a more northerly flow across the country and, although initially milder, will become much colder again for the second half of next week.

Since it is primarily a high-pressure week, there’s always a chance of Tropo, but not everywhere. It’s suggested you look for regions of cloud and fog for the best paths since it shows there is moisture under the inversion … a good thing for Tropo.

The solar conditions are likely to offer prospects for aurora and since this period is between two meteor showers with the second one, the Quadrantids, peaking on 4 January at the end of the week.

Finally, a note to follow up on last week’s heads-up for mid-winter Sporadic-E. It’s certainly worth checking for digital modes and quite possibly for SSB/CW on 10m and 6m if there are signs of activity.

For EME operators, Moon declination is rising again and path losses are decreasing as we head towards perigee on 2 January, the point where the Moon is closest to Earth. 144 MHz sky noise remains low until 14-18 January.

And that’s all from the propagation team this week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/12/24/propagation-news-28-december-2025/

(Mike Terry, UK/BDXC)

U.K. Propagation Update

 

RSGB Propagation News - 14 December 2025

We had a bit of everything last week, including increased Kp indices, a high solar flux, an X-class solar flare and coronal mass ejections.

The solar flux index hit a maximum of 220 on Thursday, 4 December. This brought good HF conditions until Sunday, 7 December. The index declined to 169 on Thursday, 11 December, which was still more than enough to excite the ionosphere.

We had an X-class solar flare at 0501UTC on Monday 8 December. This originated from large active region 4298, which has now rotated out of view. We also had more than ten M-class solar flares over the past week, showing that the prediction of disturbed conditions on the downward part of the solar cycle still holds true.

The Kp index hit 6.33 on Wednesday, 10 December, which disrupted maximum usable frequencies, or MUFs. The net result was that digisonde traces were missing at times, with the MUF over 3,000km being in single figures on Thursday, 11 December.

To cap it all, we now have a very large Earth-facing coronal hole that threatens HF propagation today, 14 December.

There has been DX around, but mostly on the lower bands. CDXC’s Slack group reports that KP2B on St Croix was worked on the 80m band using FT8 on the morning of Thursday, 11 December. TO9W on St Martin was logged on the 40 and 30m bands using CW on Tuesda,y 9 December. TT1GD in Chad also appeared on the 40m and 20m bands using CW on Monda,y 8 December.

Next week, NOAA predicts the solar flux index will be in the 130 to 140 range. However, as was mentioned earlier, geomagnetic conditions may be disturbed today, 14 December, due to a fast solar wind stream from a coronal hole.

Conditions might calm down from the 15 to the 20 December, before the Kp index hits 5 around the 21 to 26 December.

In summary, get your HF DXing in during next week, before auroral conditions take their toll over the Christmas period.

VHF and up propagation news from G3YLA and G4BAO

The present period of unsettled weather will remain the driving force for weather conditions for most of the country for the period up to Christmas.

This will mean that there are likely to be some very windy spells with extensive rain and squally showers. It offers scope for rain scatter operators on the GHz bands, but scarcely any hint of good tropo conditions.

One item of interest is the meteor scatter prospects from the Geminids, which peak today, 14 December. It is one of the busiest showers of the calendar with a peak hourly rate of 120, so it should provide plenty of opportunities and is worth exploring during the week before and following the peak.

The solar conditions have again remained interesting enough with a red alert on the evening of Wednesday 10 December, and there is always the potential for the Kp index to produce signs of auroral radio activity once it goes above 5.

Finally, a reminder that this winter period, from mid-December to mid-January, can produce some surprisingly effective Sporadic-E. It’s possibly easiest to see by checking the propquest.co.uk  graphs to 

see if the foEs trace is showing any sharp spikes.

The 10 and 6m bands are probably the more likely bands to show signs of activity in these winter events, but it’s certainly worth checking if the graphs show any promising signs.

For EME operators, Moon declination went negative on Friday 12 December, meaning shortening Moon windows and decreasing peak elevation. We are past perigee for the month, so path losses are increasing. 144MHz sky noise starts low but increases to high by Friday 19 December when the Sun and Moon are close in the sky.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/12/12/propagation-news-14-december-2025/

(Alan Pennington, UK/BDXC)

U.K. Propagation Update

 

RSGB 

RadCom Assistant Editor | November 14, 2025 

Last week saw one of the most dramatic auroral events of this cycle. Three X-class solar flares, which sparked coronal mass ejections, joined together to give us a peak Kp index of 8.67, with a solar wind speed in excess of 950 kilometres per second.

The result was extensive visible aurora in the US and Canada, although clouds prevented much of its visibility in the UK. The good news from a radio point of view was that the solar wind’s Bz, or interplanetary magnetic field, mostly pointed north or was neutral in the latter stages. This saved the Earth from a lot of its effects.

The next day, HF propagation appeared to be almost normal with maximum useable frequencies, or MUFs, over a 3,000km path still exceeding 24MHz at times. By Thursday, 13 November, it was mostly over 28MHz, although there were times it dropped dramatically, and signals were weak and watery at best.

You could tell that there had been some disruption to HF by a lack of spots on the CDXC Slack group. While Stan, ZL7/LZ1GC on Chatham Island had been spotted on 11 November, there was very little to report the next day as the Kp index rose to 5.

Next week, NOAA predicts that the solar flux will remain in the 160 to 170 range. However, we can expect a repeat of unsettled geomagnetic conditions this weekend, possibly due to a large coronal hole that became Earth-facing on 13 November.

Likewise, Thursday, 20 November and Friday, 21 November may be unsettled, with a predicted maximum Kp index of 4. After the following weekend, we can also expect more unsettled conditions, especially around 24-27 November, which could see the Kp index rise to 5 or even higher.

Expect decreased MUFs and less HF activity if this is the case.

VHF and up propagation news from G3YLA and G4BAO:

The current spell of unsettled weather is likely to continue into the coming week.

High pressure is always being kept at arm’s length, so there is no real tropo flavour to proceedings. The rain prospects are very strong with, if anything, too much rain in some areas.

During the coming week, colder northerly air will mean that some snow is possible on northern hills. So there remains a possibility of rain scatter on the GHz bands.

After the recent auroral activity, the prospects are worth considering, although it would be surprising if a repeat of the exceptional event of last week were to happen. Nonetheless, stay alert to the Kp index going above 5 and check for activity on the 10, 6, 4 and 2m bands.

The event of last week was triggered by three successive days of X-class flares so for an early ‘heads-up’, start with the Sun.

The foEs graphs on propquest.co.uk  were interesting for the evening of the Autumn Series contest on 12 November. There were some rapid changes in propagation as paths were affected by the F2-layer one minute and Sporadic-E the next.

It is occasionally worth examining the graphs now and again to relate perceived conditions from the radio speaker to actual measurements of the ionosphere. Of course, the data from Dourbes is not necessarily what would have been recorded over the UK, but it gives a good flavour.

The takeaway message is that although we think of Sporadic-E as a summer phenomenon it can play a role outside the main season.

Meteor scatter is certainly in the frame this week since the Leonids meteor shower is due to peak tomorrow, 17 November. Since meteors also play a part in Sporadic-E propagation, there is another reason to check the foEs graphs for out-of-season activity.

For EME operators, the Moon’s declination went negative again yesterday, 15 November, so Moon window lengths and peak elevation fall accordingly. Path losses are increasing to a maximum at apogee on Thursday, 20 November. 144MHz sky noise is low during all of the coming week except for the 

whole of Thursday, when the Sun and Moon are close in the sky.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/11/14/propagation-news-16-november-2025/

(Mike Terry, UK/BDXC) 

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | November 7, 2025

Last week was a mixed bag in terms of HF propagation. Earlier in the week, the 10m band was working very well, with Australia romping into the UK by mid-morning. But later in the week, everything had changed.

Solar activity was high with multiple X-class and strong M-class solar flares. At least three coronal mass ejections, or CMEs, were expected to graze or directly hit Earth, sparking strong geomagnetic storms on Thursday and Friday, 6 and 7 November.

The X-ray flare on Wednesday, 4 November was the first seen since June and came from active region 4274 – a large sunspot group which helped push the solar flux index to 147.

The Kp index climbed to 6.67 in the early hours of Thursday. Later that morning maximum useable frequencies, or MUFs, were badly affected, with a maximum of 18MHz over a 3,000km path as a strong G3 geomagnetic storm was in progress. So, it looks like good DX on the higher bands may be off the cards for a few days.

However, one interesting contact was noted on the CDXC Slack chat group when ZL7/LZIGCC was spotted on 14.005MHz using CW at 10.30am on Thursday.

Interestingly, the current solar activity is nearly all in the Sun’s northern hemisphere, so are we heading for a second peak in Cycle 25?

Next week NOAA predicts that the solar flux index may decline to be in the 130 to 145 range. Geomagnetic conditions are predicted to remain unstable until around Wednesday, 12 November.

With active region 4274 rotating to be more Earth-facing we may expect more solar activity, such as solar flares and coronal mass ejections, before things quieten down.

VHF and up propagation news from G3YLA and G4BAO:

We are becoming well acquainted with mild, unsettled weather and as a result there were plenty of rain scatter options on the GHz bands in the last week. These are likely to continue through the coming week.

Tropo is not completely out of the frame in the extreme south and east, albeit fleetingly, but for most of the UK it is unlikely to be a strong feature.

As in recent weeks, there are a few auroral alerts coming through but so far nothing too dramatic showing up on the VHF bands. Meteor scatter looks more interesting as we move into mid-November. The Leonids, one of the more important meteor showers in the calendar, peaks just after next weekend on Monday, 17 and Tuesday, 18 November, so we should expect to see some increasing activity as we progress through the coming week.

The UK Activity Contest events feature 432MHz on Tuesday, 11 November when the eastern side of the UK may have one of the fleeting moments of tropo to the east and south. Later in the week, on Thursday, it’s the turn of 50MHz.

Conditions look weaker for tropo for the 50MHz UK Activity Contest, but still favour the extreme east of England, if there is any left by then. It is possible that meteor scatter or even aurora might come to the rescue for this one.

For EME operators, the Moon’s declination is at its highest this weekend, ending today, 9 November, so Moon window lengths and peak elevation are also at their greatest. Path losses are now increasing as we passed perigee on Wednesday, 5 November. 144MHz sky noise is low and at its lowest midweek.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/11/07/propagation-news-9-november-2025/

(Mike Terry, UK?BDXC)

U.K Propagation Update

 

RSGB

GB2RS News Team | October 9, 2025

We finally got rid of the high-speed solar wind stream, which caused havoc on the HF bands. But we are not out of the woods yet!

Last week saw the Kp index hit 6.67 on 2 October, and it was often up around 4 or more. Even though the Kp index eventually reduced, the ionosphere took its time to recover and things were not back to near normal until Tuesday 7 October.

Meanwhile, the solar flux index decreased to 131 by 8 October, so the HF bands were hardly humming by this time.

DX on the 10m band was hard to find. Openings to Europe were commonplace but longer paths were not so good, with only weak North American stations being heard later in the day.

A minor G1 geomagnetic storm watch was in effect for 48 hours from 7 October when at least one faint coronal mass ejection was predicted to pass the Earth. Only minor C-class solar flares occurred during the week, but that didn’t help too much.

CDXC members were reporting DX, such as V85T in Brunei on 15m and A52G in Bhutan on 20m – both using CW. However, there was not much to work on the higher bands. Southerly paths were a little better with 5X2I in Uganda reported on the 17m band using FT8.

Next week, NOAA predicts that the solar flux index will be in the range of 130 to 140, but it is also predicting geomagnetic disturbances today,

12 October. After that, the Sun may quieten a little with a maximum Kp index of 2 for the rest of the coming week before more geomagnetic disturbances. The Kp index is forecast to be 4 or 5 during the weekend of 18 and 19 October.

VHF and up:

The coming week is dominated by high pressure, either over the UK or near enough to influence the propagation and provide a prolonged period of Tropo weather.

It’s probably worth mentioning a few ground rules about Tropo operating. 

Firstly, large areas of high pressure can produce widespread lift conditions due to the strength of the elevated temperature inversion 1 to 1.5km above the ground. The longer the high lasts, the lower this descends, so limiting maximum distance across the centre of the high.

Try beaming around the edge rather than across the centre. Secondly, there may be surface temperature inversions at night or in foggy weather, and these will provide temporary enhancements. Thirdly, the clue for a good ‘radio’ temperature inversion is the presence of fog or layers of cloud which give a better moisture contrast and ducting prospects.

One last point. Try other modes like SSB or CW rather than sticking to repeaters which can get very crowded in lift conditions.

There is no rain scatter in the frame this week and the Draconids meteor shower has just passed, so back to random activity on that front. On 8 October the Sporadic-E graphs at propquest.co.uk  showed that there had been occasional spikes up to 5MHz or so. This may liven up the 10m band if we get any more. There have been a few weak auroral events but nothing too exciting.

For EME operators, the Moon’s declination is still increasing, reaching its peak today, 12 October, so long Moon windows and high peak elevation continue. Path losses are rising again after perigee on the 8 October. 

144MHz Sky noise will be moderate to low for the coming week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/10/09/propagation-news-12-october-2025/

(Mike Terry, UK/BDXC)

U.K. Propagation Update

 

RSGB

GB2RS News Team | September 26, 2025

Last week was good for HF propagation for a number of reasons. Firstly, we are now entering autumn, which offers better propagation prospects than summer. Secondly, the solar flux index has remained high at up to

184 as of last Thursday, 25 September.

We had a week of near-normal geomagnetic conditions, with a low Kp index, no Earth-directed coronal mass ejections, and a relatively quiet solar wind.

These have all combined to give excellent HF propagation, including openings on the 10m  band using FM and transatlantic 10m contacts being possible in the afternoon.

The maximum useable frequency, or MUF, over a 3,000km path, according to Propquest, has mainly been in excess of 30MHz during daylight hours.

The KQ2H repeater in upstate New York, with an output frequency of 29.620MHz, has been loud at times in the afternoon and is a good indicator of HF propagation. Expect it to get better as we enter October. Other US stations have also been heard on the 10m band using FM, including one in Ohio.

Steve, G0KYA was surprised to hear the GB3XMB 10m beacon on 28.287MHz from Waddington, Lancashire this week. Steve remarked that it is 175 miles to Norfolk as the crow flies. He said that the signal didn’t sound like backscatter, so that’s quite a distance for 10m ground wave.

Other DX worked, according to CDXC, included FP5KE, the St. Pierre and Miquelon DXpedition. The station could heard on everything from Top Band to 10m.

V6D in Micronesia has been working on the 40 and 17m bands using CW.

Other highlights include D2USU in Fiji on the 12m band using FT8, and 9Y49R in Trinidad and Tobago on the 10m band using FM.

Next week, NOAA predicts the solar flux index may fall to be in the 159 to 170 range. Geomagnetic conditions are predicted to be poor tomorrow,

29 September, with a Kp index of 5, and again between the 3 and 5 October, also with a predicted Kp index of 5. Expect decreased MUFs for a few days until the ionosphere recovers.

VHF and up:

The next week or so looks to be typical for autumn. It will be a mix of Atlantic weather systems bringing lows and their fronts which may offer some rain scatter for those on the GHz bands.

The other side of the coin is areas of high pressure or mostly weak ridges, in this case mainly affecting the south and east of the country. 

This is the point where Tropo operators can move in with paths probably favouring the North Sea and Scandinavia up to this weekend and then across to the continent and down to Spain during the coming week.

It is worth remembering that Tropo can exist throughout the 24 hours across water and along coasts like the North Sea and English Channel, although the portion of a path overland can weaken during daytime.

The meteor scatter prospects remain in the random territory, so they are best in the early morning.

Recent activity with geomagnetic disturbances suggests that aurora should continue to be part of the operating list in the coming week. 

Check for a hollow note or warble on HF signals and for a Kp index greater than 5, then consider turning your VHF arrays to the north.

For EME operators, Moon declination reaches its minimum tomorrow, 29 September, so from then on we will see lengthening Moon windows and increasing peak elevation. The Moon’s distance from Earth started to decrease after apogee on Friday, 26 September, meaning path losses are falling. 144MHz Sky noise will be high today, the 28 September, and peaks at around 2800 Kelvin tomorrow, 29 September, before dropping back to low for the rest of the week.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/09/26/propagation-news-28-september-2025/

(Mike Terry, UK/BDXC)

U.K .Propagation Update

 

RSGB

June 26, 2025

The last week was good from a geomagnetic disturbance point of view. Up until Wednesday, the 25th, the Kp index had not been higher than 3.67, and had mostly been in the ones and twos. This helped HF propagation to a great extent.

Sunspots have been present with the solar flux index sitting at 120 on Wednesday, the 25th. A look at the visible disk at solarham.com shows five sunspot groups facing Earth. None are groundbreaking, but they are at least helping to keep the solar flux index relatively high.

Daytime F2 MUFs over a 3,000km path have been reaching 18MHz and even 21MHz at times, with 14MHz being more reliable. Sporadic E continues to make 28MHz a useful band for short-skip, with much of Europe being workable mid-morning on the 25th, at least using FT8.

Estonia, Germany, Poland, and Finland were all easily worked on FT8, but nothing was heard on the usual 10m CW and SSB frequencies.

Next week, NOAA predicts that the solar flux index will be in the 140 to 150 range. Unsettled geomagnetic conditions are forecast for 1 to 3 July, when the Kp index could reach 4. Conditions may become unsettled again on the 6th and 7th again with a predicted Kp index of 4.

But in the meantime, make the most of the sporadic E on the 10m band, as it won’t last forever!

VHF and up propagation news from G3YLA and G4BAO :

The more traditional summer weather, with patchy rain and showers, is likely to continue for a bit longer. The more persistent rain is likely in the north closer to low pressure near Iceland, whereas the rain may be more intermittent in southern areas, closer to high pressure over France.

This probably rules out any significant tropo in northern Britain over the coming week but does allow for the occasional enhancement in the southern half of the country. Most areas will have some rain scatter opportunities for the GHz band operators—although perhaps fewer in the south than in the north.

The solar conditions have quietened down a little in terms of aurora recently but, as we said last week, don’t forget to look north in the twilight sky for signs of the pale noctilucent cloud. This is a high summer phenomenon. See if you can detect any wave patterns—like ripples on a sandy beach—in the cloud.

The month of June tends to be quite good for meteor input and the last of the set, the June Bootids, peaked on Friday, the 27th. So, there should be some good chances for hearing the odd ping or two, or even seeing one in the evening sky after dusk.

The primary mode of interest is still sporadic E, which is in full swing and doubtless being topped up by the Bootids meteors, which produce the main ingredient of sporadic E propagation—long-lived ions—as they ablate, or burn up, upon entering the atmosphere.

In terms of the usual search for placement of sporadic E events geographically, the main jet stream interest is likely to be across the northern part of Europe for the coming week. This suggests trying paths to Scandinavia and the Baltic states, whereas for triggers due to upper air ridge patterns use the more southern routes.

The Moon has passed perigee for this month, so path losses are rising. Moon declination is still high, not going negative until Tuesday, 1 July. 144MHz sky noise is low, increasing to moderate by next weekend.

 

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/06/26/propagation-news-29-june-2025/

(Mike Terry/BDXC) 

UK Propagation Update

 

RSGB

GB2RS News Team

 April 17, 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 plasma density was noted as well. Subsequently, the Kp index peaked at 7.67 on Wednesday 16 April, causing visible aurora alerts in the UK.

This was caused by a pair of CMEs that left the Sun on Sunday 13 April. We had a total of 22 M-class solar flares over four days, so a CME event was inevitable.

Unsettled geomagnetic conditions are a feature on the declining side of a solar cycle, so we could unfortunately be in for many more.

According to Propquest, MUFs over a 3,000km path fell to below 18MHz for long periods on Wednesday 16 April , before climbing to around 21MHz at the end of the day.

Meanwhile, the solar flux index fell from a high of 170 on Friday 11 April to a low of 148 on Wednesday 16 April.

Next week, NOAA predicts that the SFI will start the week around 145 but could increase to 165 as the week progresses. Unsettled geomagnetic conditions are forecast for the 22 to the 24 April, with a predicted maximum Kp index of four.

As always, keep an eye on solarham.com for daily updates, but more importantly, get on the bands, which are a much more effective guide to HF propagation!

VHF and up :

The current period of unsettled weather looks likely to continue into the coming week. This does not mean rain every day, but periods of rain or showers with some intervening drier spells. These drier interludes are not really dominated by high pressure, just gaps between the wetter periods, so it’s unlikely to produce much significant Tropo.

In terms of propagation, there may be some rain scatter, although it won’t be very reliable. However, the prospects for meteor scatter are more promising with the peak of the Lyrids due on Tuesday 22 April. It is worth checking up on procedures for meteor scatter working if you’ve not done it before and you may find a new part of the hobby to add to your operating schedule.

The prospects for aurora continue to be raised by what seems like an almost daily supply of aurora alerts. Continue to monitor the Kp index for signs of elevated values, where Kp is above five, for radio activity. Early signs such as fluttery signals on the LF and HF bands may suggest it’s worth looking on the VHF bands for auroral activity.

As we move towards the new season it is good to get into the habit of looking for Sporadic-E. The Propquest website   shows several useful components for analysing the Es prospects.  If you look at the position of the jet streams shown on the Es blog tab, these can produce favourable conditions geographically to give a hint of the right direction in which to listen. The opening season typically favours 10m or 6m.

EME path losses are now decreasing towards perigee on Sunday 27 April. Last Friday, 18 April, saw minimum Moon declination, so Moon windows will lengthen along with peak elevation. 144MHz sky noise starts this week very high but decreases to low as the week progresses.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2025/04/17/propagation-news-20-april-2025/

(Mike Terry, UK/BDXC)