As we continue through the summer Sporadic-E season, the FT8 mode is continuing to show up more really long distance paths on the 144 MHz (2m) band. On the 11th of June 2025, there was a Sporadic-E opening on the 144 MHz band and some of the paths on FT8 from CT9ACF on the Madeira Islands to stations in Europe are shown above.
The longest distance for one Sporadic-E hop might be say 2300kms. In the map above, this is roughly a line running from the west of England to the south-east of France. Any paths beyond this to the east like say to the Netherlands (PA), Germany (DL) and Italy (I) are in the region of 2700-2900 kms and are unusual.
The really exceptional paths were from the Madeira Islands to Greece. The longest of these to SV1NZX in Athens was just over 3700kms.
Propagation Mode?? ... It's hard to be certain what propagation mode was responsible. There was certainly a Sporadic-E opening but how was the range extended to 3000+ kms?
In the past, we've seen openings like this when there has been a Sporadic-E opening from say Germany to the the south-west of Spain and Portugal and the remaining 1000kms or so to the Madeira Islands was due to a maritime duct.
The area to the west of Portugal and Morocco is well known for maritime tropo ducts which can last for days if not weeks.
The map above shows the tropo prediction at the time of the opening. It's worth noting that in the map at the beginning of this post, there are very few stations in say Portugal spotting CT9ACF. I would have expected more 'short' distance spots if there was a strong maritime duct.
Perhaps on this occasion, it was a case of double hop Sporadic-E? A chordal hop between two Sporadic-E clouds without hitting the ground in between?
Links... For more examples of long distance paths on the 2m band, see
my 144 MHz page.
Addendum: Thanks to John, G4SWX for the following detailed comment...
G4SWX writes... "There were 3 or 4 different sporadic e events in the late afternoon/early evening of 11th June. The path to Madeira to somewhere near the Spanish/Portuguese coast was almost certainly assisted by a tropospheric duct. Hepburn and F5LEN predictions although good approximations they are not always super accurate in the actual position of ducts. I have conducted very many tropo + meteor scatter tests with EA8 and the tropo predictions produce about 60% probability of a tropo path for complex dual mode propagation. Also, Hepburn and F5LEN use slightly different modelling methods so it is wise to use both at the same time. Hepburn predictions at 18:00 utc on 11th suggests that there might be paths to Madeira particularly from SE Spain EA7.
Looking at the PSK reporter flags, many stations including myself reported stations in CT and EA7 around this time. Indeed, when those in the low countries and nearby parts of Germany were working CT9ACF I was working EA8TJ in the Canaries and being heard by several other EA8 stations at just over 3000Km. This is consistent with an ES event to possibly just off the EA7/CT coast and tropo paths to the final destinations
During the time when stations in N Italy and surrounding countries were working CT9ACF I worked 7X2RF in Algiers JM16 and heard stations in the Balearic Islands EA6. This suggests that again the path from N Italy to Madeira was assisted by a maritime duct South of EA7.
The paths from Greece, SV to Madeira is a far more complex problem to analyse. There was a very intense tropo duct from Greece to Sicily and indeed ducts much further along the Mediterranean. I have attached the Hepburn plot covering the Mediterranean. It is unlikely that the duct extended much further that the Balearic Islands, so e layer reflection is likely to be the propagation from around Sardinia, IS0 to just beyond the EA7 coast. Whether the complete path was a combination of single hop ES plus tropo, one or two ducts or chordal ES plus tropo is hard to say without the LiveMuF maps at the time in question. Unfortunately, EA6VQ’s MuF Maps only allow an animation for the previous 1 hour.
73
John G4SWX"
Appendix...
a) Some of the paths over 2800kms on the 11th of June 2025 are shown below...
