This week saw mixed HF propagation conditions. We were right to predict a
geomagnetic disturbance for last weekend, although the plasma hit the Earth
right at the end of National Field Day. This led to widespread aurora as the
K-index hit five and then six.
Propagation during field day was
lacklustre due to a lack of sunspots and the seasonal doldrums. But there has
been some decent propagation and excellent DX this week. Andy, M0NKR reports
working 9Y4D in Trinidad on 6m, possibly via multi-hop sporadic E, and XR0YS
Easter Island on 10m, which, after careful examination, was most likely F layer
propagation.
This week the solar flux index is
predicted to be in the range 85-95, although on Thursday there was only one
sunspot group visible.
Geomagnetic disturbances due to coronal
hole activity are predicted to remain an issue this weekend, with the K-index
possibly increasing to four. Next week may also remain unsettled, with the
K-index predicted to hit five on Friday the 17th.
We are now entering the period for six
metre summer solstice short path propagation when signals from Asia may be heard
in Europe from over the North Pole. Stations equipped with six metres are
encouraged to get on the band as this, plus multi-hop sporadic E, can bring some
surprises.
VHF and up propagation news:
Propagation folklore has the first week
in June high on the list of sporadic E activity. Last week, we had some fine
sporadic E, some excellent tropo to the north and GHz-band rain scatter to the
near continent. The northerly tropo coupled signals into the aurora giving some
remarkable mixed mode DX for the lucky few.
Next week, we may struggle to achieve
any tropo of note, as low pressure is due to move into the British Isles. This
will bring showery weather ending the tropo spell over the North Sea.
A new high to the south-west late in the
week may allow paths to the south across Biscay and down past Portugal to the
west coast of North Africa.
There should be plenty of opportunities
for sporadic E during next week when weather elements are favourable. The
principal elements are jet streams, and it is likely that these will be located
over the near continent as the weather turns unsettled.
This could bring propagation towards the
Balkans and round through Italy to Iberia. Remember that there are usually two
main periods of activity, late morning and early evening, but very active events
can last for much of the day.
(RSGB)
