We had quite a quiet week with the Sun with zero sunspots and
a settled geomagnetic field. The solar wind speed was slow, between 280
and 330km per second, and its magnetic field was weak, with no
significant negative deflections in its important north-south Bz
direction. Therefore, the resultant geomagnetic activity was settled.
On the 21st a sunspot appeared around the Sun’s limb. Now classified
as sunspot group 2767, on Thursday it contained one sunspot, but its
simple uni-polar magnetic signature suggests it is non-threatening.
We do expect the Kp index to rise on Friday, the 24th, due to the
arrival of a coronal hole high speed stream. Modest magnetic enhancement
is also forecast for 25 July with the possible arrival of a slow CME
from the 19th.
Expect a possible pre-aurora enhancement followed by the potential
for suppressed maximum usable frequencies over the weekend and into
early next week.
HF conditions have been generally lacklustre, but Laurie, G3UML
reports that WH6FXL and WA6QDQ/KH6, both in Hawaii, were both quite
readable signals on 20m SSB at 0800 on Wednesday. Tom, GM4FDM reports
working two JAs on 17m using his newly-erected dipole. The 10m UK Net
group on Facebook also reported an FT8 opening to Japan on Monday as
This just goes to show that you shouldn’t just write off the summer as being no good for DX.
Next week NOAA
predicts the solar flux index will remain in the high 60s with the Kp
index between two and three. This generally suggests that HF conditions
will remain similar to last week. Expect sporadic E openings on 10
metres to continue, although not at the rate that we had earlier in the
VHF and up
A series of low-pressure systems passing close by northern Scotland
and various fronts crossing the country mean that there are likely to be
few opportunities for tropo this week. High pressure is displaced to
the south over France so any tropo will be mostly likely from southern
England into the continent or across Biscay to Spain. That brings rain
scatter on the GHz bands onto the agenda for many regions of the UK at
some time or other during the coming week.
Sporadic E still warrants a mention, but it is becoming more elusive
as we move towards August. It’s not a ‘no chance’, but it will need some
strategy for being in the right place at the right time. The best
options will be to monitor 10m or 6m mid-morning and again late
afternoon or early evening. Paths on FT8 will prove good indicators of
which direction might deliver as the Es develops.
With the Moon declination negative and falling further as the week
progresses, Moon visibility windows will shorten and peak elevation will
be just 32 degrees this Sunday and falling, leading up to minimum
declination a week from Sunday.
Perigee will be Saturday, 1 August, so path losses are now
increasing. 144MHz sky noise peaks at 2,500 Kelvin on Friday, so low
noise preamps won’t help you that day.
The Southern Delta Aquarids meteor shower has a broad peak from the
26th to the 31st with a Zenithal Hourly Rate of 25, so look for enhanced
meteor scatter activity in the coming week. In Europe, the shower
radiant is above the horizon at night or in the early mornings.
Category: GB2RS Propagation News