RSGB
January 5, 2018
Last week the solar flux
index (SFI) hovered around the 70 mark, reflecting the lack of sunspots. Given
that the SFI doesn’t really fall below about 65-66 at sunspot minimum, this
shows the distinct lack of solar activity at this time. This meant that the
lower bands were the ones to see the most activity, with 80 and 40 metres
showing just how well they can work during the winter. There were reports of the
US being worked on 80 metres at sunrise and on 40 metres during late afternoon.
Japan was also worked on 40 metres. This month will offer very similar
propagation to December on the low bands so make sure you don’t miss it.
There were also reports of
sporadic E openings into Europe on the HF bands. Winter sporadic E can often
bring strong short-skip openings from 40 up to 10 metres, as well as on the 6m
band, as you will hear later.
The SFI is predicted to remain
around 70 next week, so expect more of the same, propagation-wise.
Unsettled geomagnetic conditions
are forecast for around the seventh and eighth, due to a high-speed solar wind
stream from a recurrent coronal hole. The 23th and 14th may also be unsettled,
with a possible maximum K-index of five, so look for auroral-type noisy
conditions, and depressed maximum usable frequencies after a potential
short-lived upswing after the enhanced solar wind hits.
VHF and up:
The New Year starts with a hint of
tropo promise as high pressure drifts across the north of the country this
weekend. Conditions in such winter highs may not always deliver good results and
this one could be a bringer of shallow surface inversionPropagation News – 7 January 2018s with only limited
tropo lift potential. This high will soon be replaced by the return of low
pressure and more unsettled conditions during next week, so look for rain
scatter on the microwave bands.
Last week saw some good 50MHz
sporadic E into Europe, mainly from western Britain and one reported path within
Europe on 70MHz. This is a timely reminder that, although rare, sporadic E is
possible outside of the traditional high summer season, so keep looking!
After last week’s short
Quadrantids meteor shower we are entering the annual low in sporadic meteor
activity that lasts until the Lyrids shower at the end of April, so you’ll need
to work hard for meteor scatter contacts for a while.
Moon declination goes negative on
Monday and we are just a week away from its apogee, the point at which the Moon
is furthest from the Earth, so EME opportunities will be short and path losses
will increase as the week progresses.
http://rsgb.org/main/blog/news/gb2rs/propagation-news/2018/01/05/propagation-news-7-january-2018
