Last week saw the solar flux index in the low to mid-70s. Geomagnetic conditions
were generally quiet earlier in the week, with some choice DX to be had. Andy,
M0NKR reported working the Marshall Islands in the Pacific on 20m CW at 07:00
UTC on Wednesday, while Del, W8KJP in Florida, USA, was heard by G0KYA on 40m CW
at 22:21 UTC using a simple wire antenna. But the good conditions didn’t last
and the ionosphere became disturbed on Thursday 17th due to the effects of a
high-speed solar wind stream from a large high-latitude coronal hole on the Sun.
This had a very strong south-facing magnetic field component that meant it more
easily coupled with the Earth’s magnetic field. The K-index surged to five and
remained like that for at least nine hours, driving maximum usable frequencies
down to around 14 MHz and causing very noisy bands. Next week, NOAA predicts the
solar flux index will be in the high 60s and, after an unsettled start,
geomagnetic conditions may settle for the rest of the week.
Monday the 21st brings a total
solar eclipse, which will be visible across the USA. A QSO party is planned so
many US stations may be active. The partial eclipse starts at 1546UTC and ends
at 2104 UTC. Totality will move east across the US, starting at 16:48 UTC and
ending in the Atlantic at 2001UTC. A feature on the eclipse appeared in the
August edition of RadCom, but there is a lot more information on the web. It is
not known whether any propagation effects will be observable from the UK, but it
is a rare opportunity to check.
VHF and up:
The unsettled
weather crossing the country this weekend will contain some remnants of
Hurricane Gert. This means some very warm and moist tropical air could produce
some heavy rain. Gigahertz band rain scatter may be an option, but as the next
high pressure builds in from the west towards mid-week, tropo should become
available. This should be to the south and south-west across southern UK and
Biscay. The rest of the week will probably see high pressure remaining just to
the west of the UK, so any tropo will be biased to that side of the country,
with showery activity over the east, closest to the low pressure over Denmark.
Sporadic E is still looking viable, with a strong jet stream over the UK
and near continent, although this may weaken after mid-week, meaning better
sporadic E prospects before then. The end of the main sporadic E season is not
far off now, so every event is worth chasing. Check beacons on 10m or look for
short skip on 20m, then probe that direction on 6m for any sporadic E. If you
don’t call, the DX may not know the band is open.
Even though the
Perseids shower is well behind us, random meteor rates are still at their
highest of the year so don’t give up on meteor scatter just yet. Moon
declination goes negative on Thursday and losses are increasing so get your EME
QSOs in early this week before the Moon gets too low in the sky.
