propagation

  • HF News

    Summer Sporadic E brought some unusual short-skip propagation to 20 metres this week, with contacts being enabled between parts of the UK.

    Signals between Southern England and Scotland were very loud mid-morning after an Es cloud settled over the British Isles on Monday.

    These UK openings are hard to predict, but can bring short-skip on paths between the extreme ends of the United Kingdom on frequencies up to and including 10 metres.

    Otherwise, F-layer propagation was a little lacklustre with zero sunspots and slightly unsettled geomagnetic conditions bringing maximum useable frequencies down to 20m and lower at times.

    Next week, NOAA predicts the solar flux index will remain in the mid-to-low 70s. We may expect unsettled geomagnetic conditions this weekend and Monday the 16th due to a coronal hole that became Earth-facing on Thursday the 12th.

    Another potentially-active region will begin to turn into Earth view this weekend. This is a plage, a brighter region of the Sun’s chromosphere typically found in regions near sunspots.

    At the moment there are no visible sunspots to report in the region and solar activity may continue at lower levels.

    Twenty metres remains the most reliable DX band during the day, although “most reliable” is a relative term! Forty and thirty metres are worth checking after dark.

    For more accurate predictions it is worth checking out voacap.com and predtest.uk, both of which can handle SSB, CW and FT8 predictions.

    Don’t forget the FIFA World Cup special event stations will no doubt finish on Sunday, so get in quick!

    VHF and up

    The weather charts are starting to show subtle changes this week as the high pressure of recent weeks is not quite so dominant. But it is still there in parts and should continue to provide some occasional Tropo.

    The weakness of the high will allow some showers or weak fronts to become involved, but as this is not a widespread affair any rain scatter for the GigaHertz bands will be fairly limited.

    The unsettled part of the story will mean fronts and their associated jet streams might put in an appearance. There may be one jet stream over northwestern Britain for a brief time this weekend, and another one through the Mediterranean, but this is also a fairly weak pattern.

    The end result is that Sporadic E may not have all the weather ingredients in the right place and you’ll need to check the beacons and clusters for activity levels. Remember the season can last into late August on 6m, so there’s still time for further openings, even if this week underperforms.

    There are no meteor showers this week so stick to the early morning random peak when the earth is rotating towards the orbital plane meteor flux for the best chances of meteor shower contacts.

    We are now past Moon perigee and maximum declination for this lunar month. Declination is positive until Wednesday and losses will increase as the week progresses. This means EME conditions will be best in the first half of the week.

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