Propagation News – 7 December 2014

| December 5, 2014

As predicted, HF conditions were very good for the CQ Worldwide contest last weekend, although NOAA were wrong with their predicted solar flux index. Instead of 135 it was actually 177. There were no major flares or coronal mass ejections to upset the ionosphere with the result that all of the HF bands were very active, with 10m giving CW contacts from the UK into the far west of the USA, including California, W6 and Washington State, W7.

This week the sun looks like it may be less active, but there are a couple of spots that will rotate into view. As a result NOAA/USAF predicts the solar flux index will be in the range 160 to 180.

Geomagnetic conditions are predicted to be unsettled due to a recurrent coronal hole with the Kp hitting four at middle latitudes towards the end of the week. This could result in poor conditions on HF on Thursday and or Friday with potential auroral openings on VHF.

NOAA in the USA has said that it looks like solar maximum occurred in April, although it was modest compared with the previous cycle. This can only be only be confirmed in hindsight as we see what the coming months bring in terms of solar activity.

Sadly, the slight improvement in VHF/UHF fortunes of last week are rapidly fading as the next series of strong lows move across the Atlantic towards the British Isles. With little prospect of high pressure systems, it seems likely that conditions will be flat for much of the coming week as wet and windy weather destroys any chance of significant inversions forming.

To leave it on a slight upbeat, some of the models do suggest a weak ridge towards the very end of the week, but a lot can change between now and then.

There is plenty to keep the VHFer busy though, as the Geminids meteor shower reaches its peak next Friday and Saturday. All this coming week we should see evidence of the shower with improved meteor scatter conditions on the lower VHF bands.

For EME operators, the Moon reaches its highest declination today, Sunday, declining next week, so still plenty of Moon time, at the cost of high losses as the Moon reaches apogee, its furthest point from earth, on Friday.

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

Category: GB2RS Propagation News