HF News

We’ve had yet another week of relatively calm geomagnetic conditions. The solar
flux index has been in the 160s and despite having 14 M-class solar flares over
seven days we haven’t had any coronal mass ejections to contend with.
As a result, the daytime maximum usable frequency or MUF over a 3,000km
path has been high, reaching more than 35MHz at times.

The MUF declines after sunset, as expected, settling at about 12-13MHz,
meaning the only HF band open to DX has been 10MHz in the 30-metre band.
DX this week has included 3D2Y in Rotuma. This Pacific DXpedition has been
spotted in Europe, on 20m, 15m and 17m CW, so plenty of choice as to which
band you try.

E51SGC in Rarotonga on the Cook Islands has also been spotted across many of
the HF bands, but they will be leaving on November 24. The good news is that
the team of Stan LZ1GC and Ted LZ5QZ are moving on to Tonga as A35GC from
25 November – 7 December 2024.

Gerben (PG5M) is active on the Falkland Islands as VP8G and has been spotted
on 20m, 15m and 10m CW. He is there until November 25th so get in quick!
Next week, NOAA predicts that the SFI may rise to the mid-250s again.
Geomagnetic conditions are largely predicted to be good, although do keep an
eye on solarham.com for updates.

And don’t forget the CQ Worldwide CW contest is this weekend, the 23rd and
24th November, which should bring a lot of DX to the HF bands.

VHF and up

The weather is now in an unsettled phase with areas of low pressure bringing
alternating spells of mild wet and windy weather interspersed with colder
brighter and breezy showery weather.

This raises a couple of radio-related points; one is that we will see some very
strong and potentially damaging winds in some areas, so check daily forecasts
and make sure your mast guys are secure, and secondly an absence of any
marked high-pressure Tropo weather.

Rain and snow scatter may be worth checking on the GHz Bands in such
unsettled weather. Meanwhile, meteor scatter is worthy of greater attention as
the upcoming week’s list of showers includes the small Alpha Monocerotids
shower and the tail end of the big Leonids shower.

This introduces another potential nugget of interest in that since it is widely
accepted that meteors form the source material for Sporadic-E and, despite
being out of season in the traditional sense, the prevalence of stronger jet
streams in unsettled weather makes the next week a possible ‘watch period’ for
Es.

If you are curious about what these might look like, check out the
www.propquest.co.uk website and look for the near vertical incidence skywave
or NVIS tab for Wednesday 20th November 2024.

The two events in the middle of the day and evening both reached foEs, or the
critical frequency of the Es layer, values of near 10MHz, which could equate to
four-metre propagation on a good day, and you will see the Es blog tab upper air
charts also show a jet stream of greater than 100 knots.

For EME operators, the Moon has passed peak declination so Moon availability
and peak elevation will be falling. Path losses are high and rising towards apogee
on Tuesday the 26th. 144MHz sky noise is low all week.