Propagation News – 5 June 2016

| June 3, 2016

The solar flux index declined further this week to the mid-80s. A quick look at an image of the Sun from the Solar Dynamics Observatory on shows why. On Thursday two sunspot groups were rotating out of sight on the Sun’s limb, leaving a pretty blank disk. As a result NOAA predicts the solar flux index will diminish to 75-80 for the whole of next week.

This week has been quieter geomagnetically, with a maximum K-index of three and a low of one. As we mentioned in the last report, this week may start off very unsettled with a K-index up to five this weekend due to a geo-effective recurring coronal hole on the Sun’s surface. After a respite mid-week, next weekend may also become unsettled.

The highlight this week has been prolonged sporadic-E openings on the upper HF bands. These have brought lengthy short-skip openings on 20m and up and hopefully may continue. Rare, but relatively local, DX has included both Monaco and San Marino on 10 metres.

If you are fairly new to the hobby look around 28.500MHz for signals around mid-morning, mid to late afternoon and early evening. Also look for FM signals around 29.600MHz. Beacon hunters should look between 28.125 and 28.325MHz.

VHF and up propagation

The weather pattern is fairly slow moving and although we start with high pressure, this will get displaced to the east. This could still provide some tropo from northern Britain across to southern Scandinavia. Low pressure approaching from the Atlantic will introduce some showery weather with warmer and more humid southerly winds. If these showers are heavy and thundery they could produce good rain scatter on the Gigahertz bands.

As we said earlier, we’ve had a good start to this year for sporadic-E with many days of European sporadic-E on 50MHz upwards to 144MHz. Teatime on the 30th produced strong 144MHz signals from YU1EV and others, copied from East Anglia right over to west Wales and the Isle of Man.

Disturbed weather patterns with strong jet streams are what is required for sporadic-E, but the next week is looking quieter as the jet stream migrates to the northern parts of Europe. This could mean paths to Scandinavia more often than southern Europe as in recent weeks. If you do one thing, check the VHF bands for sporadic-E around teatime, before eating, and you’ll catch most of what develops.

With high declination, the Moon is favourably placed for EME, with low losses early in the week.

Category: GB2RS Propagation News