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HF News
It looks like the Space Weather Prediction Centre, which supplies the forecasts for NOAA, were a little over cautious last week.
Despite predicting geomagnetic disturbances we actually ended up with quite a calm week. The Kp index rose to 3.33 on a few occasions, but that was it. We ended up with settled geomagnetic conditions and a solar flux index in the 120-130s. At the time of writing, a warning about the impact of a CME, which left the Sun on June 28th, appeared to come to nothing.
This made a much-needed change to the unsettled conditions of previous weeks.
As a result MUFs over a 3,000km path have been above 21MHz at times. At night, MUFs over the same path have been consistently above 14MHz, which is normal for this time of year.
In the summer we can expect to see night-time MUFs being consistently higher than in the Winter, due to a change in the ionospheric chemistry. Unfortunately, this also means that daytime MUFs are lower than in Winter, leaving 28MHz open to Sporadic E instead.
Looking at DXMaps.com, its appears that most Sporadic E openings on 10m have favoured the South East towards Italy, Turkey and Greece.
Back to F2-layer propagation and on 20m, E51JD South Cook Islands was spotted on SSB by Laurie G3UML on Thursday morning. While KH7AL/KH9 on Wake Island has also been worked on 20m FT8. Meanwhile, T30TTT on Kiribati has also been active on 20m FT8.
Next week, NOAA predicts that the SFI will be in the range 125-145. Geomagnetic conditions are predicted to be quiet, apart from the period around the 11th and 12th July when the Kp index may rise to four.
VHF and up
This hot weather has provided some nice marine Tropo around the coasts recently as hot dry air advects across the cooler moist surface layer.
We have also been able to see the duct move inland in the evenings. The hybrid weather pattern of low pressure to the north of Britain and high pressure to the south will continue to produce some Tropo paths, particularly across the Channel, Biscay and North Sea.
Northern areas of Britain will see occasional fronts and active weather systems, together with breezier weather, making Tropo unlikely here. The higher pressure to the south means that rain scatter may not feature much unless isolated thunderstorms develop when weak weather fronts eventually reach these southern areas.
In the north it’s a different matter, and there could be some heavier rain that might produce some rain scatter on the GHz bands.
Meteor scatter has done well during June with several important showers to boost chances. July offers two showers, the first is the low-hourly-rate Alpha Capricornids and the second is the Delta Aquariids which both peak around the 30th of July, so we have a while to wait.
There have been some minor auroral events recently and it’s always possible that solar activity could lift the Kp index high enough, but we are not expecting great things. Keep a check on the Kp index on www.spaceweather.com to see if anything is happening.
The Sporadic-E season has had occasional good days, but for much of the time the focus of activity has been too far into Europe for the whole country to take advantage of it. To begin the coming week, the position of the jet streams suggests paths to northern Europe and the Baltic offer best results, before the emphasis shifts to the Balkans and Italy and later, to Iberia.
The Moon reaches apogee on Saturday the 7th, where path losses are at their highest. Moon declination is negative all week with lowest (most negative) on Wednesday the 7th. 144MHz sky noise is moderate but increasing to a high of around 2300K next Wednesday.