Propagation News – 18 January 2015

| January 16, 2015

This week the solar flux index has been down a little compared with the pre-Christmas period. As the report was being prepared it stood at 142, with NOAA predicting it will decrease to 130 by the end of the week.

There are currently no new visible sunspots rotating into view on the sun’s surface, which explains the predicted reduction in solar flux. Geomagnetic conditions have been a little quieter too, with the Ap index keeping well below 20. This may continue next week as the current crop of sunspots appears quite stable.

Together this means we may be in for reasonably-settled HF conditions over the next seven days.

Paths to the eastern seaboard of the United States will have an 80% probability of success in the afternoon on 15m, that’s 21MHz. The more difficult trans-polar short path route to California will offer around 30% probability on 17m, that’s 18MHz, around 1600-1700hrs.

January remains a good month for DX on 160, 80 and 40 metres, although the higher solar flux indices and more unsettled geomagnetic conditions have meant that the lower bands have been suffering, compared with sunspot minimum.

Meteorologist Jim, G3YLA reports that the weather for the next week is dominated by a true winter pattern with frost and snow likely. On some of the calm, frosty nights with clear skies there is likely to be a strong surface temperature inversion developing that may give rise to some slight enhancements in VHF/UHF tropo performance.

Otherwise, it will be too windy generally, although there is a possible ridge of high pressure next weekend over north western Scotland and western Ireland and if that builds south eastwards we may benefit in the following week.

For EME operators, the Moon’s declination increases throughout the coming week, giving longer Moon windows, with losses reaching a minimum midweek. The moon is close to the sun on Tuesday, making Thursday and Friday the best days.

There are no significant meteor showers this week and Sporadic-E openings are very unlikely, but there’s still amateur satellites to use. A moderate station can make QSOs via FUNcube, so there’s always something to try at VHF and up.

And that’s all this week from the propagation team.

Category: GB2RS Propagation News