Last week, the solar flux index continued in the mid-70s, with a single sunspot
group making its way across the visible disk.
Compare and contrast this with the
same week last year, when there were actually five sunspot groups visible. This
confirms, as it we didn’t know, that Solar Cycle 24 continues to decline. The
current estimates for sunspot minimum place it around 2019 to 2020, so get used
to more of the same.
The good news last week was
that conditions were more geomagnetically stable, with the K-index mostly around
one after Monday, the 7th. This meant that there was DX to be had, including
some short-lived openings to the Far East on 20 and 30 metres around
1800hrs.
Milton, ZP9CTS in Paraguay was
also worked by Tony, G4CJC on Tuesday using the new digital mode FT8 on 10
metres.
Next week may start off
unsettled due to another solar coronal hole, which became Earth-facing on
Wednesday. This suggests unsettled geomagnetic conditions could occur from
Friday, the 11th, and run into this weekend. This could spark auroral
conditions, but may ultimately result in depressed maximum useable
frequencies.
Once the weekend is over, next
week should be more settled and conditions may settle. Look for DX openings on
30, 20, and 17 metres, with occasional sporadic E openings on higher bands at
times.
VHF and up:
The big problem with multiple
weather models is that they usually predict ridges of high pressure and troughs
across the country at different times. It’s best therefore, to provide
generalised operating guidance for the different weather types.
This week, the ridges of high
pressure will tend to favour the south of the country for tropo, principally
into the continent and across Biscay to Spain. The troughs and lows usually
bring rain scatter and there’s been some good examples with the heavy thundery
downpours lately. Look for heavy rain, shown as bright colours on the many
online rainfall radars, to get the best from any large storm events.
The Perseids passed their peak
at the weekend, but activity will still be high over the next few days for
meteor scatter enthusiasts.
Sporadic E is still hanging on into the last part
of the season with a few openings on most days, but not necessarily reachable
from the UK. It’s quite likely that the unsettled weather currently bodes well
for sporadic E, since the powerful upper atmosphere jet streams that drive the
rainy weather are also good for sporadic E.
The lunar cycle continues on
its predictable way. Now, and for the next few years, lowest path losses are
coinciding with highest declination in the Northern Hemisphere. This means that
Moon windows are longest when losses are at their lowest. This week should be
good for EME, with falling losses as we move towards perigee and maximum
declination on Friday.
