Last week was not very good for HF propagation, with the effects of an enormous
solar coronal hole, and its associated high-speed solar wind, sending the
K-index soaring. There were, however, some upsides. The initial positive phase
of a geomagnetic storm saw maximum useable frequencies rise to more than 21MHz
during the afternoon and early evening of Sunday, 7 October. These positive
phases are very hard to predict, but it is always worth checking, as a rise in
the solar wind speed and pressure, coupled with a southward facing Bz or
interplanetary magnetic field, can be signals that something is about to happen,
often before the three-hourly K-index changes. The propagation charts
at
g0kya.blogspot.com include near real-time output from the ACE spacecraft, which
can show these effects, or go to solarham.com where you’ll also find
information.
HF conditions this weekend may be unsettled again. Another
large equatorial coronal hole is moving across as the Sun rotates and became
Earth-facing on Thursday. This means we may expect unsettled geomagnetic
conditions from perhaps Saturday, the 13th. According to NOAA, conditions may
again become unsettled on Thursday, the 18th, through to Saturday, the
20th.
Barring any surprises, we will likely see no sunspots this week,
with the solar flux index hovering around 69. Unfortunately, this will probably
remain the pattern for the next few months, although now we are into October we
are seeing more DX available when conditions allow. Kenneth, TT8KO in Chad has
been a strong CW signal on 15 metres at times, although the E6Y DXpedition on
Niue in the South Pacific has proved a little more elusive for many.
VHF
and up:
This is going to be a much more autumnal week, with the best of
the recent tropo having declined by now. That leaves us with predominantly low
pressure near or just to the north of the British Isles and, at times, rather
windy weather, especially in the north of the country.
Tropo will not be
so likely next week, but there may be options for rain scatter perhaps, but we
are not very convinced that this would be a major outcome.
I guess it’s a
good time to check the antennas before the winter gales become the norm, and
perhaps try your luck on the VHF/UHF frequencies in case of any short tropo or
rain scatter events. Or why not make a winter resolution to learn Morse for the
UHF and microwave bands, or perhaps set up your station for digital modes, where
such QSOs can make use of bands that may be dead or marginal to voice
modes.
The Moon is at minimum declination tomorrow and at apogee on
Wednesday so it’s a poor week for EME, with short, low elevation passes and high
losses.
October continues to produce meteor showers, with the Eta
Geminids, a small one, peaking on Thursday followed by the Orionids a week this
Sunday. But neither are much to get excited about due to low meteor
rates.
rsgb.org
