ARLA/CLUSTER: Steve (G0KYA) publica mapas de previsões de propagação em HF até ao fim de 2016 para o Reino Unido

[João Costa > CT1FBF]

HF Propagation

*Steve G0KYA*, the Chairman of the RSGB's Propagation Studies Committee,
has updated his hourly UK HF Propagation Predictions maps for the rest of
2016.

You can view the charts using the link from g0kya.blogspot.co.uk
<http://www.g0kya.blogspot.co.uk/>

These take into account the latest smoothed sunspot numbers from NOAA/NGDC.

Steve says: “We continue to see a steady decline in sunspot activity as we
fall away from the peak of solar cycle 24. Twelve months ago the solar flux
index peaked at 163 in May. This month it has struggled to exceed 100 and
is currently 94.

“Coupled with this, we have suffered quite badly from the effects of plasma
from solar coronal holes. These are areas of the sun with an open magnetic
field that allows plasma to escape.

“If these coronal holes are earth-facing the result can be an elevated K
index as the plasma from the high-speed solar wind stream impacts the
earth, especially if it has a negative or south-facing magnetic field,
which couples more easily.

“A high K index is usually a sign of poor HF conditions, with noisy bands
and depressed maximum usable frequencies. Any path over the poles is also
badly affected.

“This can also lead to aurora, which while not being visible in the summer,
can lead to openings on VHF,� Steve said.

He said that looking further ahead it doesn't look too good for next
weekend's RSGB HF CW National Field Day (June 4 and 5) as plasma from a
recurring solar coronal hole could push the K index up to five. This may
see the HF bands become noisy and maximum usable frequencies fall away if
the current predictions are correct.

Apart from occasional short-skip sporadic E openings on 10m, the highest
“money� band for Field Day is predicted to be 20m, with some possible
openings to the southern hemisphere on 15m.

Forty metres should also give consistent openings around Europe, with DX
being workable at night. Eighty metres may give good openings around Europe
after dark, but is unlikely to yield much DX.

Steve said that the Propagation Studies Committee is also pleased to be
able to present its latest HF propagation prediction tool, which is
currently hosted at www.predtest.uk

This is still being developed and uses the newer ITURHFPROP software as its
backend, rather than VOACAP.

“We encourage amateurs to use the system, which can also be used for
point-to-point predictions using a prototype tool called 'Proppy',� Steve
said.

*Gwyn G4FKH*, who is project manager for the new system, welcomes feedback.
Steve said the goal is for the whole system to be moved to the RSGB website
once finished.

• All propagation reports can be found at:
http://www.southgatearc.org/propagation
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