Over the last week we had nearly ideal solar conditions for HF propagation. These included low geomagnetic indices and a reasonable solar flux index, hovering around the 150 mark.<\/p>\n
Other solar events of note included six M-class solar flares.<\/p>\n
The only stumbling block is the time of year, with summer seeing lower maximum usable frequencies, or MUFs, and poorer propagation due to changes in ionospheric chemistry. We will have to wait another month or so to see conditions really pick up.<\/p>\n
The main HF DX this week has been T30TTT from Western Kiribati, mainly on FT8 and CW and focusing on the 20 and 17m bands. TJ1GD from Cameroon was also worked on the 17m band using FT8. E51KEE on the South Cook Islands was logged on the 17 and 15m bands using CW. And finally, AH6KO in Hawaii was worked on the 15m band using CW.<\/p>\n
But this may all be set to change.<\/p>\n
A coronal mass ejection observed on Tuesday 5 August may deliver a glancing blow to the Earth’s geomagnetic field. This may also coincide with an expected high-speed stream from a very large coronal hole on the Sun\u2019s surface. NOAA predicts that the Kp index could rise to 5 or 6.<\/p>\n
The hole is so large and elongated that we could see unsettled conditions occurring in the coming week.<\/p>\n
NOAA predicts unsettled geomagnetic conditions from the 11 to the 14 August. It also predicts more unsettled conditions from the 18 to the 22 August, with a maximum Kp index of 5. Expect reduced MUFs and poor HF conditions, especially for paths over the poles.<\/p>\n
VHF and up<\/strong><\/p>\n The main setting for the weather pattern over the next week is a tendency for high pressure in the south and lower pressure to the north of Britain. There may be some input from a low over France around the middle of the week. This might introduce some thundery showers and a chance of rain scatter on the GHz bands.<\/p>\n Meanwhile, occasional weak frontal systems will bring patchy rain to the far northwest, but probably not so good for rain scatter opportunities.<\/p>\n The Tropo at this time of year can be very good around the coasts and occasionally inland overnight. However, it tends to weaken inland during the heating of the day. Out at sea, temperatures remain fairly constant and maintain an ideal cool moist layer at the sea surface overlain by a layer of warm dry air from the land. This provides Tropo 24 hours a day, seven days a week.<\/p>\n Mid-August is good for meteor scatter with the peak of the Perseids on the Tuesday night of the 12 and 13 August. Apart from digital-mode QSOs, it\u2019s good for late summer evening sky watching. It is fascinating to listen on the VHF SSB meteor scatter frequencies while watching to get the full experience. It\u2019s a broad shower, so don\u2019t worry if you must pick a night either side of the peak.<\/p>\n The chances of aurora are not zero with further minor alerts to remind us that it’s worth checking. The main mode for DX is probably still going to be Sporadic-E, which has roughly another four weeks to run. Don\u2019t expect something every day as it tends to become more random towards the latter part of the season.<\/p>\n Moon declination is negative, but rising again, so Moon window lengths and peak elevation will increase. Path losses are also falling, reaching minimum at perigee on Thursday 14 August. 144MHz sky noise is low to moderate all next week.<\/p>\n","protected":false},"excerpt":{"rendered":" Over the last week we had nearly ideal solar conditions for HF propagation. These included low geomagnetic indices and a reasonable solar flux index, hovering around the 150 mark. Other solar events of note included six M-class solar flares. The only stumbling block is the time of year, with summer seeing lower maximum usable frequencies, […]<\/p>\n","protected":false},"author":20377,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-41738","post","type-post","status-publish","format-standard","hentry","category-propagation-news"],"_links":{"self":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/posts\/41738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/users\/20377"}],"replies":[{"embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/comments?post=41738"}],"version-history":[{"count":1,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/posts\/41738\/revisions"}],"predecessor-version":[{"id":41739,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/posts\/41738\/revisions\/41739"}],"wp:attachment":[{"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/media?parent=41738"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/categories?post=41738"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rsgb.org\/main\/wp-json\/wp\/v2\/tags?post=41738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}