Propagation News – 22 December 2019

| December 20, 2019

We have a slightly different twist on the HF propagation report this week. At Christmas, we usually help you work the Father Christmas special event station in Lapland, but we are not sure if it is active this year. Instead, there are seven special Christmas stations operating in Spain until the 6th of January 2020. These are AO1XMA, AO2XMA, AO3XMA, AO4XMA, AO5XMA, AO7XMA, and AO8XMA. These are all a fairly easy one-hop distance away from the UK. During daylight hours forecasts that 7MHz and 10MHz may be the best bands for a contact. Twenty metres, or the 14MHz band, may also offer opportunities around the middle of the day. After sunset the MUF on this path drops to around 5-5.5MHz, so 80m or the 3.5MHz band, may provide the best chance.

At the time this report was prepared, we were not too sure exactly where the stations are located. All are listed as being organised by Federacion Digital EA in Barcelona. As Spain is quite large, it could be that propagation on the higher bands favours any station located in the south of Spain.

NOAA predicts a solar flux index of 70 for the next two weeks and reasonably-settled geomagnetic conditions with a Kp index of two. The disruption seen on Thursday 19th should quieten as Earth leaves the high-speed solar wind stream from a coronal hole.

There is the potential for a new sunspot that has been seen forming in the north-west quadrant on the Sun. But this may have completely disappeared by the time this report is being read out, so don’t get your hopes up!

VHF and up

The weather models diverge markedly by the middle of next week. Starting with the period that remains in-step, which takes us through this weekend and up to Christmas, we have low pressure in the vicinity of northern Britain eventually drifting into the North Sea by Christmas. This will mean rain or showers and perhaps some rain scatter on the microwave bands, but little sign of tropo.

However, one of the models produces a reasonable high over the country by Christmas Day, which tries to hang on nearby the UK to the end of the week. This could bring some slightly enhanced tropo, although it’s forming in cold air and may only provide limited lift conditions, but at least it’s a chance.

The other model evolution retains the low pressure story, so no tropo and a dominant low over the nearby Atlantic keeping the weather breezy and with rain in the west and north, so the rain scatter theme persists.

There are continuing signs of quite strong jet stream activity over southern Britain and the near continent, which in the summer is usually a shoe-in for Sporadic-E. In the winter it’s much less common, but not entirely without hope, especially for digital modes on 10m and perhaps up to 6m if we’re really lucky.

Moon declination is negative and falling further this week so Moon availability will reduce. Perigee was last week so path losses will continue to rise. The 144MHz sky temperature will be high, leading to Thursday morning which sees the Moon and Sun very close.

There is just the small Ursids meteor shower peaking tomorrow, but the massive Quadrantids shower gets under way on Friday leading up to its 110 zenithal hourly rate peak over the third and fourth of January.

Category: GB2RS Propagation News